In certain cases we were calculating the jump displacement incorrectly
when deciding whether to relax a branch. This meant for some branches,
such as a very long backwards conditional branch, relaxation was not
done when it should have been. The result was to error later, because
the actual jump displacement was too large to fit in the original
instruction.
This patch fixes up the displacement calculation so that those branches
are correctly relaxed and no longer result in an error. In addition, it
changes md_convert_frag to install fixups for the JAL instructions in
the resulting relaxations rather than encoding the displacement value
directly.
gas/
* config/tc-bpf.c (relaxed_branch_length): Correct displacement
calculation when relaxing.
(md_convert_frag): Likewise. Install fixups for JAL
instructions resulting from relaxation.
* testsuite/gas/bpf/jump-relax-ja-be.d: Correct and expand test.
* testsuite/gas/bpf/jump-relax-ja.d: Likewise.
* testsuite/gas/bpf/jump-relax-ja.s: Likewise.
* testsuite/gas/bpf/jump-relax-jump-be.d: Likewise.
* testsuite/gas/bpf/jump-relax-jump.d: Likewise.
* testsuite/gas/bpf/jump-relax-jump.s: Likewise.
As a result of a switch instead of an if, as would issue non-specific
error messages when it encountered an operand it could not parse in bpf.
This patch fixes that regression and adds a test to prevent it from
reoccurring.
Tested for bpf-unknown-none on x86_64-redhat-linux.
gas/ChangeLog:
* config/tc-bpf.c (parse_expression): Change switch to if so that error
* condition is handled.
* testsuite/gas/bpf/bpf.exp: Invoke new test.
* testsuite/gas/bpf/indcall-badoperand.d: New test.
* testsuite/gas/bpf/indcall-badoperand.l: New test.
* testsuite/gas/bpf/indcall-badoperand.s: New test.
The PARSE_ERROR macro in md_assemble performs pointer subtraction. If
parse_expression returns NULL then the later will be part of the
subtraction and therefore UB will be incurred.
This patch changes md_assemble to:
1. Accommodate all invocations to parse_expression to the fact it will
return NULL when a parse error occurs.
2. Avoid UB in PARSE_ERROR.
Tested in bpf-unknown-none target / x86_64-linux-gnu host.
gas/ChangeLog:
* config/tc-bpf.c (md_assemble): Fix to take into account that
parse_expression can return NULL.
(PARSE_ERROR): Avoid passing invalid length to parse_error.
Adds two new external authors to etc/update-copyright.py to cover
bfd/ax_tls.m4, and adds gprofng to dirs handled automatically, then
updates copyright messages as follows:
1) Update cgen/utils.scm emitted copyrights.
2) Run "etc/update-copyright.py --this-year" with an extra external
author I haven't committed, 'Kalray SA.', to cover gas testsuite
files (which should have their copyright message removed).
3) Build with --enable-maintainer-mode --enable-cgen-maint=yes.
4) Check out */po/*.pot which we don't update frequently.
The BPF assembler in clang uses semi-colon (;) to separate statements,
not to be begin line comments. This patch adapts the GNU assembler
accordingly.
Testsuite and documentation updated accordingly.
2023-11-28 Jose E. Marchesi <jose.marchesi@oracle.com>
* config/tc-bpf.c: Semicolon does not start a comment, but
separates multiple commands on a single line.
* testsuite/gas/bpf/alu-pseudoc.s: Adapt test accordingly.
* testsuite/gas/bpf/spacing-pseudoc.s: Likewise.
* testsuite/gas/bpf/offset16-overflow.s: Likewise.
* testsuite/gas/bpf/jump-relax-jump.s: Likewise.
* testsuite/gas/bpf/jump-relax-ja.s: Likewise.
* testsuite/gas/bpf/imm32-overflow.s: Likewise.
* testsuite/gas/bpf/disp32-overflow.s: Likewise.
* testsuite/gas/bpf/disp16-overflow-relax.s: Likewise.
