leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

x86/regs: Syscall_get_nr() returns -1 for a non-system call

Browse Source 
syscall_get_nr() is defined to return -1 for a non-system call or a
ptrace/seccomp restart; not just any arbitrary number. See comment in
<asm-generic/syscall.h> for the official definition of this function.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210510185316.3307264-7-hpa@zytor.com
This commit is contained in:
H. Peter Anvin 2021-05-10 11:53:15 -07:00 committed by Ingo Molnar
parent 29e9758966
commit 9ddcb87b92
2 changed files with 3 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/kernel/ptrace.c
View File

@ -911,7 +911,7 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 value)
* syscall with TS_COMPAT still set.
*/
regs->orig_ax = value;
if (syscall_get_nr(child, regs) >= 0)
if (syscall_get_nr(child, regs) != -1)
child->thread_info.status |= TS_I386_REGS_POKED;
break;

4
arch/x86/kernel/signal.c
View File

@ -713,7 +713,7 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
save_v86_state((struct kernel_vm86_regs *) regs, VM86_SIGNAL);
/* Are we from a system call? */
if (syscall_get_nr(current, regs) >= 0) {
if (syscall_get_nr(current, regs) != -1) {
/* If so, check system call restarting.. */
switch (syscall_get_error(current, regs)) {
case -ERESTART_RESTARTBLOCK:
@ -793,7 +793,7 @@ void arch_do_signal_or_restart(struct pt_regs *regs, bool has_signal)
}
/* Did we come from a system call? */
if (syscall_get_nr(current, regs) >= 0) {
if (syscall_get_nr(current, regs) != -1) {
/* Restart the system call - no handlers present */
switch (syscall_get_error(current, regs)) {
case -ERESTARTNOHAND: