binutils-gdb/gdb/testsuite/gdb.base/longjmp.exp

# Copyright 2008-2023 Free Software Foundation, Inc.

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

#
# Test support for stepping over longjmp.
#


standard_testfile .c

if  { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug nowarnings}] != "" } {
     untested "failed to compile"
     return -1
}

proc do_test { with_probes } {
    clean_restart ${::binfile}

    if { !$with_probes } {
	gdb_test "maint ignore-probes libc ^longjmp$"
    }

    if {![runto_main]} {
	return 0
    }

    # With a libc with probes, all tests should pass.
    #
    # Without probes, we can still set a break on longjmp, but getting the longjmp
    # target may not work, in the following cases:
    # - gdbarch_get_longjmp_target_p (gdbarch) == 0: not implemented.
    # - gdbarch_get_longjmp_target (gdbarch) == 0: for instance on amd64 if
    #   tdep->jb_pc_offset == -1.
    # - gdbarch_get_longjmp_target (gdbarch) != 0: if we have a glibc with
    #   pointer mangling ( https://sourceware.org/glibc/wiki/PointerEncryption )
    #   then we retrieve a mangled longjmp target that needs to be demangled.
    #   For instance on amd64 with target board unix/-m32.
    #
    # Pointer demangling is currently not implemented for any target.
    # For the amd64 case, this would require copying for instance this:
    #   48 c1 ca 11             ror    $0x11,%rdx
    #   64 48 33 14 25 30 00    xor    %fs:0x30,%rdx
    # into a scratch space, save the register set, set %rdx to the mangled
    # longjmp target, displaced-step through the two insn and read the
    # demangled longjmp target from %rdx, and restore the register set.
    #
    # The failure mode in the first two cases is that the next degrades into a
    # continue.  The failure mode in the latter case is a failure to set a
    # breakpoint (matched by re_cannot_insert_bp) and a stop in longjmp.
    #
    # We detect the different failure modes and kfail these.

    set have_longjmp_probe 0
    gdb_test_multiple "info probes stap libc ^longjmp$" "" {
	-re -wrap "No probes matched\\." {
	    pass $gdb_test_name
	}
	-re -wrap "\r\nstap\[ \t\]+libc\[ \t\]+longjmp\[ \t\]+.*" {
	    pass $gdb_test_name
	    set have_longjmp_probe 1
	}
    }

    if { $with_probes } {
	if { !$have_longjmp_probe } {
	    unsupported "longjmp probe required"
	    return
	}
    } else {
	gdb_assert { !$have_longjmp_probe }
    }

    # When using these line numbers in break linespecs, prefix each of these
    # with "$subdir/$srcfile:" to avoid referring to a glibc file when stopped
    # in __libc_siglongjmp or similar.
    set bp_miss_step_1 [gdb_get_line_number "miss_step_1"]
    set bp_miss_step_2 [gdb_get_line_number "miss_step_2"]

    set bp_start_test_1 [gdb_get_line_number "patt1"]
    set bp_start_test_2 [gdb_get_line_number "patt2"]
    set bp_start_test_3 [gdb_get_line_number "patt3"]

    set re_cannot_insert_bp \
	[multi_line \
	     "Warning:" \
	     "Cannot insert breakpoint $::decimal\\." \
	     "Cannot access memory at address $::hex"]

    #
    # Pattern 1 - simple longjmp.
    #

    with_test_prefix "pattern 1" {

	with_test_prefix setup {
	    delete_breakpoints

	    gdb_test "break $::subdir/$::srcfile:$bp_start_test_1" \
		"Breakpoint.*at.* file .*$::srcfile, line.*$bp_start_test_1.*" \
		"breakpoint at pattern start"
	    gdb_test "continue" "patt1.*" "continue to breakpoint at pattern start"

	    # set safe-net break
	    gdb_test "break $::subdir/$::srcfile:$bp_miss_step_1" \
		"Breakpoint.*at.* file .*$::srcfile, line.*$bp_miss_step_1.*" \
		"breakpoint at safety net"
	}

	gdb_test "next" "longjmps\\+\\+;.*" "next over setjmp"
	gdb_test "next" "longjmp \\(env, 1\\);.*" "next to longjmp"

	set msg "next over longjmp"
	gdb_test_multiple "next" $msg {
	    -re ".*patt1.*$::gdb_prompt $" {
		pass $msg
		gdb_test "next" "resumes\\+\\+.*" "next into else block"
		gdb_test "next" "miss_step_1.*" "next into safety net"
	    }
	    -re "miss_step_1.*$::gdb_prompt $" {
		if { $have_longjmp_probe } {
		    fail $gdb_test_name
		} else {
		    kfail $gdb_test_name "gdb/26967"
		}
	    }
	    -re -wrap "\r\n$re_cannot_insert_bp\r\n.*" {
		if { $have_longjmp_probe } {
		    fail $gdb_test_name
		} else {
		    kfail $gdb_test_name "gdb/26967"
		}
	    }
	}
    }

    #
    # Pattern 2 - longjmp from an inner function.
    #

    with_test_prefix "pattern 2" {

	with_test_prefix setup {
	    delete_breakpoints

	    gdb_test "break $::subdir/$::srcfile:$bp_start_test_2" \
		"Breakpoint.*at.* file .*$::srcfile, line.*$bp_start_test_2.*" \
		"breakpoint at pattern start"
	    gdb_test "continue" "patt2.*" "continue to breakpoint at pattern start"

	    # set safe-net break
	    gdb_test "break $::subdir/$::srcfile:$bp_miss_step_2" \
		"Breakpoint.*at.* file .*$::srcfile, line.*$bp_miss_step_2.*" \
		"breakpoint at safety net"
	}

	gdb_test "next" "call_longjmp.*" "next over setjmp"

	set msg "next over call_longjmp"
	gdb_test_multiple "next" $msg {
	    -re ".*patt2.*$::gdb_prompt $" {
		pass $msg

		gdb_test "next" "resumes\\+\\+.*" "next into else block"
		gdb_test "next" "miss_step_2.*" "next into safety net"
	    }
	    -re "miss_step_2.*$::gdb_prompt $" {
		if { $have_longjmp_probe } {
		    fail $gdb_test_name
		} else {
		    kfail $gdb_test_name "gdb/26967"
		}
	    }
	    -re -wrap "\r\n$re_cannot_insert_bp\r\n.*" {
		if { $have_longjmp_probe } {
		    fail $gdb_test_name
		} else {
		    kfail $gdb_test_name "gdb/26967"
		}
	    }
	}
    }

    #
    # Pattern 3 - setjmp/longjmp inside stepped-over function.
    #

    with_test_prefix "pattern 3" {

	with_test_prefix setup {
	    delete_breakpoints

	    gdb_test "break $::subdir/$::srcfile:$bp_start_test_3" \
		"Breakpoint.*at.* file .*$::srcfile, line.*$bp_start_test_3.*" \
		"breakpoint at pattern start"
	    gdb_test "continue" "patt3.*" "continue to breakpoint at pattern start"
	}

	gdb_test_multiple "next" "next over pattern" {
	    -re -wrap "longjmp caught.*" {
		pass $gdb_test_name
	    }
	    -re -wrap "\r\n$re_cannot_insert_bp\r\n.*" {
		if { $have_longjmp_probe } {
		    fail $gdb_test_name
		} else {
		    kfail $gdb_test_name "gdb/26967"
		}
	    }
	}
    }
}

foreach_with_prefix with_probes { 0 1 } {
    do_test $with_probes
}