Add a few debug statements that were useful to me when debugging why the
glibc probes interface wasn't getting used.
Change-Id: Ic20744f9fc80a90f196896b0829949411620c540
From glibc 2.35 and later, the "map_failed" stap probe is no longer
included in glibc. The removal of the probe looks like an accident,
but it was caused by a glibc commit which meant that the "map_failed"
probe could no longer be reached; the compiler then helpfully
optimised out the probe.
In GDB, in solib-svr4.c, we have a list of probes that we look for
related to the shared library loading detection. If any of these
probes are missing then GDB will fall back to the non-probe based
mechanism for detecting shared library loading. The "map_failed"
probe is include in the list of required probes.
This means that on glibc 2.35 (or later) systems, GDB is going to
always fall back to the non-probes based mechanism for detecting
shared library loading.
I raised a glibc bug to discuss this issue:
https://sourceware.org/bugzilla/show_bug.cgi?id=29818
But, whatever the ultimate decision from the glibc team, given there
are version of glibc in the wild without the "map_failed" probe, we
probably should update GDB to handle this situation.
The "map_failed" probe is already a little strange, very early
versions of glibc didn't include this probe, so, in some cases, if
this probe is missing GDB is happy to ignore it. This is fine, the
action associated with this probe inside GDB is DO_NOTHING, this means
the probe isn't actually required in order for GDB to correctly detect
the loading of shared libraries.
In this commit I propose changing the rules so that any probe whose
action is DO_NOTHING, is optional.
There is one possible downside to this change, and that concerns 'set
stop-on-solib-events on'. If a probe is removed from glibc, but the
old style breakpoint based mechanism is still in place within glibc
for that same event, then GDB will stop when using the old style
non-probe based mechanism, but not when using the probes based
mechanism.
For the map_failed case this is not a problem, both the map_failed
probe, and the call to the old style breakpoint location were
optimised out, and so neither event (probes based, or breakpoint
based) will trigger. This would only become an issue if glibc removed
a probe, but left the breakpoint in place (this would almost certainly
be a bug in glibc).
For now, I'm proposing that we just don't worry about this. Because
some probes have actions that are not DO_NOTHING, then we know the
user will always seem _some_ stops when a shared library is
loaded/unloaded, and (I'm guessing), in most cases, that's all they
care about. I figure when someone complains then we can figure out
what the right solution is then.
With this commit in place, then, when using a glibc 2.35 or later
system, GDB will once again use the stap probes for shared library
detection.
Reviewed-By: Lancelot SIX <lancelot.six@amd.com>
When looking up names, GDB needs to stay within one linker namespace to
find the correct instance in case the same name is provided in more than
one namespace.
Modify svr4_iterate_over_objfiles_in_search_order() to stay within the
namespace of the current_objfile argument. If no current_objfile is
provided (i.e. it is nullptr), iterate over objfiles in the initial
namespace.
For objfiles that do not have a corresponding so_list to provide the
namespace, assume that the objfile was loaded into the initial namespace.
This would cover the main executable objfile (which is indeed loaded into
the initial namespace) as well as manually added symbol files.
Expected fails:
- gdb.base/non-lazy-array-index.exp: the expression parser may lookup
global symbols, which may result in xfers to read auxv for determining
the debug base as part of svr4_iterate_over_objfiles_in_search_order().
- gdb.server/non-lazy-array-index.exp: symbol lookup may access the
target to read AUXV in order to determine the debug base for SVR4
linker namespaces.
Known issues:
- get_symbol_address() and get_msymbol_address() search objfiles for a
'better' match. This was introduced by
4b610737f0 Handle copy relocations
to handle copy relocations but it now causes a wrong address to be
read after symbol lookup actually cound the correct symbol. This can
be seen, for example, with gdb.base/dlmopen.exp when compiled with
clang.
- gnu ifuncs are only looked up in the initial namespace.
- lookup_minimal_symbol() and lookup_minimal_symbol_text() directly
iterate over objfiles and are not aware of linker namespaces.
Introduce a new qXfer:libraries-svr4:read annex key/value pair
lmid=<namespace identifier>
to be used together with start and prev to provide the namespace of start
and prev to gdbserver.
Unknown key/value pairs are ignored by gdbserver so no new supports check
is needed.
Introduce a new library-list-svr4 library attribute
lmid
to provide the namespace of a library entry to GDB.
This implementation uses the address of a namespace's r_debug object as
namespace identifier.
This should have incremented the minor version but since unknown XML
attributes are ignored, anyway, and since changing the version results in
a warning from GDB, the version is left at 1.0.
In glibc, the r_debug structure contains (amongst others) the following
fields:
int r_version:
Version number for this protocol. It should be greater than 0.
If r_version is 2, struct r_debug is extended to struct r_debug_extended
with one additional field:
struct r_debug_extended *r_next;
Link to the next r_debug_extended structure. Each r_debug_extended
structure represents a different namespace. The first r_debug_extended
structure is for the default namespace.
1. Change solib_svr4_r_map argument to take the debug base.
2. Add solib_svr4_r_next to find the link map in the next namespace from
the r_next field.
3. Update svr4_current_sos_direct to get the link map in the next namespace
from the r_next field.
4. Don't check shared libraries in other namespaces when updating shared
libraries in a new namespace.
5. Update svr4_same to check the load offset in addition to the name
6. Update svr4_default_sos to also set l_addr_inferior
7. Change the flat solib_list into a per-namespace list using the
namespace's r_debug address to identify the namespace.
Add gdb.base/dlmopen.exp to test this.
To remain backwards compatible with older gdbserver, we reserve the
namespace zero for a flat list of solibs from all namespaces. Subsequent
patches will extend RSP to allow listing libraries grouped by namespace.
This fixes PR 11839.
Co-authored-by: Lu, Hongjiu <hongjiu.lu@intel.com>
Whenever we call locate_base(), we clear info->debug_base directly before
the call. Thus, we never cache the base location as locate_base() had
intended.
Move the svr4_have_link_map_offsets() check into elf_locate_base(), inline
locate_base() at all call sites, and remove it.
With the test-case included in this patch, we run into:
...
(gdb) target remote localhost:2347^M
`target:twice-connect' has disappeared; keeping its symbols.^M
Remote debugging using localhost:2347^M
warning: Unable to find dynamic linker breakpoint function.^M
GDB will be unable to debug shared library initializers^M
and track explicitly loaded dynamic code.^M
Reading /usr/lib/debug/.build-id/$hex/$hex.debug from remote target...^M
0x00007ffff7dd4550 in ?? ()^M
(gdb) PASS: gdb.server/twice-connect.exp: session=second: gdbserver started
FAIL: gdb.server/twice-connect.exp: found interpreter
...
The problem originates in find_program_interpreter, where
bfd_get_section_contents is called to read .interp, but fails. The function
returns false but the result is ignored, so find_program_interpreter returns
some random string.
Fix this by checking the result of the call to bfd_get_section_contents.
Tested on x86_64-linux.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29652
There's a flaw in the interaction of the auxv caching and the fact that
target_auxv_search allows reading auxv from an arbitrary target_ops
(passed in as a parameter). This has consequences as explained in this
thread:
https://inbox.sourceware.org/gdb-patches/20220719144542.1478037-1-luis.machado@arm.com/
In summary, when loading an AArch64 core file with MTE support by
passing the executable and core file names directly to GDB, we see the
MTE info:
$ ./gdb -nx --data-directory=data-directory -q aarch64-mte-gcore aarch64-mte-gcore.core
...
Program terminated with signal SIGSEGV, Segmentation fault
Memory tag violation while accessing address 0x0000ffff8ef5e000
Allocation tag 0x1
Logical tag 0x0.
#0 0x0000aaaade3d0b4c in ?? ()
(gdb)
But if we do it as two separate commands (file and core) we don't:
$ ./gdb -nx --data-directory=data-directory -q -ex "file aarch64-mte-gcore" -ex "core aarch64-mte-gcore.core"
...
