diff options
Diffstat (limited to 'gitlab/issues/target_missing/host_missing/accel_TCG/1184.toml')
| -rw-r--r-- | gitlab/issues/target_missing/host_missing/accel_TCG/1184.toml | 77 |
1 files changed, 0 insertions, 77 deletions
diff --git a/gitlab/issues/target_missing/host_missing/accel_TCG/1184.toml b/gitlab/issues/target_missing/host_missing/accel_TCG/1184.toml deleted file mode 100644 index f9d6e24eb..000000000 --- a/gitlab/issues/target_missing/host_missing/accel_TCG/1184.toml +++ /dev/null @@ -1,77 +0,0 @@ -id = 1184 -title = "Extra SIGTRAP when breakpoint + watchpoint occur on same instruction" -state = "opened" -created_at = "2022-08-31T18:52:40.414Z" -closed_at = "n/a" -labels = ["GDB", "accel: TCG"] -url = "https://gitlab.com/qemu-project/qemu/-/issues/1184" -host-os = "Ubuntu 18" -host-arch = "x86, but likely platform-agnostic" -qemu-version = "7.1.0" -guest-os = "x86 multiboot stub" -guest-arch = "x86, but likely platform-agnostic" -description = """If a breakpoint and watchpoint occur on the same instruction in TCG, gdb receives a breakpoint notification, a watchpoint notification, and then a SIGTRAP not corresponding to any set breakpoint/watchpoint.""" -reproduce = """Start QEMU via: - -``` -./qemu-system-i386 -display none -accel tcg -kernel kernel.elf -s -S -``` - -Here's the gdb session: - -``` -(gdb) file kernel.elf -Reading symbols from kernel.elf...done. -(gdb) tar rem :1234 -Remote debugging using :1234 -0x0000fff0 in ?? () -(gdb) b _start -Breakpoint 1 at 0x10000c: file kernel.s, line 17. -(gdb) c -Continuing. - -Breakpoint 1, _start () at kernel.s:17 -17 mov eax, 3 -(gdb) b bp -Breakpoint 2 at 0x100011: file kernel.s, line 20. -(gdb) watch *(int*)&value -Hardware watchpoint 3: *(int*)&value -(gdb) c -Continuing. - -Breakpoint 2, bp () at kernel.s:20 -20 mov dword ptr value, eax -(gdb) c -Continuing. - -Hardware watchpoint 3: *(int*)&value - -Old value = 0 -New value = 3 -done () at kernel.s:23 -23 jmp done -(gdb) c -Continuing. - -Program received signal SIGTRAP, Trace/breakpoint trap. -done () at kernel.s:23 -23 jmp done -```""" -additional = """This patch fixes it by disabling the extra debug interrupt if the CPU is already singlestepping, but I'm not certain it's the 'correct' fix? - -```patch ---- a/softmmu/physmem.c -+++ b/softmmu/physmem.c -@@ -894,7 +894,9 @@ void cpu_check_watchpoint(CPUState *cpu, vaddr addr, vaddr len, - * trigger after the current instruction. - */ - qemu_mutex_lock_iothread(); -- cpu_interrupt(cpu, CPU_INTERRUPT_DEBUG); -+ if ((cpu->singlestep_enabled & SSTEP_NOIRQ) == 0) { -+ cpu_interrupt(cpu, CPU_INTERRUPT_DEBUG); -+ } - qemu_mutex_unlock_iothread(); - return; - } - -```""" |