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| author | Christian Krinitsin <mail@krinitsin.com> | 2025-07-08 13:28:15 +0200 |
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| committer | Christian Krinitsin <mail@krinitsin.com> | 2025-07-08 13:28:28 +0200 |
| commit | 5aa276efcbd67f4300ca1a7f809c6e00aadb03da (patch) | |
| tree | 9b8f0e074014cda8d42f5a97a95bc25082d8b764 /results/classifier/zero-shot-user-mode/instruction/1648 | |
| parent | 1a3c4faf4e0a25ed0b86e8739d5319a634cb9112 (diff) | |
| download | emulator-bug-study-5aa276efcbd67f4300ca1a7f809c6e00aadb03da.tar.gz emulator-bug-study-5aa276efcbd67f4300ca1a7f809c6e00aadb03da.zip | |
restructure results
Diffstat (limited to 'results/classifier/zero-shot-user-mode/instruction/1648')
| -rw-r--r-- | results/classifier/zero-shot-user-mode/instruction/1648 | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/results/classifier/zero-shot-user-mode/instruction/1648 b/results/classifier/zero-shot-user-mode/instruction/1648 new file mode 100644 index 00000000..77e8a220 --- /dev/null +++ b/results/classifier/zero-shot-user-mode/instruction/1648 @@ -0,0 +1,64 @@ +instruction: 0.607 +runtime: 0.209 +syscall: 0.185 + + + +linux-user: incorrect alignment of sigframe::pretcode & rt_sigframe::pretcode cause crash +Description of problem: +Corrent Print Result: + +sp: cdd3b4e8 + +SUCCEEDED! + +qemu-x86_64 Print Result: + +sp: 2804170 + +qemu: uncaught target signal 11 (Segmentation fault) - core dumped + +Segmentation fault + +Reason of Bug: + +sigframe::pretcode & rt_sigframe::pretcode must align of 16n-sizeof(void*) instead of 16n, Because rsp align of 16n before instruction "call" in caller, After "call", push address of "call" in caller. sp of begin in callee is 16n-sizeof(void*) + +For example on x86_64: + +reference to "qemu/linux-user/i386/signal.c" + +``` +# define TARGET_FPSTATE_FXSAVE_OFFSET 0 + +struct rt_sigframe { + abi_ulong pretcode; + struct target_ucontext uc; + struct target_siginfo info; + struct target_fpstate fpstate QEMU_ALIGNED(16); +}; +#define TARGET_RT_SIGFRAME_FXSAVE_OFFSET ( \ + offsetof(struct rt_sigframe, fpstate) + TARGET_FPSTATE_FXSAVE_OFFSET) +``` + +offsetof(struct rt_sigframe, fpstate) align of 16 + +TARGET_FPSTATE_FXSAVE_OFFSET is 0 + +TARGET_RT_SIGFRAME_FXSAVE_OFFSET is 16n, also alignment of fxsave is 64 + +so address of rt_sigframe::pretcode is 16n instead of 16n - sizeof(void*), It is incorect! + +Fix the bug: + +``` +struct rt_sigframe { + abi_ulong pretcode; + struct target_ucontext uc; + struct target_siginfo info; + abi_ulong unused QEMU_ALIGNED(16); + struct target_fpstate fpstate; +}; +``` + +offsetof(struct rt_sigframe, fpstate) is 16n+8, so address of rt_sigframe::pretcode is 16n-8 on x86_64. |