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Diffstat (limited to 'results/classifier/user-mode-bugs/837')
| -rw-r--r-- | results/classifier/user-mode-bugs/837 | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/results/classifier/user-mode-bugs/837 b/results/classifier/user-mode-bugs/837 new file mode 100644 index 000000000..73249b93c --- /dev/null +++ b/results/classifier/user-mode-bugs/837 @@ -0,0 +1,32 @@ + + +x86 user: icebp/int1 raises wrong signal +Description of problem: +This is a relatively minor inaccuracy. When `icebp` (`F1`) is executed, it raises `SIGILL` in QEMU, where the behavior on baremetal Linux (on an old Intel Core i5-430m) is to raise `SIGTRAP`. + +Specifically, on the architectural level, `icebp` raises `#DB` without affecting `dr6`. + +This also happens on an AArch64 host. +``` +$ ./icebp +Trace/breakpoint trap +$ qemu-x86_64 ./icebp +qemu: uncaught target signal 4 (Illegal instruction) - core dumped +Illegal instruction +``` +Steps to reproduce: +1. Compile this file using `gcc -nostdlib -static icebp.S -o icebp`, optionally with `-m32` to test i386 +``` + .globl _start +_start: + .byte 0xF1 // gas doesn't assemble this instruction opcode but it disassembles it +#ifdef __x86_64__ + mov $60, %eax + syscall +#else + mov $1, %eax + int $0x80 +#endif +``` +2. Run on baremetal. Notice how it raises `SIGTRAP` according to the shell job control message +3. Run on qemu-user. Notice how it raises `SIGILL`. |