arch: tile: kernel: signal.c: Use explicitly type case "unsigned long *" for register copy
PATCH 1/1 arch: tile: kernel: signal.c: Use explicitly type case "unsigned long *" for register copy
setup_sigcontext() wants to copy all kernel related registers to user space. So let it copy explicitly instead of copying by exceeding member array border. So let code more clearer and avoid warning.
And for register, better use "unsigned long" instead of "long", too.
The related warning (with allmodconfig under tile):
CC arch/tile/kernel/signal.o
In file included from include/linux/poll.h:11:0,
from include/linux/ring_buffer.h:7,
from include/linux/ftrace_event.h:5,
from include/trace/syscall.h:6,
from include/linux/syscalls.h:81,
from arch/tile/kernel/signal.c:30:
arch/tile/kernel/signal.c: In function 'setup_sigcontext':
arch/tile/kernel/signal.c:116:31: warning: iteration 53u invokes undefined behavior [-Waggressive-loop-optimizations]
err |= __put_user(regs->regs[i], &sc->gregs[i]);
^
./arch/tile/include/asm/uaccess.h:236:26: note: in definition of macro '__put_user_asm'
: "r" (ptr), "r" (x), "i" (-EFAULT))
^
./arch/tile/include/asm/uaccess.h:297:10: note: in expansion of macro '__put_user_8'
case 8: __put_user_8(x, ptr, __ret); break; \
^
arch/tile/kernel/signal.c:116:10: note: in expansion of macro '__put_user'
err |= __put_user(regs->regs[i], &sc->gregs[i]);
^
arch/tile/kernel/signal.c:115:2: note: containing loop
for (i = 0; i < sizeof(struct pt_regs)/sizeof(long); ++i)
^--- arch/tile/kernel/signal.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
arch/tile/kernel/signal.c +3 -2
@@ -112,8 +112,9 @@ int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs) {int i, err =0 ; -for (i =0 ; i <sizeof (struct pt_regs )/sizeof (long ); ++i) - err |=__put_user (regs->regs[i], &sc->gregs[i]); +for (i =0 ; i <sizeof (regs)/sizeof (unsigned long ); ++i) + err |=__put_user (((unsigned long *)regs)[i], + &((unsigned long *)sc)[i]);return err; }
Signature · 1 line
1.9.3
Quoted 3 lines · Chen Gang
setup_sigcontext()wants to copy all kernel related registers to user space. So let it copy explicitly instead of copying by exceeding member array border. So let code more clearer and avoid warning.
Er... Perhaps it would be better to avoid that shite completely and just use __copy_to_user() instead of bothering with loops?
Quoted 8 lines · Al Viro
Quoted 3 lines · Chen Gang
setup_sigcontext()wants to copy all kernel related registers to user space. So let it copy explicitly instead of copying by exceeding member array border. So let code more clearer and avoid warning.Er... Perhaps it would be better to avoid that shite completely and just use
__copy_to_user()instead of bothering with loops?
OK, thanks, I shall send patch v2 for it.
Also use __copy_from_user() instead of the code in restore_sigcontext().
Thanks
Signature · 3 lines
Chen Gang Open, share, and attitude like air, water, and life which God blessed