* testsuite/gas/bpf/disp16-overflow.s: Likewise.
* doc/c-bpf.texi (BPF Special Characters): Update.
This changes parse_bpf_register to detect possible symbols that start with valid
register name, however due some following characters are not.
Also changed the regs-for-symbols-pseudo.s, adding some entries that
should not error if parser is properly detecting the symbol.
2023-11-18 Jose E. Marchesi <jemarch@gnu.org>
* config/tc-bpf.c (parse_bpf_register): Move before
bpf_parse_name.
(bpf_parse_name): Do not allow using symbols that are also
register names as operands in pseudo-c syntax.
* testsuite/gas/bpf/regs-for-symbols-pseudoc.d: New file.
* testsuite/gas/bpf/regs-for-symbols-pseudoc.s: Likewise.
* testsuite/gas/bpf/regs-for-symbols-pseudoc.l: Likewise.
* doc/c-bpf.texi (BPF Registers): Document that it is not possible
to refer to register names as symbols in instruction operands.
To support the "pseudo-C" asm dialect in BPF, the BPF parser must often
attempt multiple different templates for a single instruction. In some
cases this can cause the parser to incorrectly parse part of the
instruction opcode as an expression, which leads to the creation of a
new undefined symbol.
Once the parser recognizes the error, the expression is discarded and it
tries again with a new instruction template. However, symbols created
during the process are added to the symbol table and are not removed
even if the expression is discarded.
This is a problem for BPF: generally the assembled object will be loaded
directly to the Linux kernel, without being linked. These erroneous
parser-created symbols are rejected by the kernel BPF loader, and the
entire object is refused.
This patch remedies the issue by tentatively creating symbols while
parsing instruction operands, and storing them in a temporary list
rather than immediately inserting them into the symbol table. Later,
after the parser is sure that it has correctly parsed the instruction,
those symbols are committed to the real symbol table.
This approach is modeled directly after Jan Beulich's patch for RISC-V:
commit 7a29ee2903
RISC-V: adjust logic to avoid register name symbols
Many thanks to Jan for recognizing the problem as similar, and pointing
me to that patch.
gas/
* config/tc-bpf.c (parsing_insn_operands): New.
(parse_expression): Set it here.
(deferred_sym_rootP, deferred_sym_lastP): New.
(orphan_sym_rootP, orphan_sym_lastP): New.
(bpf_parse_name): New.
(parse_error): Clear deferred symbol list on error.
(md_assemble): Clear parsing_insn_operands. Commit deferred
symbols to symbol table on successful parse.
* config/tc-bpf.h (md_parse_name): Define to...
(bpf_parse_name): ...this. New prototype.
* testsuite/gas/bpf/asm-extra-sym-1.s: New test source.
* testsuite/gas/bpf/asm-extra-sym-1.d: New test.
* testsuite/gas/bpf/bpf.exp: Run new test.
This commit changes the BPF GAS port in order to handle immediate
overflows the same way than the clang BPF assembler:
- For an immediate field of N bits, any written number (positive or
negative) whose two's complement encoding fit in N its is accepted.
This means that -2 is the same than 0xffffffe. It is up to the
instructions to decide how to interpret the encoded value.
- Immediate fields in jump instructions are no longer relaxed.
Relaxing to jump instructions with wider range is only performed
when expressions are involved.
- The manual is updated to document this, and testsuite adapted
accordingly.
Tested in x86_64-linux-gnu host, bpf-unknown-none target.
gas/ChangeLog:
2023-08-17 Jose E. Marchesi <jose.marchesi@oracle.com>
* config/tc-bpf.c (check_immediate_overflow): New function.
(encode_insn): Use check_immediate_overflow.
(md_assemble): Do not relax instructions with
constant disp16 fields.
* doc/c-bpf.texi (BPF Instructions): Add note about how numerical
literal values are interpreted for instruction immediate operands.
