diff options
| author | Yao Qi <yao.qi@linaro.org> | 2017-01-26 14:29:20 +0000 |
|---|---|---|
| committer | Yao Qi <yao.qi@linaro.org> | 2017-01-26 14:29:20 +0000 |
| commit | d8b49cf0c891d09dd58de05ad5cfe396b612cf3b (patch) | |
| tree | 1945cc6c4192def60974bace2ad085169fd43143 /gdb/disasm.c | |
| parent | 658ca58c4d41c7512dcabcbc4a5ea2109045c363 (diff) | |
Don't throw exception in dis_asm_memory_error
Hi,
GDB calls some APIs from opcodes to do disassembly and provide some
call backs. This model makes troubles on C++ exception unwinding,
because GDB is a C++ program, and opcodes is still compiled as C.
As we can see, frame #10 and #12 are C++, while #frame 11 is C,
#10 0x0000000000544228 in memory_error (err=TARGET_XFER_E_IO, memaddr=<optimized out>) at ../../binutils-gdb/gdb/corefile.c:237
#11 0x00000000006b0a54 in print_insn_aarch64 (pc=0, info=0xffffffffeeb0) at ../../binutils-gdb/opcodes/aarch64-dis.c:3185
#12 0x0000000000553590 in gdb_pretty_print_insn (gdbarch=gdbarch@entry=0xbbceb0, uiout=uiout@entry=0xbc73d0, di=di@entry=0xffffffffeeb0,
insn=0xffffffffed40, insn@entry=0xffffffffed90, flags=flags@entry=0,
C++ exception unwinder can't go across frame #11 unless it has
unwind table. However, C program on many architectures doesn't
have it in default. As a result, GDB aborts, which is described
in PR 20939.
This is not the first time we see this kind of problem. We've
had a commit 89525768cd086a0798a504c81fdf7ebcd4c904e1
"Propagate GDB/C++ exceptions across readline using sj/lj-based TRY/CATCH".
We can fix the disassembly bug in a similar way, this is the option one.
Since opcodes is built with gdb, we fix this problem in a different
way as we did for the same issue with readline. Instead of throwing
exception in dis_asm_memory_error, we record the failed memory
address, and throw exception when GDB returns from opcodes disassemblers.
gdb:
2017-01-26 Yao Qi <yao.qi@linaro.org>
Pedro Alves <palves@redhat.com>
PR gdb/20939
* disasm.c (gdb_disassembler::dis_asm_memory_error): Don't
call memory_error, save memaddr instead.
(gdb_disassembler::print_insn): If gdbarch_print_insn returns
negative, cal memory_error.
* disasm.h (gdb_disassembler) <m_err_memaddr>: New field.
gdb/testsuite:
2017-01-26 Yao Qi <yao.qi@linaro.org>
* gdb.base/all-architectures.exp.in (do_arch_tests): Test
disassemble on address 0.
Diffstat (limited to 'gdb/disasm.c')
| -rw-r--r-- | gdb/disasm.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/gdb/disasm.c b/gdb/disasm.c index b58da0f86f..897f2f1412 100644 --- a/gdb/disasm.c +++ b/gdb/disasm.c @@ -135,7 +135,10 @@ void gdb_disassembler::dis_asm_memory_error (int err, bfd_vma memaddr, struct disassemble_info *info) { - memory_error (TARGET_XFER_E_IO, memaddr); + gdb_disassembler *self + = static_cast<gdb_disassembler *>(info->application_data); + + self->m_err_memaddr = memaddr; } /* Wrapper of print_address. */ @@ -765,7 +768,8 @@ fprintf_disasm (void *stream, const char *format, ...) gdb_disassembler::gdb_disassembler (struct gdbarch *gdbarch, struct ui_file *file, di_read_memory_ftype read_memory_func) - : m_gdbarch (gdbarch) + : m_gdbarch (gdbarch), + m_err_memaddr (0) { init_disassemble_info (&m_di, file, fprintf_disasm); m_di.flavour = bfd_target_unknown_flavour; @@ -792,8 +796,13 @@ int gdb_disassembler::print_insn (CORE_ADDR memaddr, int *branch_delay_insns) { + m_err_memaddr = 0; + int length = gdbarch_print_insn (arch (), memaddr, &m_di); + if (length < 0) + memory_error (TARGET_XFER_E_IO, m_err_memaddr); + if (branch_delay_insns != NULL) { if (m_di.insn_info_valid) |