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| author |   Vineet Gupta <vgupta@synopsys.com> | 2013-01-18 15:12:19 +0530 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2013-02-15 23:15:50 +0530 |
| commit | 55bb9480f9159b229ac3c3454c97b62d1e0a7e80 (patch) | |
| tree | 4de8a97445bb41f250cdadba78169d0463bd244b /arch/arc/include/asm/ptrace.h | |
| parent | ARC: [Review] Preparing to fix incorrect syscall restarts due to signals (diff) | |
| download | linux-dev-55bb9480f9159b229ac3c3454c97b62d1e0a7e80.tar.xz linux-dev-55bb9480f9159b229ac3c3454c97b62d1e0a7e80.zip | |
ARC: [Review] Prevent incorrect syscall restarts
Per Al Viro's "signals for dummies" https://lkml.org/lkml/2012/12/6/366
there are 3 golden rules for (not) restarting syscalls:
" What we need to guarantee is
* restarts do not happen on signals caught in interrupts or exceptions
* restarts do not happen on signals caught in sigreturn()
* restart should happen only once, even if we get through do_signal()
many times."
ARC Port already handled #1, this patch fixes #2 and #3.
We use the additional state in pt_regs->orig_r8 to ckh if restarting
has already been done once.
Thanks to Al Viro for spotting this.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Diffstat (limited to 'arch/arc/include/asm/ptrace.h')
| -rw-r--r-- | arch/arc/include/asm/ptrace.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arc/include/asm/ptrace.h b/arch/arc/include/asm/ptrace.h index 3ec89f467ac3..a98957a95fb3 100644 --- a/arch/arc/include/asm/ptrace.h +++ b/arch/arc/include/asm/ptrace.h @@ -100,6 +100,9 @@ struct callee_regs { #define in_syscall(regs) (regs->event & orig_r8_IS_SCALL) #define in_brkpt_trap(regs) (regs->event & orig_r8_IS_BRKPT) +#define syscall_wont_restart(regs) (regs->event |= orig_r8_IS_SCALL_RESTARTED) +#define syscall_restartable(regs) !(regs->event & orig_r8_IS_SCALL_RESTARTED) + #define current_pt_regs() \ ({ \ /* open-coded current_thread_info() */ \ |