* testsuite/gas/bpf/disp16-overflow.s: Adapt accordingly.
* testsuite/gas/bpf/jump-relax-jump.s: Likewise.
* testsuite/gas/bpf/jump-relax-jump.d: Likewise.
* testsuite/gas/bpf/jump-relax-jump-be.d: Likewise.
* testsuite/gas/bpf/jump-relax-ja.s: Likewise.
* testsuite/gas/bpf/jump-relax-ja.d: Likewise.
* testsuite/gas/bpf/jump-relax-ja-be.d: Likewise.
* testsuite/gas/bpf/disp16-overflow-relax.l: Likewise.
* testsuite/gas/bpf/imm32-overflow.s: Likewise.
* testsuite/gas/bpf/disp32-overflow.s: Likewise.
* testsuite/gas/bpf/disp16-overflow.l: Likewise.
* testsuite/gas/bpf/disp32-overflow.l: Likewise.
* testsuite/gas/bpf/imm32-overflow.l: Likewise.
* testsuite/gas/bpf/offset16-overflow.l: Likewise.
This patch adds support for EF_BPF_CPUVER bits in the ELF
machine-dependent header flags. These bits encode the BPF CPU
version for which the object file has been compiled for.
The BPF assembler is updated so it annotates the object files it
generates with these bits.
The BPF disassembler is updated so it honors EF_BPF_CPUVER to use the
appropriate ISA version if the user didn't specify an explicit ISA
version in the command line. Note that a value of zero in
EF_BPF_CPUVER is interpreted by the disassembler as "use the later
supported version" (the BPF CPU versions start with v1.)
The readelf utility is updated to pretty print EF_BPF_CPUVER when it
prints out the ELF header:
$ readelf -h a.out
ELF Header:
...
Flags: 0x4, CPU Version: 4
Tested in bpf-unknown-none.
include/ChangeLog:
2023-07-30 Jose E. Marchesi <jose.marchesi@oracle.com>
* elf/bpf.h (EF_BPF_CPUVER): Define.
* opcode/bpf.h (BPF_XBPF): Change from 0xf to 0xff so it fits in
EF_BPF_CPUVER.
binutils/ChangeLog:
2023-07-30 Jose E. Marchesi <jose.marchesi@oracle.com>
* readelf.c (get_machine_flags): Recognize and pretty print BPF
machine flags.
opcodes/ChangeLog:
2023-07-30 Jose E. Marchesi <jose.marchesi@oracle.com>
* bpf-dis.c: Initialize asm_bpf_version to -1.
(print_insn_bpf): Set BPF ISA version from the cpu version ELF
header flags if no explicit version set in the command line.
* disassemble.c (disassemble_init_for_target): Remove unused code.
gas/ChangeLog:
2023-07-30 Jose E. Marchesi <jose.marchesi@oracle.com>
* config/tc-bpf.h (elf_tc_final_processing): Define.
* config/tc-bpf.c (bpf_elf_final_processing): New function.
The BPF jump-always instruction (JA), like all other jump instructions
in the ISA, get a signed 16-bit displacement target argument denoted
in number of 64-bit words minus one. This can sometimes be overflown.
The BPF V4 ISA thus introduced support for a jump-always
instruction (JAL) that gets a signed 32-bit displacement instead.
This patch makes the BPF assembler to perform the following
relaxations when the disp16 field gets overflown, unless the option
-mno-relax is specified:
JA disp16 -> JAL disp32
Jxx disp16 -> Jxx +1; JA +1; JAL disp32
Documentation and tests added.
Tested in bpf-unknown-none.
gas/ChangeLog:
2023-07-28 Jose E. Marchesi <jose.marchesi@oracle.com>
PR gas/30690
* config/tc-bpf.c (struct bpf_insn): Add fields is_relaxable and
relaxed_exp.
(enum options): Add OPTION_NO_RELAX.
(md_longopts): Likewise for -mno-relax.
