From c45c3b4162148077765e94fd17d4481f18d6d44c Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Thu, 8 Aug 2024 23:52:00 +0200 Subject: [gdb] Handle ^C during disassembly In PR gdb/32025, a fatal error was reported when sending a SIGINT to gdb while disassembling. I managed to reproduce this on aarch64-linux in a Leap 15.5 container using this trigger patch: ... gdb_disassembler_memory_reader::dis_asm_read_memory (bfd_vma memaddr, gdb_byte *myaddr, unsigned int len, struct disassemble_info *info) noexcept { + set_quit_flag (); return target_read_code (memaddr, myaddr, len); } ... and a simple gdb command line calling the disassemble command: ... $ gdb -q -batch a.out -ex "disassemble main" ... The following scenario leads to the fatal error: - the disassemble command is executed, - set_quit_flag is called in gdb_disassembler_memory_reader::dis_asm_read_memory, pretending that a user pressed ^C, - target_read_code calls QUIT, which throws a gdb_exception_quit, - the exception propagation mechanism reaches c code in libopcodes and a fatal error triggers because the c code is not compiled with -fexception. Fix this by: - wrapping the body of gdb_disassembler_memory_reader::dis_asm_read_memory in catch_exceptions (which consequently needs moving to a header file), and - reraising the caught exception in default_print_insn using QUIT. Tested on aarch64-linux. Approved-By: Andrew Burgess Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32025 --- gdb/arch-utils.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'gdb/arch-utils.c') diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c index 13984eb..3247c36 100644 --- a/gdb/arch-utils.c +++ b/gdb/arch-utils.c @@ -37,6 +37,7 @@ #include "auxv.h" #include "observable.h" #include "solib-target.h" +#include "event-top.h" #include "gdbsupport/version.h" @@ -1040,7 +1041,11 @@ default_print_insn (bfd_vma memaddr, disassemble_info *info) info->mach, current_program_space->exec_bfd ()); gdb_assert (disassemble_fn != NULL); - return (*disassemble_fn) (memaddr, info); + int res = (*disassemble_fn) (memaddr, info); + + QUIT; + + return res; } /* See arch-utils.h. */ -- cgit v1.1