Commit 22062a96 authored by Al Viro's avatar Al Viro
Browse files

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: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 4f4202fe

arch/alpha/include/asm/ptrace.h

+1 −0
Original line number Diff line number Diff line
@@ -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)

arch/h8300/include/asm/ptrace.h

+1 −0
Original line number Diff line number Diff line
@@ -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 */

include/linux/ptrace.h

+9 −0
Original line number Diff line number Diff line
@@ -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);

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