(do_relax): New global.
(md_parse_option): Handle OPTION_NO_RELAX.
(RELAX_BRANCH_ENCODE): Define.
(RELAX_BRANCH_P): Likewise.
(RELAX_BRANCH_LENGTH): Likewise.
(RELAX_BRANCH_CONST): Likewise.
(RELAX_BRANCH_UNCOND): Likewise.
(relaxed_branch_length): New function.
(md_estimate_size_before_relax): Likewise.
(read_insn_word): Likewise.
(encode_int16): Likewise.
(encode_int32): Likewise.
(write_insn_bytes): Likewise.
(md_convert_frag): Likewise.
(encode_insn): Likewise.
(install_insn_fixups): Likewise.
(add_fixed_insn): Likewise.
(add_relaxed_insn): Likewise.
(md_assemble): Move instruction encoding logic to the above
new functions.
* testsuite/gas/bpf/jump-relax-ja.d: New test.
* testsuite/gas/bpf/jump-relax-ja-be.d: Likewise.
* testsuite/gas/bpf/jump-relax-ja.s: And corresponding source.
* testsuite/gas/bpf/jump-relax-jump.d: New test.
* testsuite/gas/bpf/jump-relax-jump-be.d: Likewise.
* testsuite/gas/bpf/jump-relax-jump.s: And corresponding source.
* testsuite/gas/bpf/bpf.exp: Run new tests.
* doc/c-bpf.texi (BPF Options): Document -mno-relax.
This little patch makes the BPF assembler accept '#' as an inline
comment character, which clang -S seems to use.
gas/
* config/tc-bpf.c (comment_chars): Add '#'.
* doc/c-bpf.texi (BPF Special Characters): Add note that '#' may
be used for inline comments.
This patch adds support for the V4 BPF instruction jal/gotol, which is
like ja/goto but it supports a signed 32-bit PC-relative (in number of
64-bit words minus one) target operand instead of the 16-bit signed
operand of the other instruction. This greatly increases the jump
range in BPF programs.
Tested in bpf-unkown-none.
bfd/ChangeLog:
2023-07-24 Jose E. Marchesi <jose.marchesi@oracle.com>
* reloc.c: New reloc BFD_RELOC_BPF_DISPCALL32.
* elf64-bpf.c (bpf_reloc_type_lookup): Handle the new reloc.
* libbfd.h (bfd_reloc_code_real_names): Regenerate.
gas/ChangeLog:
2023-07-24 Jose E. Marchesi <jose.marchesi@oracle.com>
* config/tc-bpf.c (struct bpf_insn): New field `id'.
(md_assemble): Save the ids of successfully parsed instructions
and use the new BFD_RELOC_BPF_DISPCALL32 whenever appropriate.
(md_apply_fix): Adapt to the new BFD reloc.
* testsuite/gas/bpf/jump.s: Test JAL.
* testsuite/gas/bpf/jump.d: Likewise.
* testsuite/gas/bpf/jump-pseudoc.d: Likewise.
* testsuite/gas/bpf/jump-be.d: Likewise.
* testsuite/gas/bpf/jump-be-pseudoc.d: Likewise.
* doc/c-bpf.texi (BPF Instructions): Document new instruction
jal/gotol.
Document new operand type disp32.
include/ChangeLog:
2023-07-24 Jose E. Marchesi <jose.marchesi@oracle.com>
* opcode/bpf.h (enum bpf_insn_id): Add entry BPF_INSN_JAL.
(enum bpf_insn_id): Remove spurious entry BPF_INSN_CALLI.
opcodes/ChangeLog:
2023-07-23 Jose E. Marchesi <jose.marchesi@oracle.com>
* bpf-opc.c (bpf_opcodes): Add entry for jal.
CGEN is cool, but the BPF architecture is simply too bizarre for it.
