new helper: current_user_stack_pointer()

Cross-architecture equivalent of rdusp(); default is
user_stack_pointer(current_pt_regs()) - that works for almost all
platforms that have usp saved in pt_regs.  The only exception from
that is ia64 - we want memory stack, not the backing store for
register one.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-11-18 12:50:10 -05:00
parent 5208ba24e7
commit 1ca97bb541
7 changed files with 14 additions and 0 deletions

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@ -72,6 +72,7 @@ struct switch_stack {
#define user_mode(regs) (((regs)->ps & 8) != 0)
#define instruction_pointer(regs) ((regs)->pc)
#define profile_pc(regs) instruction_pointer(regs)
#define current_user_stack_pointer() rdusp()
#define task_pt_regs(task) \
((struct pt_regs *) (task_stack_page(task) + 2*PAGE_SIZE) - 1)

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@ -106,6 +106,7 @@ struct pt_regs {
#define arch_has_single_step() (1)
/* common code demands this function */
#define ptrace_disable(child) user_disable_single_step(child)
#define current_user_stack_pointer() rdusp()
extern int is_user_addr_valid(struct task_struct *child,
unsigned long start, unsigned long len);

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@ -10,6 +10,7 @@
#define PTRACE_SETREGS 13
#define profile_pc(regs) instruction_pointer(regs)
#define current_user_stack_pointer() rdusp()
#endif /* __KERNEL__ */

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@ -63,6 +63,7 @@ struct pt_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)
#define current_user_stack_pointer() rdusp()
#endif /* __KERNEL__ */
#endif /* __ASSEMBLY__ */
#endif /* _H8300_PTRACE_H */

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@ -78,6 +78,11 @@ static inline long regs_return_value(struct pt_regs *regs)
unsigned long __ip = instruction_pointer(regs); \
(__ip & ~3UL) + ((__ip & 3UL) << 2); \
})
/*
* Why not default? Because user_stack_pointer() on ia64 gives register
* stack backing store instead...
*/
#define current_user_stack_pointer() (current_pt_regs()->r12)
/* given a pointer to a task_struct, return the user's pt_regs */
# define task_pt_regs(t) (((struct pt_regs *) ((char *) (t) + IA64_STK_OFFSET)) - 1)

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@ -15,6 +15,7 @@
#define profile_pc(regs) instruction_pointer(regs)
#define current_pt_regs() \
(struct pt_regs *)((char *)current_thread_info() + THREAD_SIZE) - 1
#define current_user_stack_pointer() rdusp()
#define arch_has_single_step() (1)

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@ -342,6 +342,10 @@ static inline void user_single_step_siginfo(struct task_struct *tsk,
#define signal_pt_regs() task_pt_regs(current)
#endif
#ifndef current_user_stack_pointer
#define current_user_stack_pointer() user_stack_pointer(current_pt_regs())
#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);