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x0000aaaade3d0b4c in ?? ()
(gdb)
The problem with the latter is that auxv data gets improperly cached
between the two commands. When executing the file command, auxv gets
first queried here, when loading the executable:
#0 target_auxv_search (ops=0x55555b842400 <exec_ops>, match=0x9, valp=0x7fffffffc5d0) at /home/simark/src/binutils-gdb/gdb/auxv.c:383
#1 0x0000555557e576f2 in svr4_exec_displacement (displacementp=0x7fffffffc8c0) at /home/simark/src/binutils-gdb/gdb/solib-svr4.c:2482
#2 0x0000555557e594d1 in svr4_relocate_main_executable () at /home/simark/src/binutils-gdb/gdb/solib-svr4.c:2878
#3 0x0000555557e5989e in svr4_solib_create_inferior_hook (from_tty=1) at /home/simark/src/binutils-gdb/gdb/solib-svr4.c:2933
#4 0x0000555557e6e49f in solib_create_inferior_hook (from_tty=1) at /home/simark/src/binutils-gdb/gdb/solib.c:1253
#5 0x0000555557f33e29 in symbol_file_command (args=0x7fffffffe01c "aarch64-mte-gcore", from_tty=1) at /home/simark/src/binutils-gdb/gdb/symfile.c:1655
#6 0x00005555573319c3 in file_command (arg=0x7fffffffe01c "aarch64-mte-gcore", from_tty=1) at /home/simark/src/binutils-gdb/gdb/exec.c:555
#7 0x0000555556e47185 in do_simple_func (args=0x7fffffffe01c "aarch64-mte-gcore", from_tty=1, c=0x612000047740) at /home/simark/src/binutils-gdb/gdb/cli/cli-decode.c:95
#8 0x0000555556e551c9 in cmd_func (cmd=0x612000047740, args=0x7fffffffe01c "aarch64-mte-gcore", from_tty=1) at /home/simark/src/binutils-gdb/gdb/cli/cli-decode.c:2543
#9 0x00005555580e63fd in execute_command (p=0x7fffffffe02c "e", from_tty=1) at /home/simark/src/binutils-gdb/gdb/top.c:692
#10 0x0000555557771913 in catch_command_errors (command=0x5555580e55ad <execute_command(char const*, int)>, arg=0x7fffffffe017 "file aarch64-mte-gcore", from_tty=1, do_bp_actions=true) at /home/simark/src/binutils-gdb/gdb/main.c:513
#11 0x0000555557771fba in execute_cmdargs (cmdarg_vec=0x7fffffffd570, file_type=CMDARG_FILE, cmd_type=CMDARG_COMMAND, ret=0x7fffffffd230) at /home/simark/src/binutils-gdb/gdb/main.c:608
#12 0x00005555577755ac in captured_main_1 (context=0x7fffffffda10) at /home/simark/src/binutils-gdb/gdb/main.c:1299
#13 0x0000555557775c2d in captured_main (data=0x7fffffffda10) at /home/simark/src/binutils-gdb/gdb/main.c:1320
#14 0x0000555557775cc2 in gdb_main (args=0x7fffffffda10) at /home/simark/src/binutils-gdb/gdb/main.c:1345
#15 0x00005555568bdcbe in main (argc=10, argv=0x7fffffffdba8) at /home/simark/src/binutils-gdb/gdb/gdb.c:32
Here, target_auxv_search is called on the inferior's target stack. The
target stack only contains the exec target, so the query returns empty
auxv data. This gets cached for that inferior in `auxv_inferior_data`.
In its constructor (before it is pushed to the inferior's target stack),
the core_target needs to identify the right target description from the
core, and for that asks the gdbarch to read a target description from
the core file. Because some implementations of
gdbarch_core_read_description (such as AArch64's) need to read auxv data
from the core in order to determine the right target description, the
core_target passes a pointer to itself, allowing implementations to call
target_auxv_search it. However, because we have previously cached
(empty) auxv data for that inferior, target_auxv_search searched that
cached (empty) auxv data, not auxv data read from the core. Remember
that this data was obtained by reading auxv on the inferior's target
stack, which only contained an exec target.
The problem I see is that while target_auxv_search offers the
flexibility of reading from an arbitrary (passed as an argument) target,
the caching doesn't do the distinction of which target is being queried,
and where the cached data came from. So, you could read auxv from a
target A, it gets cached, then you try to read auxv from a target B, and
it returns the cached data from target A. That sounds wrong. In our
case, we expect to read different auxv data from the core target than
what we have read from the target stack earlier, so it doesn't make
sense to hit the cache in this case.
To fix this, I propose splitting the code paths that read auxv data from
an inferior's target stack and those that read from a passed-in target.
The code path that reads from the target stack will keep caching,
whereas the one that reads from a passed-in target won't. And since,
searching in auxv data is independent from where this data came from,
split the "read" part from the "search" part.
From what I understand, auxv caching was introduced mostly to reduce
latency on remote connections, when doing many queries. With the change
I propose, only the queries done while constructing the core_target
end up not using cached auxv data. This is fine, because there are just
a handful of queries max, done at this point, and reading core files is
local.
The changes to auxv functions are:
- Introduce 2 target_read_auxv functions. One reads from an explicit
target_ops and doesn't do caching (to be used in
gdbarch_core_read_description context). The other takes no argument,
reads from the current inferior's target stack (it looks just like a
standard target function wrapper) and does caching.
The first target_read_auxv actually replaces get_auxv_inferior_data,
since it became a trivial wrapper around it.
- Change the existing target_auxv_search to not read auxv data from the
target, but to accept it as a parameter (a gdb::byte_vector). This
function doesn't care where the data came from, it just searches in
it. It still needs to take a target_ops and gdbarch to know how to
parse auxv entries.
- Add a convenience target_auxv_search overload that reads auxv
data from the inferior's target stack and searches in it. This
overload is useful to replace the exist target_auxv_search calls that
passed the `current_inferior ()->top_target ()` target and keep the
call sites short.
- Modify parse_auxv to accept a target_ops and gdbarch to use for
parsing entries. Not strictly related to the rest of this change,
but it seems like a good change in the context.
Changes in architecture-specific files (tdep and nat):
- In linux-tdep, linux_get_hwcap and linux_get_hwcap2 get split in two,
similar to target_auxv_search. One version receives auxv data,
target and arch as parameters. The other gets everything from the
current inferior. The latter is for convenience, to avoid making
call sites too ugly.
- Call sites of linux_get_hwcap and linux_get_hwcap2 are adjusted to
use either of the new versions. The call sites in
gdbarch_core_read_description context explicitly read auxv data from
the passed-in target and call the linux_get_hwcap{,2} function with
parameters. Other call sites use the versions without parameters.
- Same idea for arm_fbsd_read_description_auxv.
- Call sites of target_auxv_search that passed
`current_inferior ()->top_target ()` are changed to use the
target_auxv_search overload that works in the current inferior.
Reviewed-By: John Baldwin <jhb@FreeBSD.org>
Reviewed-By: Luis Machado <luis.machado@arm.com>
Change-Id: Ib775a220cf1e76443fb7da2fdff8fc631128fe66
This changes GDB to use frame_info_ptr instead of frame_info *
The substitution was done with multiple sequential `sed` commands:
sed 's/^struct frame_info;/class frame_info_ptr;/'
sed 's/struct frame_info \*/frame_info_ptr /g' - which left some
issues in a few files, that were manually fixed.
sed 's/\<frame_info \*/frame_info_ptr /g'
sed 's/frame_info_ptr $/frame_info_ptr/g' - used to remove whitespace
problems.
The changed files were then manually checked and some 'sed' changes
undone, some constructors and some gets were added, according to what
made sense, and what Tromey originally did
Co-Authored-By: Bruno Larsen <blarsen@redhat.com>
Approved-by: Tom Tomey <tom@tromey.com>
This changes some target_so_ops instances to be const. This makes
their use a little more obvious (they can't be mutated) and also
allows for the removal of some initialization code.
This changs solib_ops to be an ordinary gdbarch value and updates all
the uses. This removes a longstanding FIXME and makes the code
somewhat cleaner as well.
gdbarch implements its own registry-like approach. This patch changes
it to instead use registry.h. It's a rather large patch but largely
uninteresting -- it's mostly a straightforward conversion from the old
approach to the new one.
The main benefit of this change is that it introduces type safety to
the gdbarch registry. It also removes a bunch of code.
One possible drawback is that, previously, the gdbarch registry
differentiated between pre- and post-initialization setup. This
doesn't seem very important to me, though.
This changes struct objfile to use a gdb_bfd_ref_ptr. In addition to
removing some manual memory management, this fixes a use-after-free
that was introduced by the registry rewrite series. The issue there
was that, in some cases, registry shutdown could refer to memory that
had already been freed. This help fix the bug by delaying the
destruction of the BFD reference (and thus the per-bfd object) until
after the registry has been shut down.
This rewrites registry.h, removing all the macros and replacing it
with relatively ordinary template classes. The result is less code
than the previous setup. It replaces large macros with a relatively
straightforward C++ class, and now manages its own cleanup.
The existing type-safe "key" class is replaced with the equivalent
template class. This approach ended up requiring relatively few
changes to the users of the registry code in gdb -- code using the key
system just required a small change to the key's declaration.
All existing users of the old C-like API are now converted to use the
type-safe API. This mostly involved changing explicit deletion
functions to be an operator() in a deleter class.
The old "save/free" two-phase process is removed, and replaced with a
single "free" phase. No existing code used both phases.
The old "free" callbacks took a parameter for the enclosing container
object. However, this wasn't truly needed and is removed here as
well.
A rather straightforward patch to change an instance of callback +
void pointer to gdb::function_view, allowing pasing lambdas that
capture, and eliminating the need for the untyped pointer.
