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authorAl Viro <viro@zeniv.linux.org.uk>2012-11-05 13:00:27 -0500
committerAl Viro <viro@zeniv.linux.org.uk>2012-11-29 00:01:23 -0500
commit22062a96300dabfef93368a28c34bdf35c9b8308 (patch)
tree6e04303c437911d21079a34ac0853137eeb91f8b
parent4f4202fe5ae9a43e59303f20d700571f695d7b1b (diff)
new helper: signal_pt_regs()
Always equal to task_pt_regs(current); defined only when we are in signal delivery. It may be different from current_pt_regs() - e.g. architectures like m68k may have pt_regs location on exception different from that on a syscall and signals (just as ptrace handling) may happen on exceptions as well as on syscalls. When they are equal, it's often better to have signal_pt_regs defined (in asm/ptrace.h) as current_pt_regs - that tends to be optimized better than default would be. However, optimisation is the only reason why we might want an arch-specific definition; if current_pt_regs() and task_pt_regs(current) have different values, the latter one is right. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--arch/alpha/include/asm/ptrace.h1
-rw-r--r--arch/h8300/include/asm/ptrace.h1
-rw-r--r--include/linux/ptrace.h9
3 files changed, 11 insertions, 0 deletions
diff --git a/arch/alpha/include/asm/ptrace.h b/arch/alpha/include/asm/ptrace.h
index b87755a1955..b4c5b2fbb64 100644
--- a/arch/alpha/include/asm/ptrace.h
+++ b/arch/alpha/include/asm/ptrace.h
@@ -78,6 +78,7 @@ struct switch_stack {
#define current_pt_regs() \
((struct pt_regs *) ((char *)current_thread_info() + 2*PAGE_SIZE) - 1)
+#define signal_pt_regs current_pt_regs
#define force_successful_syscall_return() (current_pt_regs()->r0 = 0)
diff --git a/arch/h8300/include/asm/ptrace.h b/arch/h8300/include/asm/ptrace.h
index 00502a61bf0..7468589a128 100644
--- a/arch/h8300/include/asm/ptrace.h
+++ b/arch/h8300/include/asm/ptrace.h
@@ -62,6 +62,7 @@ struct pt_regs {
#define profile_pc(regs) instruction_pointer(regs)
#define current_pt_regs() ((struct pt_regs *) \
(THREAD_SIZE + (unsigned long)current_thread_info()) - 1)
+#define signal_pt_regs() ((struct pt_regs *)current->thread.esp0)
#endif /* __KERNEL__ */
#endif /* __ASSEMBLY__ */
#endif /* _H8300_PTRACE_H */
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index 7aefbae2452..b8e6dcec78a 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -333,6 +333,15 @@ static inline void user_single_step_siginfo(struct task_struct *tsk,
#define ptrace_signal_deliver(regs, cookie) do { } while (0)
#endif
+/*
+ * unlike current_pt_regs(), this one is equal to task_pt_regs(current)
+ * on *all* architectures; the only reason to have a per-arch definition
+ * is optimisation.
+ */
+#ifndef signal_pt_regs
+#define signal_pt_regs() task_pt_regs(current)
+#endif
+
extern int task_current_syscall(struct task_struct *target, long *callno,
unsigned long args[6], unsigned int maxargs,
unsigned long *sp, unsigned long *pc);