mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

ptrace: Remove the unnecessary arguments from arch_ptrace_stop 

Both arch_ptrace_stop_needed and arch_ptrace_stop are called with an
exit_code and a siginfo structure.  Neither argument is used by any of
the implementations so just remove the unneeded arguments.

The two arechitectures that implement arch_ptrace_stop are ia64 and
sparc.  Both architectures flush their register stacks before a
ptrace_stack so that all of the register information can be accessed
by debuggers.

As the question of if a register stack needs to be flushed is
independent of why ptrace is stopping not needing arguments make sense.

Cc: David Miller <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Link: https://lkml.kernel.org/r/87lf3mx290.fsf@disp2133
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
This commit is contained in:
Eric W. Biederman 2021-09-02 16:10:11 -05:00
parent 7d613f9f72
commit 4f627af8e6
4 changed files with 17 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/ia64/include/asm/ptrace.h
View File

@ -129,9 +129,9 @@ static inline long regs_return_value(struct pt_regs *regs)
extern void ia64_decrement_ip (struct pt_regs *pt);
extern void ia64_ptrace_stop(void);
#define arch_ptrace_stop(code, info) \
#define arch_ptrace_stop() \
ia64_ptrace_stop()
#define arch_ptrace_stop_needed(code, info) \
#define arch_ptrace_stop_needed() \
(!test_thread_flag(TIF_RESTORE_RSE))
extern void ptrace_attach_sync_user_rbs (struct task_struct *);

8
arch/sparc/include/asm/ptrace.h
View File

@ -26,12 +26,12 @@ static inline bool pt_regs_clear_syscall(struct pt_regs *regs)
return (regs->tstate &= ~TSTATE_SYSCALL);
}
#define arch_ptrace_stop_needed(exit_code, info) \
#define arch_ptrace_stop_needed() \
({ flush_user_windows(); \
get_thread_wsaved() != 0; \
})
#define arch_ptrace_stop(exit_code, info) \
#define arch_ptrace_stop() \
synchronize_user_stack()
#define current_pt_regs() \
@ -129,12 +129,12 @@ static inline bool pt_regs_clear_syscall(struct pt_regs *regs)
return (regs->psr &= ~PSR_SYSCALL);
}
#define arch_ptrace_stop_needed(exit_code, info) \
#define arch_ptrace_stop_needed() \
({ flush_user_windows(); \
current_thread_info()->w_saved != 0; \
})
#define arch_ptrace_stop(exit_code, info) \
#define arch_ptrace_stop() \
synchronize_user_stack()
#define current_pt_regs() \

22
include/linux/ptrace.h
View File

@ -362,29 +362,25 @@ static inline void user_single_step_report(struct pt_regs *regs)
#ifndef arch_ptrace_stop_needed
/**
* arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
* @code: current->exit_code value ptrace will stop with
* @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
*
* This is called with the siglock held, to decide whether or not it's
* necessary to release the siglock and call arch_ptrace_stop() with the
* same @code and @info arguments. It can be defined to a constant if
* arch_ptrace_stop() is never required, or always is. On machines where
* this makes sense, it should be defined to a quick test to optimize out
* calling arch_ptrace_stop() when it would be superfluous. For example,
* if the thread has not been back to user mode since the last stop, the
* thread state might indicate that nothing needs to be done.
* necessary to release the siglock and call arch_ptrace_stop(). It can be
* defined to a constant if arch_ptrace_stop() is never required, or always
* is. On machines where this makes sense, it should be defined to a quick
* test to optimize out calling arch_ptrace_stop() when it would be
* superfluous. For example, if the thread has not been back to user mode
* since the last stop, the thread state might indicate that nothing needs
* to be done.
*
* This is guaranteed to be invoked once before a task stops for ptrace and
* may include arch-specific operations necessary prior to a ptrace stop.
*/
#define arch_ptrace_stop_needed(code, info) (0)
#define arch_ptrace_stop_needed() (0)
#endif
#ifndef arch_ptrace_stop
/**
* arch_ptrace_stop - Do machine-specific work before stopping for ptrace
* @code: current->exit_code value ptrace will stop with
* @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
*
* This is called with no locks held when arch_ptrace_stop_needed() has
* just returned nonzero. It is allowed to block, e.g. for user memory
@ -394,7 +390,7 @@ static inline void user_single_step_report(struct pt_regs *regs)
* we only do it when the arch requires it for this particular stop, as
* indicated by arch_ptrace_stop_needed().
*/
#define arch_ptrace_stop(code, info) do { } while (0)
#define arch_ptrace_stop() do { } while (0)
#endif
#ifndef current_pt_regs

4
kernel/signal.c
View File

@ -2200,7 +2200,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, kernel_siginfo_t
{
bool gstop_done = false;
if (arch_ptrace_stop_needed(exit_code, info)) {
if (arch_ptrace_stop_needed()) {
/*
* The arch code has something special to do before a
* ptrace stop. This is allowed to block, e.g. for faults
@ -2210,7 +2210,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, kernel_siginfo_t
* any signal bookkeeping like checking group_stop_count.
*/
spin_unlock_irq(&current->sighand->siglock);
arch_ptrace_stop(exit_code, info);
arch_ptrace_stop();
spin_lock_irq(&current->sighand->siglock);
}