Change-Id: I73ed644e7849945265a2c763f79f5456695b0037
Commit df22c1e5d5 handled the case that
a separate debug file was passed as the objfile for a shared library
to svr4_fetch_objfile_link_map. However, a separate debug file can
also be passed for TLS variables in the main executable. In addition,
frv_fetch_objfile_link_map also expects to be passed the original
objfile rather than a separate debug file, so pull the code to resolve
a separate debug file to the main objfile up into
target_translate_tls_address.
Now that filtered and unfiltered output can be treated identically, we
can unify the printf family of functions. This is done under the name
"gdb_printf". Most of this patch was written by script.
A number of spots call printf_unfiltered only because they are in code
that should not be interrupted by the pager. However, I believe these
cases are all handled by infrun's blanket ban on paging, and so can be
converted to the default (_filtered) API.
After this patch, I think all the remaining _unfiltered calls are ones
that really ought to be. A few -- namely in complete_command -- could
be replaced by a scoped assignment to pagination_enabled, but for the
remainder, the code seems simple enough like this.
This commit brings all the changes made by running gdb/copyright.py
as per GDB's Start of New Year Procedure.
For the avoidance of doubt, all changes in this commits were
performed by the script.
scan_dyntag is unnecessarily duplicated in solib-svr4.c and solib-dsbt.c.
Move this function to solib.c and rename it to gdb_bfd_scan_elf_dyntag.
Also add it to solib.h so it is included in both solib-svr4 and solib-dsbt.
Now that we have range functions that let us use ranged for loops, we
can remove iterate_over_breakpoints in favor of those, which are easier
to read and write. This requires exposing the declaration of
all_breakpoints and all_breakpoints_safe in breakpoint.h, as well as the
supporting types.
Change some users of iterate_over_breakpoints to use all_breakpoints,
when they don't need to delete the breakpoint, and all_breakpoints_safe
otherwise.
gdb/ChangeLog:
* breakpoint.h (iterate_over_breakpoints): Remove. Update
callers to use all_breakpoints or all_breakpoints_safe.
(breakpoint_range, all_breakpoints, breakpoint_safe_range,
all_breakpoints_safe): Move here.
* breakpoint.c (all_breakpoints, all_breakpoints_safe): Make
non-static.
(iterate_over_breakpoints): Remove.
* python/py-finishbreakpoint.c (bpfinishpy_detect_out_scope_cb):
Return void.
* python/py-breakpoint.c (build_bp_list): Add comment, reverse
return value logic.
* guile/scm-breakpoint.c (bpscm_build_bp_list): Return void.
Change-Id: Idde764a1f577de0423e4f2444a7d5cdb01ba5e48
Add the breakpoint::locations method, which returns a range that can be
used to iterate over a breakpoint's locations. This shortens
for (bp_location *loc = b->loc; loc != nullptr; loc = loc->next)
into
for (bp_location *loc : b->locations ())
Change all the places that I found that could use it.
gdb/ChangeLog:
* breakpoint.h (bp_locations_range): New.
(struct breakpoint) <locations>: New. Use where possible.
Change-Id: I1ba2f7d93d57e544e1f8609124587dcf2e1da037
Give a name to each observer, this will help produce more meaningful
debug message.
gdbsupport/ChangeLog:
* observable.h (class observable) <struct observer> <observer>:
Add name parameter.
<name>: New field.
<attach>: Add name parameter, update all callers.
Change-Id: Ie0cc4664925215b8d2b09e026011b7803549fba0
The current_top_target function is a hidden dependency on the current
inferior. Since I'd like to slowly move towards reducing our dependency
on the global current state, remove this function and make callers use
current_inferior ()->top_target ()
There is no expected change in behavior, but this one step towards
making those callers use the inferior from their context, rather than
refer to the global current inferior.
gdb/ChangeLog:
* target.h (current_top_target): Remove, make callers use the
current inferior instead.
* target.c (current_top_target): Remove.
Change-Id: Iccd457036f84466cdaa3865aa3f9339a24ea001d
Following on from earlier commits which made access to the
target_sections table more 'const', this commit makes the table
private within the program_space class and provides member functions
to access the table.
Ideally I would have liked for the new target_sections member
function (on program_space) to return a 'const' reference to the table
within the program_space. Unfortunately, there are two places in
solib-*.c, where code outside of the program_space class modifies the
target_sections table, and so to support this we need to return a
non-const reference.
There should be no user visible changes after this commit.
gdb/ChangeLog:
* exec.c (exec_target::close): Call new clear_target_sections
function.
(program_space::add_target_sections): Update name of member
variable.
(program_space::foreach_target_section): New function.
(program_space::add_target_sections): Update name of member
variable.
(program_space::remove_target_sections): Likewise.
(exec_one_fork): Use new target_sections member function.
(exec_target::get_section_table): Likewise.
(exec_target::files_info): Likewise.
(set_section_command): Use new foreach_target_section member
function.
(exec_set_section_address): Likewise.
(exec_target::has_memory): Use new target_sections member
function.
* progspace.h (program_space::clear_target_sections): New member
function.
(program_space::target_sections): Rename member variable to
m_target_sections, replace with a new member function.
(program_space::foreach_target_section): Declare new member
function.
(program_space::m_target_sections): New member variable.
* solib-dsbt.c (scan_dyntag): Use new member function.
* solib-svr4.c (scan_dyntag): Likewise.
The code to access the target section table can be made more const, so
lets do that. There should be no user visible changes after this
commit.
gdb/ChangeLog:
* gdb/bfd-target.c (class target_bfd) <get_section_table>: Make
return type const.
* gdb/exec.c (struct exec_target) <get_section_table>: Likewise.
(section_table_read_available_memory): Make local const.
(exec_target::xfer_partial): Make local const.
(print_section_info): Make parameter const.
* gdb/exec.h (print_section_info): Likewise.
* gdb/ppc64-tdep.c (ppc64_convert_from_func_ptr_addr): Make local
const.
* gdb/record-btrace.c (record_btrace_target::xfer_partial):
Likewise.
* gdb/remote.c (remote_target::remote_xfer_live_readonly_partial):
Likewise.
* gdb/s390-tdep.c (s390_load): Likewise.
* gdb/solib-dsbt.c (scan_dyntag): Likewise.
* gdb/solib-svr4.c (scan_dyntag): Likewise.
* gdb/target-debug.h (target_debug_print_target_section_table_p):
Rename to...
(target_debug_print_const_target_section_table_p): ...this.
* gdb/target-delegates.c: Regenerate.
* gdb/target.c (target_get_section_table): Make return type const.
(target_section_by_addr): Likewise. Also make some locals const.
(memory_xfer_partial_1): Make some locals const.
* gdb/target.h (struct target_ops) <get_section_table>: Make
return type const.
(target_section_by_addr): Likewise.
(target_get_section_table): Likewise.
While looking at Andrew's recent target sections series, I saw that
target_bfd_reopen took a "bfd *", leading to a call to new_reference.
However, because the only caller of target_bfd_reopen is already using
gdb_bfd_ref_ptr, this code can be simplified and the explicit call to
new_reference can be removed.
gdb/ChangeLog
2021-02-22 Tom Tromey <tromey@adacore.com>
* solib-svr4.c (enable_break): Update.
* bfd-target.c (class target_bfd) <target_bfd>: Change parameter
type.
(target_bfd_reopen): Change parameter type.
* bfd-target.h (target_bfd_reopen): Change parameter type.
This commits the result of running gdb/copyright.py as per our Start
of New Year procedure...
gdb/ChangeLog
Update copyright year range in copyright header of all GDB files.
Because target_section_table only holds a vector, and because it is
used in an "open" way, this patch makes it just be an alias for the
std::vector specialization. This makes the code less wordy. If we do
ever want to add more specialized behavior to this type, it's simple
enough to convert it back to a struct with the few needed methods
implied by this change.
gdb/ChangeLog
2020-10-12 Tom Tromey <tom@tromey.com>
* target.h (struct target_ops) <get_section_table>: Update.
(target_get_section_table): Update.
* target.c (target_get_section_table, target_section_by_addr)
(memory_xfer_partial_1): Update.
* target-section.h (target_section_table): Now an alias.
* target-delegates.c: Rebuild.
* target-debug.h (target_debug_print_target_section_table_p):
Rename from target_debug_print_struct_target_section_table_p.
* symfile.c (build_section_addr_info_from_section_table): Update.
* solib.c (solib_map_sections, solib_contains_address_p): Update.
* solib-svr4.c (scan_dyntag): Update.
* solib-dsbt.c (scan_dyntag): Update.
* remote.c (remote_target::remote_xfer_live_readonly_partial):
Update.
* record-full.c (record_full_core_target::xfer_partial): Update.
* progspace.h (struct program_space) <target_sections>: Update.
