diff options
| author | Nicolas Pitre <nico@cam.org> | 2006-06-22 22:18:45 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2006-06-22 22:18:45 +0100 |
| commit | f606a6ff222dc7dceeb4d0e214ce4f55d9c6b0e6 (patch) | |
| tree | 6a44374b8085d5523743268f67bae7fd70e25a43 /arch/arm/kernel | |
| parent | 92b7eb8ffc0741f1fd5fbd5458a466d608310442 (diff) | |
[ARM] 3626/1: ARM EABI: fix syscall restarting
Patch from Nicolas Pitre
The RESTARTBLOCK case currently store some code on the stack to invoke
sys_restart_syscall. However this is ABI dependent and there is a
mismatch with the way __NR_restart_syscall gets defined when the kernel
is compiled for EABI.
There is also a long standing bug in the thumb case since with OABI the
__NR_restart_syscall value includes __NR_SYSCALL_BASE which should not
be the case for Thumb syscalls.
Credits to Yauheni Kaliuta <yauheni.kaliuta@gmail.com> for finding the
EABI bug.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel')
| -rw-r--r-- | arch/arm/kernel/signal.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index a0cd0a90a10..e9fe7803336 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -665,17 +665,33 @@ static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall) if (syscall) { if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) { if (thumb_mode(regs)) { - regs->ARM_r7 = __NR_restart_syscall; + regs->ARM_r7 = __NR_restart_syscall - __NR_SYSCALL_BASE; regs->ARM_pc -= 2; } else { +#if defined(CONFIG_AEABI) && !defined(CONFIG_OABI_COMPAT) + regs->ARM_r7 = __NR_restart_syscall; + regs->ARM_pc -= 4; +#else u32 __user *usp; + u32 swival = __NR_restart_syscall; regs->ARM_sp -= 12; usp = (u32 __user *)regs->ARM_sp; + /* + * Either we supports OABI only, or we have + * EABI with the OABI compat layer enabled. + * In the later case we don't know if user + * space is EABI or not, and if not we must + * not clobber r7. Always using the OABI + * syscall solves that issue and works for + * all those cases. + */ + swival = swival - __NR_SYSCAll_BASE + __NR_OABI_SYSCALL_BASE; + put_user(regs->ARM_pc, &usp[0]); /* swi __NR_restart_syscall */ - put_user(0xef000000 | __NR_restart_syscall, &usp[1]); + put_user(0xef000000 | swival, &usp[1]); /* ldr pc, [sp], #12 */ put_user(0xe49df00c, &usp[2]); @@ -683,6 +699,7 @@ static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall) (unsigned long)(usp + 3)); regs->ARM_pc = regs->ARM_sp + 4; +#endif } } if (regs->ARM_r0 == -ERESTARTNOHAND || |