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authorYao Qi <yao.qi@linaro.org>2017-01-26 14:29:20 +0000
committerYao Qi <yao.qi@linaro.org>2017-01-26 14:29:20 +0000
commitd8b49cf0c891d09dd58de05ad5cfe396b612cf3b (patch)
tree1945cc6c4192def60974bace2ad085169fd43143 /gdb/disasm.c
parent658ca58c4d41c7512dcabcbc4a5ea2109045c363 (diff)
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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.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/gdb/disasm.c b/gdb/disasm.c
index b58da0f..897f2f1 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)