* exec.h (print_section_info): Update.
* exec.c (exec_target::close, build_section_table)
(add_target_sections, add_target_sections_of_objfile)
(remove_target_sections, exec_on_vfork)
(section_table_available_memory)
(section_table_xfer_memory_partial)
(exec_target::get_section_table, exec_target::xfer_partial)
(print_section_info, set_section_command)
(exec_set_section_address, exec_target::has_memory): Update.
* corelow.c (core_target::build_file_mappings)
(core_target::xfer_partial, core_target::info_proc_mappings)
(core_target::info_proc_mappings): Update.
* bfd-target.c (class target_bfd): Update
This changes target_section_table to wrap a std::vector. This
simplifies some code, and also enables the simplifications coming in
the subsequent patches.
Note that for solib, I chose to have it use a pointer to a
target_section_table. This is more convoluted than would be ideal,
but I didn't want to convert solib to new/delete as a prerequisite for
this series.
gdb/ChangeLog
2020-10-12 Tom Tromey <tom@tromey.com>
* target.c (target_section_by_addr, memory_xfer_partial_1):
Update.
* target-section.h (struct target_section_table): Use
std::vector.
* symfile.h (build_section_addr_info_from_section_table): Take a
target_section_table.
* symfile.c (build_section_addr_info_from_section_table): Take a
target_section_table.
* solist.h (struct so_list) <sections>: Change type.
<sections_end>: Remove.
* solib.c (solib_map_sections, clear_so, solib_read_symbols)
(solib_contains_address_p): Update.
* solib-svr4.c (scan_dyntag): Update.
* solib-dsbt.c (scan_dyntag): Update.
* remote.c (remote_target::remote_xfer_live_readonly_partial):
Update.
* record-full.c (record_full_core_start, record_full_core_end):
Remove.
(record_full_core_sections): New global.
(record_full_core_open_1, record_full_core_target::xfer_partial):
Update.
* exec.h (build_section_table, section_table_xfer_memory_partial)
(add_target_sections): Take a target_section_table.
* exec.c (exec_file_attach, clear_section_table): Update.
(resize_section_table): Remove.
(build_section_table, add_target_sections): Take a
target_section_table.
(add_target_sections_of_objfile, remove_target_sections)
(exec_on_vfork): Update.
(section_table_available_memory): Take a target_section_table.
(section_table_read_available_memory): Update.
(section_table_xfer_memory_partial): Take a target_section_table.
(print_section_info, set_section_command)
(exec_set_section_address, exec_target::has_memory): Update.
* corelow.c (class core_target) <m_core_section_table,
m_core_file_mappings>: Remove braces.
<~core_target>: Remove.
(core_target::core_target): Update.
(core_target::~core_target): Remove.
(core_target::build_file_mappings)
(core_target::xfer_memory_via_mappings)
(core_target::xfer_partial, core_target::info_proc_mappings):
Update.
* bfd-target.c (target_bfd::xfer_partial): Update.
(target_bfd::target_bfd): Update.
(target_bfd::~target_bfd): Remove.
This simplifies the target_read_string API a bit.
Note that some code was using safe_strerror on the error codes
returned by target_read_string. It seems to me that this is incorrect
(if it was ever correct, it must have been quite a long time ago).
gdb/ChangeLog
2020-06-15 Tom Tromey <tromey@adacore.com>
* windows-nat.c (windows_nat::handle_output_debug_string):
Update.
(windows_nat::handle_ms_vc_exception): Update.
* target.h (target_read_string): Change API.
* target.c (target_read_string): Change API.
* solib-svr4.c (open_symbol_file_object, svr4_read_so_list):
Update.
* solib-frv.c (frv_current_sos): Update.
* solib-dsbt.c (dsbt_current_sos): Update.
* solib-darwin.c (darwin_current_sos): Update.
* linux-thread-db.c (inferior_has_bug): Update.
* expprint.c (print_subexp_standard): Update.
* ada-lang.c (ada_main_name, ada_tag_name_from_tsd)
(ada_exception_message_1): Update.
This patch started as an attempt to replace ALL_SO_LIBS with an
ordinary C++ iterator. However, then I tripped over the so_list_head
define again, and decided to remove it as well.
gdb/ChangeLog
2020-05-08 Tom Tromey <tom@tromey.com>
* mi/mi-cmd-file.c (mi_cmd_file_list_shared_libraries): Update.
* solib-svr4.c (svr4_fetch_objfile_link_map): Update.
(enable_break): Update.
* solib-frv.c (frv_fdpic_find_global_pointer): Update.
(frv_fdpic_find_canonical_descriptor): Update.
(frv_fetch_objfile_link_map): Update.
* progspace.c (program_space::free_all_objfiles): Update.
(program_space::solibs): New method.
* progspace.h (struct program_space) <solibs>: New method.
* solist.h (master_so_list): Don't declare.
(ALL_SO_LIBS): Remove.
* solib.h (so_list_head): Remove.
(update_solib_list): Update comment.
* solib.c (master_so_list): Remove.
(solib_used, update_solib_list, solib_add)
(info_sharedlibrary_command, clear_solib)
(reload_shared_libraries_1, remove_user_added_objfile): Update.
The pattern
objfile->section_offsets[SECT_OFF_TEXT (objfile)]
... appears very often, to get the offset of the text section of an
objfile. I thought it would be more readable to write it as:
objfile->text_section_offset ()
... so I added this method and used it where possible. I also added
data_section_offset, although it is not used as much.
gdb/ChangeLog:
* objfiles.h (ALL_OBJFILE_OSECTIONS): Move up.
(SECT_OFF_DATA): Likewise.
(SECT_OFF_RODATA): Likewise.
(SECT_OFF_TEXT): Likewise.
(SECT_OFF_BSS): Likewise.
(struct objfile) <text_section_offset, data_section_offset>: New
methods.
* amd64-windows-tdep.c (amd64_windows_find_unwind_info): Use
objfile::text_section_offset.
* coff-pe-read.c (add_pe_forwarded_sym): Likewise.
* coffread.c (coff_symtab_read): Likewise.
(enter_linenos): Likewise.
(process_coff_symbol): Likewise.
* ctfread.c (get_objfile_text_range): Likewise.
* dtrace-probe.c (dtrace_probe::get_relocated_address):
Use objfile::data_section_offset.
* dwarf2-frame.c (execute_cfa_program): Use
objfile::text_section_offset.
(dwarf2_frame_find_fde): Likewise.
* dwarf2read.c (create_addrmap_from_index): Likewise.
(create_addrmap_from_aranges): Likewise.
(dw2_find_pc_sect_compunit_symtab): Likewise.
(process_psymtab_comp_unit_reader): Likewise.
(add_partial_symbol): Likewise.
(add_partial_subprogram): Likewise.
(process_full_comp_unit): Likewise.
(read_file_scope): Likewise.
(read_func_scope): Likewise.
(read_lexical_block_scope): Likewise.
(read_call_site_scope): Likewise.
(dwarf2_rnglists_process): Likewise.
(dwarf2_ranges_process): Likewise.
(dwarf2_ranges_read): Likewise.
(dwarf_decode_lines_1): Likewise.
(new_symbol): Likewise.
(dwarf2_fetch_die_loc_sect_off): Likewise.
(dwarf2_per_cu_text_offset): Likewise.
* hppa-bsd-tdep.c (hppabsd_find_global_pointer): Likewise.
* hppa-tdep.c (read_unwind_info): Likewise.
* ia64-tdep.c (ia64_find_unwind_table): Likewise.
* psympriv.h (struct partial_symtab): Likewise.
* psymtab.c (find_pc_sect_psymtab): Likewise.
* solib-svr4.c (enable_break): Likewise.
* stap-probe.c (relocate_address): Use
objfile::data_section_offset.
* xcoffread.c (enter_line_range): Use
objfile::text_section_offset.
(read_xcoff_symtab): Likewise.
This commit adds multi-target support to GDB. What this means is that
with this commit, GDB can now be connected to different targets at the
same time. E.g., you can debug a live native process and a core dump
at the same time, connect to multiple gdbservers, etc.
Actually, the word "target" is overloaded in gdb. We already have a
target stack, with pushes several target_ops instances on top of one
another. We also have "info target" already, which means something
completely different to what this patch does.
So from here on, I'll be using the "target connections" term, to mean
an open process_stratum target, pushed on a target stack. This patch
makes gdb have multiple target stacks, and multiple process_stratum
targets open simultaneously. The user-visible changes / commands will
also use this terminology, but of course it's all open to debate.
User-interface-wise, not that much changes. The main difference is
that each inferior may have its own target connection.
A target connection (e.g., a target extended-remote connection) may
support debugging multiple processes, just as before.
Say you're debugging against gdbserver in extended-remote mode, and
you do "add-inferior" to prepare to spawn a new process, like:
(gdb) target extended-remote :9999
...
