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| author | Christian Krinitsin <mail@krinitsin.com> | 2025-06-16 16:59:00 +0000 |
|---|---|---|
| committer | Christian Krinitsin <mail@krinitsin.com> | 2025-06-16 16:59:33 +0000 |
| commit | 9aba81d8eb048db908c94a3c40c25a5fde0caee6 (patch) | |
| tree | b765e7fb5e9a3c2143c68b0414e0055adb70e785 /results/classifier/118/kernel/1184 | |
| parent | b89a938452613061c0f1f23e710281cf5c83cb29 (diff) | |
| download | emulator-bug-study-9aba81d8eb048db908c94a3c40c25a5fde0caee6.tar.gz emulator-bug-study-9aba81d8eb048db908c94a3c40c25a5fde0caee6.zip | |
add 18th iteration of classifier
Diffstat (limited to 'results/classifier/118/kernel/1184')
| -rw-r--r-- | results/classifier/118/kernel/1184 | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/results/classifier/118/kernel/1184 b/results/classifier/118/kernel/1184 new file mode 100644 index 00000000..5f546902 --- /dev/null +++ b/results/classifier/118/kernel/1184 @@ -0,0 +1,99 @@ +i386: 0.994 +TCG: 0.991 +kernel: 0.971 +x86: 0.971 +debug: 0.967 +graphic: 0.962 +files: 0.958 +architecture: 0.951 +peripherals: 0.915 +device: 0.887 +performance: 0.886 +PID: 0.862 +user-level: 0.801 +socket: 0.749 +semantic: 0.730 +network: 0.703 +KVM: 0.701 +hypervisor: 0.692 +assembly: 0.676 +ppc: 0.630 +register: 0.612 +mistranslation: 0.611 +vnc: 0.592 +permissions: 0.586 +risc-v: 0.573 +VMM: 0.565 +boot: 0.508 +arm: 0.465 +virtual: 0.355 + +Extra SIGTRAP when breakpoint + watchpoint occur on same instruction +Description of problem: +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. +Steps to 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 information: +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; + } + +``` |