The weird way of BPF to handle endianness in instruction encoding, the
weird C-like alternative assembly syntax, the weird abuse of
multi-byte (or infra-byte) instruction fields as opcodes, the unusual
presence of opcodes beyond the first 32-bits of some instructions, are
all examples of what makes it a PITA to continue using CGEN for this
port. The bpf.cpu file is becoming so complex and so nested with
p-macros that it is very difficult to read, and quite challenging to
update. Also, every time we are forced to change something in CGEN to
accommodate BPF requirements (which is often) we have to do extensive
testing to make sure we do not break any other target using CGEN.
This is getting un-maintenable.
So I have decided to bite the bullet and revamp/rewrite the port so it
no longer uses CGEN. Overall, this involved:
* To remove the cpu/bpf.{cpu,opc} descriptions.
* To remove the CGEN generated files.
* To replace the CGEN generated opcodes table with a new hand-written
opcodes table for BPF.
* To replace the CGEN generated disassembler wih a new disassembler
that uses the new opcodes.
* To replace the CGEN generated assembler with a new assembler that uses the
new opcodes.
* To replace the CGEN generated simulator with a new simulator that uses the
new opcodes. [This is pushed in GDB in another patch.]
* To adapt the build systems to the new situation.
Additionally, this patch introduces some extensions and improvements:
* A new BPF relocation BPF_RELOC_BPF_DISP16 plus corresponding ELF
relocation R_BPF_GNU_64_16 are added to the BPF BFD port. These
relocations are used for section-relative 16-bit offsets used in
load/store instructions.
* The disassembler now has support for the "pseudo-c" assembly syntax of
BPF. What dialect to use when disassembling is controlled by a command
line option.
* The disassembler now has support for dumping instruction immediates in
either octal, hexadecimal or decimal. The used output base is controlled
by a new command-line option.
* The GAS BPF test suite has been re-structured and expanded in order to
test the disassembler pseudoc syntax support. Minor bugs have been also
fixed there. The assembler generic tests that were disabled for bpf-*-*
targets due to the previous implementation of pseudoc syntax are now
re-enabled. Additional tests have been added to test the new features of
the assembler. .dump files are no longer used.
* The linker BPF test suite has been adapted to the command line options
used by the new disassembler.
The result is very satisfactory. This patchs adds 3448 lines of code
and removes 10542 lines of code.
Tested in:
* Target bpf-unknown-none with 64-bit little-endian host and 32-bit
little-endian host.
* Target x86-64-linux-gnu with --enable-targets=all
Note that I have not tested in a big-endian host yet. I will do so
once this lands upstream so I can use the GCC compiler farm.
I have not included ChangeLog entries in this patch: these would be
massive and not very useful, considering this is pretty much a rewrite
of the port. I beg the indulgence of the global maintainers.
char is unsigned on s390x, so there are a lot of warnings like:
gas/config/tc-bpf.c: In function 'get_token':
gas/config/tc-bpf.c:900:14: error: comparison is always false due to limited range of data type [-Werror=type-limits]
900 | if (ch == EOF || len > MAX_TOKEN_SZ)
| ^~
Change its type to int, like in the other similar code.
There is also:
gas/config/tc-bpf.c:735:30: error: 'bpf_endianness' may be used uninitialized in this function [-Werror=maybe-uninitialized]
735 | dst, be ? size[endianness - BPF_BE16] : size[endianness - BPF_LE16]);
| ~~~~~~~~~~~^~~~~~~~~~
-Wmaybe-uninitialized doesn't seem to understand the FSM; just
initialize bpf_endianness to silence it. Add an assertion to
build_bpf_endianness() in order to catch potential bugs.
This patch adds support to the GNU assembler for an alternative
assembly syntax used in BPF. This syntax is C-like and very
unconventional for an assembly language, but it is generated by
clang/llvm and is also used in inline asm templates in kernel code, so
we ought to support it.