(gdb) start
...
(gdb) add-inferior
Added inferior 2
(gdb) inferior 2
[Switching to inferior 2 [<null>] (<noexec>)]
(gdb) file a.out
...
(gdb) start
...
At this point, you have two inferiors connected to the same gdbserver.
With this commit, GDB will maintain a target stack per inferior,
instead of a global target stack.
To preserve the behavior above, by default, "add-inferior" makes the
new inferior inherit a copy of the target stack of the current
inferior. Same across a fork - the child inherits a copy of the
target stack of the parent. While the target stacks are copied, the
targets themselves are not. Instead, target_ops is made a
refcounted_object, which means that target_ops instances are
refcounted, which each inferior counting for a reference.
What if you want to create an inferior and connect it to some _other_
target? For that, this commit introduces a new "add-inferior
-no-connection" option that makes the new inferior not share the
current inferior's target. So you could do:
(gdb) target extended-remote :9999
Remote debugging using :9999
...
(gdb) add-inferior -no-connection
[New inferior 2]
Added inferior 2
(gdb) inferior 2
[Switching to inferior 2 [<null>] (<noexec>)]
(gdb) info inferiors
Num Description Executable
1 process 18401 target:/home/pedro/tmp/main
* 2 <null>
(gdb) tar extended-remote :10000
Remote debugging using :10000
...
(gdb) info inferiors
Num Description Executable
1 process 18401 target:/home/pedro/tmp/main
* 2 process 18450 target:/home/pedro/tmp/main
(gdb)
A following patch will extended "info inferiors" to include a column
indicating which connection an inferior is bound to, along with a
couple other UI tweaks.
Other than that, debugging is the same as before. Users interact with
inferiors and threads as before. The only difference is that
inferiors may be bound to processes running in different machines.
That's pretty much all there is to it in terms of noticeable UI
changes.
On to implementation.
Since we can be connected to different systems at the same time, a
ptid_t is no longer a unique identifier. Instead a thread can be
identified by a pair of ptid_t and 'process_stratum_target *', the
later being the instance of the process_stratum target that owns the
process/thread. Note that process_stratum_target inherits from
target_ops, and all process_stratum targets inherit from
process_stratum_target. In earlier patches, many places in gdb were
converted to refer to threads by thread_info pointer instead of
ptid_t, but there are still places in gdb where we start with a
pid/tid and need to find the corresponding inferior or thread_info
objects. So you'll see in the patch many places adding a
process_stratum_target parameter to functions that used to take only a
ptid_t.
Since each inferior has its own target stack now, we can always find
the process_stratum target for an inferior. That is done via a
inf->process_target() convenience method.
Since each inferior has its own target stack, we need to handle the
"beneath" calls when servicing target calls. The solution I settled
with is just to make sure to switch the current inferior to the
inferior you want before making a target call. Not relying on global
context is just not feasible in current GDB. Fortunately, there
aren't that many places that need to do that, because generally most
code that calls target methods already has the current context
pointing to the right inferior/thread. Note, to emphasize -- there's
no method to "switch to this target stack". Instead, you switch the
current inferior, and that implicitly switches the target stack.
In some spots, we need to iterate over all inferiors so that we reach
all target stacks.
Native targets are still singletons. There's always only a single
instance of such targets.
Remote targets however, we'll have one instance per remote connection.
The exec target is still a singleton. There's only one instance. I
did not see the point of instanciating more than one exec_target
object.
After vfork, we need to make sure to push the exec target on the new
inferior. See exec_on_vfork.
For type safety, functions that need a {target, ptid} pair to identify
a thread, take a process_stratum_target pointer for target parameter
instead of target_ops *. Some shared code in gdb/nat/ also need to
gain a target pointer parameter. This poses an issue, since gdbserver
doesn't have process_stratum_target, only target_ops. To fix this,
this commit renames gdbserver's target_ops to process_stratum_target.
I think this makes sense. There's no concept of target stack in
gdbserver, and gdbserver's target_ops really implements a
process_stratum-like target.
The thread and inferior iterator functions also gain
process_stratum_target parameters. These are used to be able to
iterate over threads and inferiors of a given target. Following usual
conventions, if the target pointer is null, then we iterate over
threads and inferiors of all targets.
I tried converting "add-inferior" to the gdb::option framework, as a
preparatory patch, but that stumbled on the fact that gdb::option does
not support file options yet, for "add-inferior -exec". I have a WIP
patchset that adds that, but it's not a trivial patch, mainly due to
need to integrate readline's filename completion, so I deferred that
to some other time.
In infrun.c/infcmd.c, the main change is that we need to poll events
out of all targets. See do_target_wait. Right after collecting an
event, we switch the current inferior to an inferior bound to the
target that reported the event, so that target methods can be used
while handling the event. This makes most of the code transparent to
multi-targets. See fetch_inferior_event.
infrun.c:stop_all_threads is interesting -- in this function we need
to stop all threads of all targets. What the function does is send an
asynchronous stop request to all threads, and then synchronously waits
for events, with target_wait, rinse repeat, until all it finds are
stopped threads. Now that we have multiple targets, it's not
efficient to synchronously block in target_wait waiting for events out
of one target. Instead, we implement a mini event loop, with
interruptible_select, select'ing on one file descriptor per target.
For this to work, we need to be able to ask the target for a waitable
file descriptor. Such file descriptors already exist, they are the
descriptors registered in the main event loop with add_file_handler,
inside the target_async implementations. This commit adds a new
target_async_wait_fd target method that just returns the file
descriptor in question. See wait_one / stop_all_threads in infrun.c.
The 'threads_executing' global is made a per-target variable. Since
it is only relevant to process_stratum_target targets, this is where
it is put, instead of in target_ops.
You'll notice that remote.c includes some FIXME notes. These refer to
the fact that the global arrays that hold data for the remote packets
supported are still globals. For example, if we connect to two
different servers/stubs, then each might support different remote
protocol features. They might even be different architectures, like
e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a
host/controller scenario as a single program. That isn't going to
work correctly today, because of said globals. I'm leaving fixing
that for another pass, since it does not appear to be trivial, and I'd
rather land the base work first. It's already useful to be able to
debug multiple instances of the same server (e.g., a distributed
cluster, where you have full control over the servers installed), so I
think as is it's already reasonable incremental progress.
Current limitations:
- You can only resume more that one target at the same time if all
targets support asynchronous debugging, and support non-stop mode.
It should be possible to support mixed all-stop + non-stop
backends, but that is left for another time. This means that
currently in order to do multi-target with gdbserver you need to
issue "maint set target-non-stop on". I would like to make that
mode be the default, but we're not there yet. Note that I'm
talking about how the target backend works, only. User-visible
all-stop mode works just fine.
- As explained above, connecting to different remote servers at the
same time is likely to produce bad results if they don't support the
exact set of RSP features.
FreeBSD updates courtesy of John Baldwin.
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
John Baldwin <jhb@FreeBSD.org>
* aarch64-linux-nat.c
(aarch64_linux_nat_target::thread_architecture): Adjust.
* ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call.
(task_command_1): Likewise.
* aix-thread.c (sync_threadlists, aix_thread_target::resume)
(aix_thread_target::wait, aix_thread_target::fetch_registers)
(aix_thread_target::store_registers)
(aix_thread_target::thread_alive): Adjust.
* amd64-fbsd-tdep.c: Include "inferior.h".
(amd64fbsd_get_thread_local_address): Pass down target.
* amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle
thread's gdbarch instead of target_gdbarch.
* break-catch-sig.c (signal_catchpoint_print_it): Adjust call to
get_last_target_status.
* break-catch-syscall.c (print_it_catch_syscall): Likewise.
* breakpoint.c (breakpoints_should_be_inserted_now): Consider all
inferiors.
(update_inserted_breakpoint_locations): Skip if inferiors with no
execution.
(update_global_location_list): When handling moribund locations,
find representative inferior for location's pspace, and use thread
count of its process_stratum target.
* bsd-kvm.c (bsd_kvm_target_open): Pass target down.
* bsd-uthread.c (bsd_uthread_target::wait): Use
as_process_stratum_target and adjust thread_change_ptid and
add_thread calls.
(bsd_uthread_target::update_thread_list): Use
as_process_stratum_target and adjust find_thread_ptid,
thread_change_ptid and add_thread calls.
* btrace.c (maint_btrace_packet_history_cmd): Adjust
find_thread_ptid call.
* corelow.c (add_to_thread_list): Adjust add_thread call.
(core_target_open): Adjust add_thread_silent and thread_count
calls.
(core_target::pid_to_str): Adjust find_inferior_ptid call.
* ctf.c (ctf_target_open): Adjust add_thread_silent call.
* event-top.c (async_disconnect): Pop targets from all inferiors.
* exec.c (add_target_sections): Push exec target on all inferiors
sharing the program space.
