diff options
| author | Vineet Gupta <vgupta@synopsys.com> | 2013-02-11 20:01:24 +0530 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2013-02-15 23:15:49 +0530 |
| commit | 5c39c0ab5e862cf71cda1fc39a5cedd4e2f18c6e (patch) | |
| tree | 5241b832c2e64f581b55bb8c56bf3cb49836423b /arch/arc/kernel | |
| parent | c3581039b6c51a778a70accec53a9bb7ad9a4d32 (diff) | |
ARC: [Review] Preparing to fix incorrect syscall restarts due to signals
To avoid multiple syscall restarts (multiple signals) or no restart at
all (sigreturn), we need just an extra bit of state "literally 1 bit" in
struct pt_regs. orig_r8 is the best place to do this, however given the
way it is encoded currently, we can't add anything simplistically.
Current orig_r8:
* syscalls -> 1 to NR_SYSCALLS
* Exceptions -> NR_SYSCALLS + 1
* Break-point-> NR_SYSCALLS + 2
In new scheme it is a bit-field
* lower short word contains the exact event type (and a new bit to represent
restart semantics : if syscall was already / can't be restarted)
* upper short word optionally containing the syscall num - needed by
likes of tracehooks etc
This patch only changes how orig_r8 is organised and nothing should
change behaviourily.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Diffstat (limited to 'arch/arc/kernel')
| -rw-r--r-- | arch/arc/kernel/asm-offsets.c | 2 | ||||
| -rw-r--r-- | arch/arc/kernel/entry.S | 4 |
2 files changed, 3 insertions, 3 deletions
diff --git a/arch/arc/kernel/asm-offsets.c b/arch/arc/kernel/asm-offsets.c index 64b2c2fa7b5..d7770cc9aee 100644 --- a/arch/arc/kernel/asm-offsets.c +++ b/arch/arc/kernel/asm-offsets.c @@ -46,7 +46,7 @@ int main(void) BLANK(); DEFINE(PT_status32, offsetof(struct pt_regs, status32)); - DEFINE(PT_orig_r8, offsetof(struct pt_regs, orig_r8)); + DEFINE(PT_orig_r8, offsetof(struct pt_regs, orig_r8_word)); DEFINE(PT_sp, offsetof(struct pt_regs, sp)); DEFINE(PT_r0, offsetof(struct pt_regs, r0)); DEFINE(PT_r1, offsetof(struct pt_regs, r1)); diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S index d625b77c14b..ce8670da830 100644 --- a/arch/arc/kernel/entry.S +++ b/arch/arc/kernel/entry.S @@ -350,8 +350,8 @@ ARC_EXIT EV_Extension trap_with_param: - ;make sure orig_r8 is a positive value - st NR_syscalls + 2, [sp, PT_orig_r8] + ; stop_pc info by gdb needs this info + st orig_r8_IS_BRKPT, [sp, PT_orig_r8] mov r0, r12 lr r1, [efa] |