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Diffstat (limited to 'results/classifier/no-thinking-deepseek-r1:32b/output/runtime/1907969')
| -rw-r--r-- | results/classifier/no-thinking-deepseek-r1:32b/output/runtime/1907969 | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/results/classifier/no-thinking-deepseek-r1:32b/output/runtime/1907969 b/results/classifier/no-thinking-deepseek-r1:32b/output/runtime/1907969 new file mode 100644 index 000000000..58e7ba57a --- /dev/null +++ b/results/classifier/no-thinking-deepseek-r1:32b/output/runtime/1907969 @@ -0,0 +1,61 @@ + + + +linux-user/i386: Segfault when mixing threads and signals + +Given the following C program, qemu-i386 will surely and certainly segfault when executing it. +The problem is only noticeable if the program is statically linked to musl's libc and, as written +in the title, it only manifests when targeting i386. + +Removing the pthread calls or the second raise() makes it not segfault. + +The crash is in some part of the TCG-generated code, right when it tries to perform a +%gs-relative access. + +If you want a quick way of cross-compiling this binary: + +* Download a copy of the Zig compiler from https://ziglang.org/download/ +* Compile it with + `zig cc -target i386-linux-musl <C-FILE> -o <OUT>` + +``` +#include <pthread.h> +#include <signal.h> +#include <stdio.h> +#include <string.h> +#include <sys/types.h> +#include <unistd.h> +#include <asm/prctl.h> +#include <sys/syscall.h> + +void sig_func(int sig) +{ + write(1, "hi!\n", strlen("hi!\n")); +} + +void func(void *p) { } + +typedef void *(*F)(void *); + +int main() +{ + pthread_t tid; + + struct sigaction action; + action.sa_flags = 0; + action.sa_handler = sig_func; + + if (sigaction(SIGUSR1, &action, NULL) == -1) { + return 1; + } + + // This works. + raise(SIGUSR1); + + pthread_create(&tid, NULL, (F)func, NULL); + pthread_join(tid, NULL); + + // This makes qemu segfault. + raise(SIGUSR1); +} +``` \ No newline at end of file |