(remove_target_sections): Remove the exec target from all
inferiors sharing the program space.
(exec_on_vfork): New.
* exec.h (exec_on_vfork): Declare.
* fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter.
Pass it down.
(fbsd_nat_target::update_thread_list): Adjust.
(fbsd_nat_target::resume): Adjust.
(fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it
down.
(fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust.
* fbsd-tdep.c (fbsd_corefile_thread): Adjust
get_thread_arch_regcache call.
* fork-child.c (gdb_startup_inferior): Pass target down to
startup_inferior and set_executing.
* gdbthread.h (struct process_stratum_target): Forward declare.
(add_thread, add_thread_silent, add_thread_with_info)
(in_thread_list): Add process_stratum_target parameter.
(find_thread_ptid(inferior*, ptid_t)): New overload.
(find_thread_ptid, thread_change_ptid): Add process_stratum_target
parameter.
(all_threads()): Delete overload.
(all_threads, all_non_exited_threads): Add process_stratum_target
parameter.
(all_threads_safe): Use brace initialization.
(thread_count): Add process_stratum_target parameter.
(set_resumed, set_running, set_stop_requested, set_executing)
(threads_are_executing, finish_thread_state): Add
process_stratum_target parameter.
(switch_to_thread): Use is_current_thread.
* i386-fbsd-tdep.c: Include "inferior.h".
(i386fbsd_get_thread_local_address): Pass down target.
* i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust.
* inf-child.c (inf_child_target::maybe_unpush_target): Remove
have_inferiors check.
* inf-ptrace.c (inf_ptrace_target::create_inferior)
(inf_ptrace_target::attach): Adjust.
* infcall.c (run_inferior_call): Adjust.
* infcmd.c (run_command_1): Pass target to
scoped_finish_thread_state.
(proceed_thread_callback): Skip inferiors with no execution.
(continue_command): Rename 'all_threads' local to avoid hiding
'all_threads' function. Adjust get_last_target_status call.
(prepare_one_step): Adjust set_running call.
(signal_command): Use user_visible_resume_target. Compare thread
pointers instead of inferior_ptid.
(info_program_command): Adjust to pass down target.
(attach_command): Mark target's 'thread_executing' flag.
(stop_current_target_threads_ns): New, factored out from ...
(interrupt_target_1): ... this. Switch inferior before making
target calls.
* inferior-iter.h
(struct all_inferiors_iterator, struct all_inferiors_range)
(struct all_inferiors_safe_range)
(struct all_non_exited_inferiors_range): Filter on
process_stratum_target too. Remove explicit.
* inferior.c (inferior::inferior): Push dummy target on target
stack.
(find_inferior_pid, find_inferior_ptid, number_of_live_inferiors):
Add process_stratum_target parameter, and pass it down.
(have_live_inferiors): Adjust.
(switch_to_inferior_and_push_target): New.
(add_inferior_command, clone_inferior_command): Handle
"-no-connection" parameter. Use
switch_to_inferior_and_push_target.
(_initialize_inferior): Mention "-no-connection" option in
the help of "add-inferior" and "clone-inferior" commands.
* inferior.h: Include "process-stratum-target.h".
(interrupt_target_1): Use bool.
(struct inferior) <push_target, unpush_target, target_is_pushed,
find_target_beneath, top_target, process_target, target_at,
m_stack>: New.
(discard_all_inferiors): Delete.
(find_inferior_pid, find_inferior_ptid, number_of_live_inferiors)
(all_inferiors, all_non_exited_inferiors): Add
process_stratum_target parameter.
* infrun.c: Include "gdb_select.h" and <unordered_map>.
(target_last_proc_target): New global.
(follow_fork_inferior): Push target on new inferior. Pass target
to add_thread_silent. Call exec_on_vfork. Handle target's
reference count.
(follow_fork): Adjust get_last_target_status call. Also consider
target.
(follow_exec): Push target on new inferior.
(struct execution_control_state) <target>: New field.
(user_visible_resume_target): New.
(do_target_resume): Call target_async.
(resume_1): Set target's threads_executing flag. Consider resume
target.
(commit_resume_all_targets): New.
(proceed): Also consider resume target. Skip threads of inferiors
with no execution. Commit resumtion in all targets.
(start_remote): Pass current inferior to wait_for_inferior.
(infrun_thread_stop_requested): Consider target as well. Pass
thread_info pointer to clear_inline_frame_state instead of ptid.
(infrun_thread_thread_exit): Consider target as well.
(random_pending_event_thread): New inferior parameter. Use it.
(do_target_wait): Rename to ...
(do_target_wait_1): ... this. Add inferior parameter, and pass it
down.
(threads_are_resumed_pending_p, do_target_wait): New.
(prepare_for_detach): Adjust calls.
(wait_for_inferior): New inferior parameter. Handle it. Use
do_target_wait_1 instead of do_target_wait.
(fetch_inferior_event): Adjust. Switch to representative
inferior. Pass target down.
(set_last_target_status): Add process_stratum_target parameter.
Save target in global.
(get_last_target_status): Add process_stratum_target parameter and
handle it.
(nullify_last_target_wait_ptid): Clear 'target_last_proc_target'.
(context_switch): Check inferior_ptid == null_ptid before calling
inferior_thread().
(get_inferior_stop_soon): Pass down target.
(wait_one): Rename to ...
(poll_one_curr_target): ... this.
(struct wait_one_event): New.
(wait_one): New.
(stop_all_threads): Adjust.
(handle_no_resumed, handle_inferior_event): Adjust to consider the
event's target.
(switch_back_to_stepped_thread): Also consider target.
(print_stop_event): Update.
(normal_stop): Update. Also consider the resume target.
* infrun.h (wait_for_inferior): Remove declaration.
(user_visible_resume_target): New declaration.
(get_last_target_status, set_last_target_status): New
process_stratum_target parameter.
* inline-frame.c (clear_inline_frame_state(ptid_t)): Add
process_stratum_target parameter, and use it.
(clear_inline_frame_state (thread_info*)): New.
* inline-frame.c (clear_inline_frame_state(ptid_t)): Add
process_stratum_target parameter.
(clear_inline_frame_state (thread_info*)): Declare.
* linux-fork.c (delete_checkpoint_command): Pass target down to
find_thread_ptid.
(checkpoint_command): Adjust.
* linux-nat.c (linux_nat_target::follow_fork): Switch to thread
instead of just tweaking inferior_ptid.
(linux_nat_switch_fork): Pass target down to thread_change_ptid.
(exit_lwp): Pass target down to find_thread_ptid.
(attach_proc_task_lwp_callback): Pass target down to
add_thread/set_running/set_executing.
(linux_nat_target::attach): Pass target down to
thread_change_ptid.
(get_detach_signal): Pass target down to find_thread_ptid.
Consider last target status's target.
(linux_resume_one_lwp_throw, resume_lwp)
(linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp)
(stop_wait_callback, save_stop_reason, linux_nat_filter_event)
(linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down.
(linux_nat_target::async_wait_fd): New.
(linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass
target down.
* linux-nat.h (linux_nat_target::async_wait_fd): Declare.
* linux-tdep.c (get_thread_arch_regcache): Pass target down.
* linux-thread-db.c (struct thread_db_info::process_target): New
field.
(add_thread_db_info): Save target.
(get_thread_db_info): New process_stratum_target parameter. Also
match target.
(delete_thread_db_info): New process_stratum_target parameter.
Also match target.
(thread_from_lwp): Adjust to pass down target.
(thread_db_notice_clone): Pass down target.
(check_thread_db_callback): Pass down target.
(try_thread_db_load_1): Always push the thread_db target.
(try_thread_db_load, record_thread): Pass target down.
(thread_db_target::detach): Pass target down. Always unpush the
thread_db target.
(thread_db_target::wait, thread_db_target::mourn_inferior): Pass
target down. Always unpush the thread_db target.
(find_new_threads_callback, thread_db_find_new_threads_2)
(thread_db_target::update_thread_list): Pass target down.
(thread_db_target::pid_to_str): Pass current inferior down.
(thread_db_target::get_thread_local_address): Pass target down.
(thread_db_target::resume, maintenance_check_libthread_db): Pass
target down.
* nto-procfs.c (nto_procfs_target::update_thread_list): Adjust.
* procfs.c (procfs_target::procfs_init_inferior): Declare.
(proc_set_current_signal, do_attach, procfs_target::wait): Adjust.
(procfs_init_inferior): Rename to ...
(procfs_target::procfs_init_inferior): ... this and adjust.
(procfs_target::create_inferior, procfs_notice_thread)
(procfs_do_thread_registers): Adjust.
* ppc-fbsd-tdep.c: Include "inferior.h".
(ppcfbsd_get_thread_local_address): Pass down target.
* proc-service.c (ps_xfer_memory): Switch current inferior and
program space as well.