After this patch, the assembler is able to parse instructions in both
supported syntax: the normal assembly-like syntax and the pseudo-C
syntax. Instruction formats can be mixed in the source program: the
assembler recognizes the right syntax to use.
gas/ChangeLog:
2023-04-20 Guillermo E. Martinez <guillermo.e.martinez@oracle.com>
PR gas/29728
* config/tc-bpf.h (TC_EQUAL_IN_INSN): Define.
* config/tc-bpf.c (LEX_IS_SYMBOL_COMPONENT): Define.
(LEX_IS_WHITESPACE): Likewise.
(LEX_IS_NEWLINE): Likewise.
(LEX_IS_ARITHM_OP): Likewise.
(LEX_IS_STAR): Likewise.
(LEX_IS_CLSE_BR): Likewise.
(LEX_IS_OPEN_BR): Likewise.
(LEX_IS_EQUAL): Likewise.
(LEX_IS_EXCLA): Likewise.
(ST_EOI): Likewise.
(MAX_TOKEN_SZ): Likewise.
(init_pseudoc_lex): New function.
(md_begin): Call init_pseudoc_lex.
(valid_expr): New function.
(build_bpf_non_generic_load): Likewise.
(build_bpf_atomic_insn): Likewise.
(build_bpf_jmp_insn): Likewise.
(build_bpf_arithm_insn): Likewise.
(build_bpf_endianness): Likewise.
(build_bpf_load_store_insn): Likewise.
(look_for_reserved_word): Likewise.
(is_register): Likewise.
(is_cast): Likewise.
(get_token): Likewise.
(bpf_pseudoc_to_normal_syntax): Likewise.
(md_assemble): Try pseudo-C syntax if an instruction cannot be
parsed.
The newer update-copyright.py fixes file encoding too, removing cr/lf
on binutils/bfdtest2.c and ld/testsuite/ld-cygwin/exe-export.exp, and
embedded cr in binutils/testsuite/binutils-all/ar.exp string match.
The result of running etc/update-copyright.py --this-year, fixing all
the files whose mode is changed by the script, plus a build with
--enable-maintainer-mode --enable-cgen-maint=yes, then checking
out */po/*.pot which we don't update frequently.
The copy of cgen was with commit d1dd5fcc38ead reverted as that commit
breaks building of bfp opcodes files.
This patch adds support for xBPF, another ISA targetting the BPF
virtual architecture. For now, the primary difference between eBPF
and xBPF is that xBPF supports indirect calls through the
'call %reg' form of the call instruction.
bfd/
* archures.c (bfd_mach_xbpf): Define.
* bfd-in2.h: Regenerate.
* cpu-bpf.c (bfd_xbpf_arch) New.
(bfd_bpf_arch) Update next in list field to point to xbpf arch.
cpu/
* bpf.cpu (arch bpf): Add xbpf mach and isas.
(define-xbpf-isa) New pmacro.
(all-isas) Add xbpfle,xbpfbe.
(endian-isas): New pmacro.
(mach xbpf): New.
(model xbpf-def): Likewise.
(h-gpr): Add xbpf mach.
(f-dstle, f-srcle, dstle, srcle): Add xbpfle isa.
(f-dstbe, f-srcbe, dstbe, srcbe): Add xbpfbe isa.
(define-alu-insn-un): Use new endian-isas pmacro.
(define-alu-insn-bin, define-alu-insn-mov): Likewise.
(define-endian-insn, define-lddw): Likewise.
(dlind, dxli, dxsi, dsti): Likewise.
(define-cond-jump-insn, define-call-insn): Likewise.
(define-atomic-insns): Likewise.
gas/
* config/tc-bpf.c: Add option -mxbpf to select xbpf isa.
* testsuite/gas/bpf/indcall-1.d: New file.
* testsuite/gas/bpf/indcall-1.s: Likewise.
* testsuite/gas/bpf/indcall-bad-1.l: Likewise.
* testsuite/gas/bpf/indcall-bad-1.s: Likewise.
