https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105032
Bug ID: 105032
Summary: Compiling inline ASM x86 causing GCC stuck in an
endless loop with 100% CPU usage
Product: gcc
Version: 11.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: ammarfaizi2 at gmail dot com
Target Milestone: ---
Full story:
https://lore.kernel.org/lkml/9cfcb296-9dfe-aef1-4209-20a3a95c5...@gnuweeb.org/
Compiling inline ASM x86 causing GCC stuck in an endless loop with 100% CPU
usage.
-----------------------------------------
ammarfaizi2@integral2:/tmp$ gcc --version
gcc (Ubuntu 11.2.0-7ubuntu2) 11.2.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
ammarfaizi2@integral2:/tmp$ gcc -m32 -o test test.c # stuck here...
^C
ammarfaizi2@integral2:/tmp$
-----------------------------------------
Reproducer:
-----------------------------------------
#include <sys/mman.h>
#include <stddef.h>
#include <syscall.h>
#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \
({ \
long _ret; \
register long _num asm("eax") = (num); \
register long _arg1 asm("ebx") = (long)(arg1); \
register long _arg2 asm("ecx") = (long)(arg2); \
register long _arg3 asm("edx") = (long)(arg3); \
register long _arg4 asm("esi") = (long)(arg4); \
register long _arg5 asm("edi") = (long)(arg5); \
long _arg6 = (long)(arg6); /* Always be in memory */ \
\
asm volatile ( \
"pushl %[_arg6]\n\t" \
"pushl %%ebp\n\t" \
"movl 4(%%esp), %%ebp\n\t" \
"int $0x80\n\t" \
"popl %%ebp\n\t" \
"addl $4,%%esp\n\t" \
: "=a"(_ret) \
: "r"(_num), "r"(_arg1), "r"(_arg2), "r"(_arg3), \
"r"(_arg4),"r"(_arg5), [_arg6]"m"(_arg6) \
: "memory", "cc" \
); \
_ret; \
})
static void *__sys_mmap(void *addr, size_t length, int prot, int flags, int fd,
off_t offset)
{
offset >>= 12;
return (void *)my_syscall6(__NR_mmap2, addr, length, prot, flags, fd,
offset);
}
int main(void)
{
__sys_mmap(NULL, 0x1000, PROT_READ|PROT_WRITE,
MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
return 0;
}