(get_ps_regcache): Pass target down.
* process-stratum-target.c
(process_stratum_target::thread_address_space)
(process_stratum_target::thread_architecture): Pass target down.
* process-stratum-target.h
(process_stratum_target::threads_executing): New field.
(as_process_stratum_target): New.
* ravenscar-thread.c
(ravenscar_thread_target::update_inferior_ptid): Pass target down.
(ravenscar_thread_target::wait, ravenscar_add_thread): Pass target
down.
* record-btrace.c (record_btrace_target::info_record): Adjust.
(record_btrace_target::record_method)
(record_btrace_target::record_is_replaying)
(record_btrace_target::fetch_registers)
(get_thread_current_frame_id, record_btrace_target::resume)
(record_btrace_target::wait, record_btrace_target::stop): Pass
target down.
* record-full.c (record_full_wait_1): Switch to event thread.
Pass target down.
* regcache.c (regcache::regcache)
(get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add
process_stratum_target parameter and handle it.
(current_thread_target): New global.
(get_thread_regcache): Add process_stratum_target parameter and
handle it. Switch inferior before calling target method.
(get_thread_regcache): Pass target down.
(get_thread_regcache_for_ptid): Pass target down.
(registers_changed_ptid): Add process_stratum_target parameter and
handle it.
(registers_changed_thread, registers_changed): Pass target down.
(test_get_thread_arch_aspace_regcache): New.
(current_regcache_test): Define a couple local test_target_ops
instances and use them for testing.
(readwrite_regcache): Pass process_stratum_target parameter.
(cooked_read_test, cooked_write_test): Pass mock_target down.
* regcache.h (get_thread_regcache, get_thread_arch_regcache)
(get_thread_arch_aspace_regcache): Add process_stratum_target
parameter.
(regcache::target): New method.
(regcache::regcache, regcache::get_thread_arch_aspace_regcache)
(regcache::registers_changed_ptid): Add process_stratum_target
parameter.
(regcache::m_target): New field.
(registers_changed_ptid): Add process_stratum_target parameter.
* remote.c (remote_state::supports_vCont_probed): New field.
(remote_target::async_wait_fd): New method.
(remote_unpush_and_throw): Add remote_target parameter.
(get_current_remote_target): Adjust.
(remote_target::remote_add_inferior): Push target.
(remote_target::remote_add_thread)
(remote_target::remote_notice_new_inferior)
(get_remote_thread_info): Pass target down.
(remote_target::update_thread_list): Skip threads of inferiors
bound to other targets. (remote_target::close): Don't discard
inferiors. (remote_target::add_current_inferior_and_thread)
(remote_target::process_initial_stop_replies)
(remote_target::start_remote)
(remote_target::remote_serial_quit_handler): Pass down target.
(remote_target::remote_unpush_target): New remote_target
parameter. Unpush the target from all inferiors.
(remote_target::remote_unpush_and_throw): New remote_target
parameter. Pass it down.
(remote_target::open_1): Check whether the current inferior has
execution instead of checking whether any inferior is live. Pass
target down.
(remote_target::remote_detach_1): Pass down target. Use
remote_unpush_target.
(extended_remote_target::attach): Pass down target.
(remote_target::remote_vcont_probe): Set supports_vCont_probed.
(remote_target::append_resumption): Pass down target.
(remote_target::append_pending_thread_resumptions)
(remote_target::remote_resume_with_hc, remote_target::resume)
(remote_target::commit_resume): Pass down target.
(remote_target::remote_stop_ns): Check supports_vCont_probed.
(remote_target::interrupt_query)
(remote_target::remove_new_fork_children)
(remote_target::check_pending_events_prevent_wildcard_vcont)
(remote_target::remote_parse_stop_reply)
(remote_target::process_stop_reply): Pass down target.
(first_remote_resumed_thread): New remote_target parameter. Pass
it down.
(remote_target::wait_as): Pass down target.
(unpush_and_perror): New remote_target parameter. Pass it down.
(remote_target::readchar, remote_target::remote_serial_write)
(remote_target::getpkt_or_notif_sane_1)
(remote_target::kill_new_fork_children, remote_target::kill): Pass
down target.
(remote_target::mourn_inferior): Pass down target. Use
remote_unpush_target.
(remote_target::core_of_thread)
(remote_target::remote_btrace_maybe_reopen): Pass down target.
(remote_target::pid_to_exec_file)
(remote_target::thread_handle_to_thread_info): Pass down target.
(remote_target::async_wait_fd): New.
* riscv-fbsd-tdep.c: Include "inferior.h".
(riscv_fbsd_get_thread_local_address): Pass down target.
* sol2-tdep.c (sol2_core_pid_to_str): Pass down target.
* sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs)
(ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback):
Adjust.
* solib-spu.c (spu_skip_standalone_loader): Pass down target.
* solib-svr4.c (enable_break): Pass down target.
* spu-multiarch.c (parse_spufs_run): Pass down target.
* spu-tdep.c (spu2ppu_sniffer): Pass down target.
* target-delegates.c: Regenerate.
* target.c (g_target_stack): Delete.
(current_top_target): Return the current inferior's top target.
(target_has_execution_1): Refer to the passed-in inferior's top
target.
(target_supports_terminal_ours): Check whether the initial
inferior was already created.
(decref_target): New.
(target_stack::push): Incref/decref the target.
(push_target, push_target, unpush_target): Adjust.
(target_stack::unpush): Defref target.
(target_is_pushed): Return bool. Adjust to refer to the current
inferior's target stack.
(dispose_inferior): Delete, and inline parts ...
(target_preopen): ... here. Only dispose of the current inferior.
(target_detach): Hold strong target reference while detaching.
Pass target down.
(target_thread_name): Add assertion.
(target_resume): Pass down target.
(target_ops::beneath, find_target_at): Adjust to refer to the
current inferior's target stack.
(get_dummy_target): New.
(target_pass_ctrlc): Pass the Ctrl-C to the first inferior that
has a thread running.
(initialize_targets): Rename to ...
(_initialize_target): ... this.
* target.h: Include "gdbsupport/refcounted-object.h".
(struct target_ops): Inherit refcounted_object.
(target_ops::shortname, target_ops::longname): Make const.
(target_ops::async_wait_fd): New method.
(decref_target): Declare.
(struct target_ops_ref_policy): New.
(target_ops_ref): New typedef.
(get_dummy_target): Declare function.
(target_is_pushed): Return bool.
* thread-iter.c (all_matching_threads_iterator::m_inf_matches)
(all_matching_threads_iterator::all_matching_threads_iterator):
Handle filter target.
* thread-iter.h (struct all_matching_threads_iterator, struct
all_matching_threads_range, class all_non_exited_threads_range):
Filter by target too. Remove explicit.
* thread.c (threads_executing): Delete.
(inferior_thread): Pass down current inferior.
(clear_thread_inferior_resources): Pass down thread pointer
instead of ptid_t.
(add_thread_silent, add_thread_with_info, add_thread): Add
process_stratum_target parameter. Use it for thread and inferior
searches.
(is_current_thread): New.
(thread_info::deletable): Use it.
(find_thread_ptid, thread_count, in_thread_list)
(thread_change_ptid, set_resumed, set_running): New
process_stratum_target parameter. Pass it down.
(set_executing): New process_stratum_target parameter. Pass it
down. Adjust reference to 'threads_executing'.
(threads_are_executing): New process_stratum_target parameter.
Adjust reference to 'threads_executing'.
(set_stop_requested, finish_thread_state): New
process_stratum_target parameter. Pass it down.
(switch_to_thread): Also match inferior.
(switch_to_thread): New process_stratum_target parameter. Pass it
down.
(update_threads_executing): Reimplement.
* top.c (quit_force): Pop targets from all inferior.
(gdb_init): Don't call initialize_targets.
* windows-nat.c (windows_nat_target) <get_windows_debug_event>:
Declare.
(windows_add_thread, windows_delete_thread): Adjust.
(get_windows_debug_event): Rename to ...
(windows_nat_target::get_windows_debug_event): ... this. Adjust.
* tracefile-tfile.c (tfile_target_open): Pass down target.
* gdbsupport/common-gdbthread.h (struct process_stratum_target):
Forward declare.
(switch_to_thread): Add process_stratum_target parameter.
* mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target
parameter. Use it.
(mi_on_resume): Pass target down.
* nat/fork-inferior.c (startup_inferior): Add
process_stratum_target parameter. Pass it down.
* nat/fork-inferior.h (startup_inferior): Add
process_stratum_target parameter.
* python/py-threadevent.c (py_get_event_thread): Pass target down.
gdb/gdbserver/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* fork-child.c (post_fork_inferior): Pass target down to
startup_inferior.
* inferiors.c (switch_to_thread): Add process_stratum_target
parameter.
* lynx-low.c (lynx_target_ops): Now a process_stratum_target.
