From: ebiederm@xmission.com (Eric W. Biederman)
To: <linux-kernel@vger.kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Oleg Nesterov <oleg@redhat.com>,
Al Viro <viro@ZenIV.linux.org.uk>, <linux-api@vger.kernel.org>,
Kees Cook <keescook@chromium.org>,
David Miller <davem@davemloft.net>,
sparclinux@vger.kernel.org, linux-ia64@vger.kernel.org
Subject: [PATCH 2/6] ptrace: Remove the unnecessary arguments from arch_ptrace_stop
Date: Fri, 24 Sep 2021 10:22:00 -0500 [thread overview]
Message-ID: <87k0j6q9rb.fsf@disp2133> (raw)
In-Reply-To: <87v92qx2c6.fsf@disp2133> (Eric W. Biederman's message of "Thu, 23 Sep 2021 19:08:09 -0500")
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
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
Resent because my little one distracted me as I was sending this last
night and I did not manage to copy the sparc and ia64 folks.
arch/ia64/include/asm/ptrace.h | 4 ++--
arch/sparc/include/asm/ptrace.h | 8 ++++----
include/linux/ptrace.h | 22 +++++++++-------------
kernel/signal.c | 4 ++--
4 files changed, 17 insertions(+), 21 deletions(-)
diff --git a/arch/ia64/include/asm/ptrace.h b/arch/ia64/include/asm/ptrace.h
index 08179135905c..f15504f75f10 100644
--- a/arch/ia64/include/asm/ptrace.h
+++ b/arch/ia64/include/asm/ptrace.h
@@ -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 *);
diff --git a/arch/sparc/include/asm/ptrace.h b/arch/sparc/include/asm/ptrace.h
index 71dd82b43cc5..d1419e669027 100644
--- a/arch/sparc/include/asm/ptrace.h
+++ b/arch/sparc/include/asm/ptrace.h
@@ -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() \
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index b5ebf6c01292..8aee2945ff08 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -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
diff --git a/kernel/signal.c b/kernel/signal.c
index 9f2dc9cf3208..c9759ff2cb43 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -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(¤t->sighand->siglock);
- arch_ptrace_stop(exit_code, info);
+ arch_ptrace_stop();
spin_lock_irq(¤t->sighand->siglock);
}
--
2.20.1
prev parent reply other threads:[~2021-09-24 15:22 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-24 0:08 [PATCH 0/6] per signal_struct coredumps Eric W. Biederman
2021-09-24 0:09 ` [PATCH 1/6] signal: Remove the bogus sigkill_pending in ptrace_stop Eric W. Biederman
2021-09-24 15:22 ` Kees Cook
2021-09-24 15:48 ` Eric W. Biederman
2021-09-24 19:06 ` Kees Cook
2021-09-24 0:10 ` [PATCH 2/6] ptrace: Remove the unnecessary arguments from arch_ptrace_stop Eric W. Biederman
2021-09-24 15:26 ` Kees Cook
2021-09-24 0:10 ` [PATCH 3/6] exec: Check for a pending fatal signal instead of core_state Eric W. Biederman
2021-09-24 15:38 ` Kees Cook
2021-09-24 0:11 ` [PATCH 4/6] exit: Factor coredump_exit_mm out of exit_mm Eric W. Biederman
2021-09-24 18:28 ` Kees Cook
2021-09-24 0:11 ` [PATCH 5/6] coredump: Don't perform any cleanups before dumping core Eric W. Biederman
2021-09-24 18:51 ` Kees Cook
2021-09-24 21:28 ` Eric W. Biederman
2021-09-24 21:41 ` Kees Cook
2021-09-24 0:12 ` [PATCH 6/6] coredump: Limit coredumps to a single thread group Eric W. Biederman
2021-09-24 18:56 ` Kees Cook
2021-10-06 17:03 ` Eric W. Biederman
2021-11-19 16:03 ` Kyle Huey
2021-11-19 17:38 ` Eric W. Biederman
2021-09-24 5:59 ` [PATCH 0/6] per signal_struct coredumps Kees Cook
2021-09-24 14:00 ` Eric W. Biederman
2021-09-24 15:22 ` Eric W. Biederman [this message]
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