* testsuite/gas/bpf/bpf.exp: Run new tests.
opcodes/
* bpf-desc.c: Regenerate.
* bpf-desc.h: Likewise.
* bpf-opc.c: Likewise.
* bpf-opc.h: Likewise.
* disassemble.c (disassemble_init_for_target): Set bits for xBPF
ISA when appropriate.
The GAS struct frag ends with a field `fr_literal' whose purpose is to
mark the begining of the frag's data:
struct frag {
...
/* Data begins here. */
char fr_literal[1];
};
The code in gas/config/tc-bpf.c recently committed:
where = fixP->fx_frag->fr_literal + fixP->fx_where;
where[1] = target_big_endian ? 0x01 : 0x10;
triggers the stringop-overflow warning in GCC 10+, since the compiler
assumes the size of the modified buffer is 1 byte. This patch
slightly modifies the code to make tc-bpf.c buildable with GCC 10+.
2020-06-05 Jose E. Marchesi <jose.marchesi@oracle.com>
* config/tc-bpf.c (md_apply_fix): Avoid GCC 10 warning
stringop-overflow.
cpu/ChangeLog:
2020-06-02 Jose E. Marchesi <jose.marchesi@oracle.com>
* bpf.cpu (define-bpf-isa): Set base-insn-bitsize to 64.
* bpf.opc (bpf_print_insn): Do not set endian_code here.
gas/ChangeLog:
2020-06-04 Jose E. Marchesi <jose.marchesi@oracle.com>
* config/tc-bpf.c (md_begin): Pass CGEN_CPU_OPEN_INSN_ENDIAN to
bpf_cgen_cpu_open.
(md_assemble): Remove no longer needed hack.
opcodes/ChangeLog:
2020-06-04 Jose E. Marchesi <jose.marchesi@oracle.com>
* disassemble.c (disassemble_init_for_target): Set endian_code for
bpf targets.
* bpf-desc.c: Regenerate.
* bpf-opc.c: Likewise.
* bpf-dis.c: Likewise.
The CGEN support code in opcodes accesses instruction contents using a
couple of functions defined in cgen-opc.c: cgen_get_insn_value and
cgen_put_insn_value. These functions use the "instruction endianness"
in the CPU description to order the read/written bytes.
The process of writing an instruction to the object file is:
a) cgen_put_insn_value ;; Writes out the opcodes.
b) ARCH_cgen_insert_operand
insert_normal
insert_1
cgen_put_insn_value ;; Writes out the bytes of the
;; operand.
Likewise, the process of reading an instruction from the object file
is:
a) cgen_get_insn_value ;; Reads the opcodes.
b) ARCH_cgen_extract_operand
extract_normal
extract_1
cgen_get_insn_value ;; Reads in the bytes of the
;; operand.
As can be seen above, cgen_{get,put}_insn_value are used to both
process the instruction opcodes (the constant fields conforming the
base instruction) and also the values of the instruction operands,
such as immediates.
This is problematic for architectures in which the endianness of
instructions is different to the endianness of data. An example is
BPF, where instructions are always encoded big-endian but the data may
be either big or little.
This patch changes the cgen_{get,put}_insn_value functions in order to
get an extra argument with the endianness to use, and adapts the
existin callers to these functions in order to provide cd->endian or
cd->insn_endian, whatever appropriate. Callers like extract_1 and
insert_1 pass cd->endian (since they are reading/writing operand
values) while callers reading/writing the base instruction pass
cd->insn_endian instead.
A few little adjustments have been needed in some existing CGEN based
ports:
* The BPF assembler uses cgen_put_insn_value. It has been adapted to
pass the new endian argument.
* The mep port has code in mep.opc that uses cgen_{get,put}_insn_value.
It has been adapted to pass the new endianargument. Ditto for a
call in the assembler.
Tested with --enable-targets=all.
Regested in all supported targets.