* nto-low.c (nto_target_ops): Now a process_stratum_target.
* linux-low.c (linux_target_ops): Now a process_stratum_target.
* remote-utils.c (prepare_resume_reply): Pass the target to
switch_to_thread.
* target.c (the_target): Now a process_stratum_target.
(done_accessing_memory): Pass the target to switch_to_thread.
(set_target_ops): Ajust to use process_stratum_target.
* target.h (struct target_ops): Rename to ...
(struct process_stratum_target): ... this.
(the_target, set_target_ops): Adjust.
(prepare_to_access_memory): Adjust comment.
* win32-low.c (child_xfer_memory): Adjust to use
process_stratum_target.
(win32_target_ops): Now a process_stratum_target.
The SVR4 solib event handler determines whether an event is related to a
non-base link namespace by comparing the event's debug struct address
to the debug struct address of the initial program image. However, this
can fail when using LD_AUDIT as audit libraries are loaded before the
loader has initialised the initial program image's debug struct. When
the event handler fails to find the debug struct, the probe-based
debugger interface is disabled and a warning is flagged to the user.
This commit adds a fallback test to help determine whether an event is
for a foreign link namespace when the debug struct isn't available.
gdb/ChangeLog:
2019-12-15 George Barrett <bob@bob131.so>
* solib-svr4.c (svr4_handle_solib_event): Add fallback link
namespace test for when the debug struct isn't available.
- Rationale:
It is possible for compilers to indicate the desired byte order
interpretation of scalar variables using the DWARF attribute:
DW_AT_endianity
A type flagged with this variable would typically use one of:
DW_END_big
DW_END_little
which instructs the debugger what the desired byte order interpretation
of the variable should be.
The GCC compiler (as of V6) has a mechanism for setting the desired byte
ordering of the fields within a structure or union. For, example, on a
little endian target, a structure declared as:
struct big {
int v;
short a[4];
} __attribute__( ( scalar_storage_order( "big-endian" ) ) );
could be used to ensure all the structure members have a big-endian
interpretation (the compiler would automatically insert byte swap
instructions before and after respective store and load instructions).
- To reproduce
GCC V8 is required to correctly emit DW_AT_endianity DWARF attributes
in all situations when the scalar_storage_order attribute is used.
A fix for (dwarf endianity instrumentation) for GCC V6-V7 can be found
in the URL field of the following PR:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82509
- Test-case:
A new test case (testsuite/gdb.base/endianity.*) is included with this
patch.
Manual testing for mixed endianity code has also been done with GCC V8.
See:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82509#c4
- Observed vs. expected:
Without this change, using scalar_storage_order that doesn't match the
target, such as
struct otherendian
{
int v;
} __attribute__( ( scalar_storage_order( "big-endian" ) ) );
would behave like the following on a little endian target:
Breakpoint 1 at 0x401135: file endianity.c, line 41.
(gdb) run
Starting program: /home/pjoot/freeware/t/a.out
Missing separate debuginfos, use: debuginfo-install glibc-2.17-292.el7.x86_64
Breakpoint 1, main () at endianity.c:41
41 struct otherendian o = {3};
(gdb) n
43 do_nothing (&o); /* START */
(gdb) p o
$1 = {v = 50331648}
(gdb) p /x
$2 = {v = 0x3000000}
whereas with this gdb enhancement we can access the variable with the user
specified endianity:
Breakpoint 1, main () at endianity.c:41
41 struct otherendian o = {3};
(gdb) p o
$1 = {v = 0}
(gdb) n
43 do_nothing (&o); /* START */
(gdb) p o
$2 = {v = 3}
(gdb) p o.v = 4
$3 = 4
(gdb) p o.v
$4 = 4
(gdb) x/4xb &o.v
0x7fffffffd90c: 0x00 0x00 0x00 0x04
(observe that the 4 byte int variable has a big endian representation in the
hex dump.)
gdb/ChangeLog
2019-11-21 Peeter Joot <peeter.joot@lzlabs.com>
Byte reverse display of variables with DW_END_big, DW_END_little
(DW_AT_endianity) dwarf attributes if different than the native
byte order.
* ada-lang.c (ada_value_binop):
Use type_byte_order instead of gdbarch_byte_order.
* ada-valprint.c (printstr):
(ada_val_print_string):
* ada-lang.c (value_pointer):
(ada_value_binop):
Use type_byte_order instead of gdbarch_byte_order.
* c-lang.c (c_get_string):
Use type_byte_order instead of gdbarch_byte_order.
* c-valprint.c (c_val_print_array):
Use type_byte_order instead of gdbarch_byte_order.
* cp-valprint.c (cp_print_class_member):
Use type_byte_order instead of gdbarch_byte_order.
* dwarf2loc.c (rw_pieced_value):
Use type_byte_order instead of gdbarch_byte_order.
* dwarf2read.c (read_base_type): Handle DW_END_big,
DW_END_little
* f-lang.c (f_get_encoding):
Use type_byte_order instead of gdbarch_byte_order.
* findvar.c (default_read_var_value):
Use type_byte_order instead of gdbarch_byte_order.
* gdbtypes.c (check_types_equal):
Require matching TYPE_ENDIANITY_NOT_DEFAULT if set.
(recursive_dump_type): Print TYPE_ENDIANITY_BIG,
and TYPE_ENDIANITY_LITTLE if set.
(type_byte_order): new function.
* gdbtypes.h (TYPE_ENDIANITY_NOT_DEFAULT): New macro.
(struct main_type) <flag_endianity_not_default>:
New field.
(type_byte_order): New function.
* infcmd.c (default_print_one_register_info):
Use type_byte_order instead of gdbarch_byte_order.
* p-lang.c (pascal_printstr):
Use type_byte_order instead of gdbarch_byte_order.
* p-valprint.c (pascal_val_print):
Use type_byte_order instead of gdbarch_byte_order.
* printcmd.c (print_scalar_formatted):
Use type_byte_order instead of gdbarch_byte_order.
* solib-darwin.c (darwin_current_sos):
Use type_byte_order instead of gdbarch_byte_order.
* solib-svr4.c (solib_svr4_r_ldsomap):
Use type_byte_order instead of gdbarch_byte_order.
* stap-probe.c (stap_modify_semaphore):
Use type_byte_order instead of gdbarch_byte_order.
* target-float.c (target_float_same_format_p):
Use type_byte_order instead of gdbarch_byte_order.
* valarith.c (scalar_binop):
(value_bit_index):
Use type_byte_order instead of gdbarch_byte_order.
* valops.c (value_cast):
Use type_byte_order instead of gdbarch_byte_order.
* valprint.c (generic_emit_char):
(generic_printstr):
(val_print_string):
Use type_byte_order instead of gdbarch_byte_order.
* value.c (unpack_long):
(unpack_bits_as_long):
(unpack_value_bitfield):
(modify_field):
(pack_long):
(pack_unsigned_long):
Use type_byte_order instead of gdbarch_byte_order.
* findvar.c (unsigned_pointer_to_address):
(signed_pointer_to_address):
(unsigned_address_to_pointer):
(address_to_signed_pointer):
(default_read_var_value):
(default_value_from_register):
Use type_byte_order instead of gdbarch_byte_order.
* gnu-v3-abi.c (gnuv3_make_method_ptr):
Use type_byte_order instead of gdbarch_byte_order.
* riscv-tdep.c (riscv_print_one_register_info):
Use type_byte_order instead of gdbarch_byte_order.
gdb/testsuite/ChangeLog
2019-11-21 Peeter Joot <peeter.joot@lzlabs.com>
* gdb.base/endianity.c: New test.
* gdb.base/endianity.exp: New file.
Change-Id: I4bd98c1b4508c2d7c5a5dbb15d7b7b1cb4e667e2
All implementations of either function use it for the same purpose (except
Darwin, which is a no-op): to prefer a symbol in the current objfile over
symbols with the same name in other objfiles. There does not seem to be a
reason to have both mechanisms for that purpose.
gdb/ChangeLog:
2019-09-20 Christian Biesinger <cbiesinger@google.com>
* solib-darwin.c (darwin_lookup_lib_symbol): Remove.
(_initialize_darwin_solib): Don't set
darwin_so_ops.lookup_lib_global_symbol.
* solib-svr4.c (set_solib_svr4_fetch_link_map_offsets): Call
set_gdbarch_iterate_over_objfiles_in_search_order.
(elf_lookup_lib_symbol): Rename to...
(svr4_iterate_over_objfiles_in_search_order): this, and update
to iterate semantics.
(_initialize_svr4_solib): Don't set lookup_lib_global_symbol.
* solib.c (solib_global_lookup): Remove.
* solist.h (struct target_so_ops): Remove lookup_lib_global_symbol.
(solib_global_lookup): Remove.
* symtab.c (lookup_global_or_static_symbol): Remove call to
solib_global_lookup.
Simon Marchi