No regressions.
include/ChangeLog:
2020-06-04 Jose E. Marchesi <jose.marchesi@oracle.com>
* opcode/cgen.h: Get an `endian' argument in both
cgen_get_insn_value and cgen_put_insn_value.
opcodes/ChangeLog:
2020-06-04 Jose E. Marchesi <jose.marchesi@oracle.com>
* cgen-opc.c (cgen_get_insn_value): Get an `endian' argument.
(cgen_put_insn_value): Likewise.
(cgen_lookup_insn): Pass endianness to cgen_{get,put}_insn_value.
* cgen-dis.in (print_insn): Likewise.
* cgen-ibld.in (insert_1): Likewise.
(insert_1): Likewise.
(insert_insn_normal): Likewise.
(extract_1): Likewise.
* bpf-dis.c: Regenerate.
* bpf-ibld.c: Likewise.
* bpf-ibld.c: Likewise.
* cgen-dis.in: Likewise.
* cgen-ibld.in: Likewise.
* cgen-opc.c: Likewise.
* epiphany-dis.c: Likewise.
* epiphany-ibld.c: Likewise.
* fr30-dis.c: Likewise.
* fr30-ibld.c: Likewise.
* frv-dis.c: Likewise.
* frv-ibld.c: Likewise.
* ip2k-dis.c: Likewise.
* ip2k-ibld.c: Likewise.
* iq2000-dis.c: Likewise.
* iq2000-ibld.c: Likewise.
* lm32-dis.c: Likewise.
* lm32-ibld.c: Likewise.
* m32c-dis.c: Likewise.
* m32c-ibld.c: Likewise.
* m32r-dis.c: Likewise.
* m32r-ibld.c: Likewise.
* mep-dis.c: Likewise.
* mep-ibld.c: Likewise.
* mt-dis.c: Likewise.
* mt-ibld.c: Likewise.
* or1k-dis.c: Likewise.
* or1k-ibld.c: Likewise.
* xc16x-dis.c: Likewise.
* xc16x-ibld.c: Likewise.
* xstormy16-dis.c: Likewise.
* xstormy16-ibld.c: Likewise.
gas/ChangeLog:
2020-06-04 Jose E. Marchesi <jose.marchesi@oracle.com>
* cgen.c (gas_cgen_finish_insn): Pass the endianness to
cgen_put_insn_value.
(gas_cgen_md_apply_fix): Likewise.
(gas_cgen_md_apply_fix): Likewise.
* config/tc-bpf.c (md_apply_fix): Pass data endianness to
cgen_put_insn_value.
* config/tc-mep.c (mep_check_ivc2_scheduling): Pass endianness to
cgen_put_insn_value.
cpu/ChangeLog:
2020-06-02 Jose E. Marchesi <jose.marchesi@oracle.com>
* mep.opc (print_slot_insn): Pass the insn endianness to
cgen_get_insn_value.
Tested in a x86_64 host.
gas/ChangeLog:
2019-07-19 Jose E. Marchesi <jose.marchesi@oracle.com>
* config/tc-bpf.c (pe_lcomm_internal): Adapted from tc-i386.c.
(pe_lcomm): Likewise.
(md_pseudo_table): Use pe_lcomm to implement .lcomm.
This little patch adds support to the eBPF port of GAS for a few data
directives. The names for the directives have been chosen to be
coherent with the suffixes used in eBPF instructions: b, h, w and dw
for 8, 16, 32 and 64-bit values respectively.
Documentation and tests included.
Tested in a x86_64 host.
gas/ChangeLog:
2019-07-17 Jose E. Marchesi <jose.marchesi@oracle.com>
* config/tc-bpf.c (md_pseudo_table): .half, .word and .dword.
* testsuite/gas/bpf/data.s: New file.
* testsuite/gas/bpf/data.d: Likewise.
* testsuite/gas/bpf/data-be.d: Likewise.
* testsuite/gas/bpf/bpf.exp: Run data and data-be.
* doc/c-bpf.texi (BPF Directives): New section.
