linux-kernel - [tip:x86/fpu] x86: copy_thread: Don't nullify ->ptrace

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Date:	Tue, 2 Sep 2014 15:19:57 -0700
From:	tip-bot for Oleg Nesterov <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...nel.org,
	oleg@...hat.com, tglx@...utronix.de, hpa@...ux.intel.com
Subject: [tip:x86/fpu] x86: copy_thread: Don't nullify ->ptrace_bps twice

Commit-ID:  6f46b3aef0031c08a7b439d63013dad2aeb093b2
Gitweb:     http://git.kernel.org/tip/6f46b3aef0031c08a7b439d63013dad2aeb093b2
Author:     Oleg Nesterov <oleg@...hat.com>
AuthorDate: Tue, 2 Sep 2014 19:57:33 +0200
Committer:  H. Peter Anvin <hpa@...ux.intel.com>
CommitDate: Tue, 2 Sep 2014 14:51:17 -0700

x86: copy_thread: Don't nullify ->ptrace_bps twice

Both 32bit and 64bit versions of copy_thread() do memset(ptrace_bps)
twice for no reason, kill the 2nd memset().

Signed-off-by: Oleg Nesterov <oleg@...hat.com>
Link: http://lkml.kernel.org/r/20140902175733.GA21676@redhat.com
Signed-off-by: H. Peter Anvin <hpa@...ux.intel.com>
---
 arch/x86/kernel/process_32.c | 4 +---
 arch/x86/kernel/process_64.c | 2 --
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index c73b3c1..8f3ebfe 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -138,6 +138,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
 
 	p->thread.sp = (unsigned long) childregs;
 	p->thread.sp0 = (unsigned long) (childregs+1);
+	memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
 
 	if (unlikely(p->flags & PF_KTHREAD)) {
 		/* kernel thread */
@@ -153,7 +154,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
 		childregs->cs = __KERNEL_CS | get_kernel_rpl();
 		childregs->flags = X86_EFLAGS_IF | X86_EFLAGS_FIXED;
 		p->thread.io_bitmap_ptr = NULL;
-		memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
 		return 0;
 	}
 	*childregs = *current_pt_regs();
@@ -168,8 +168,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
 	tsk = current;
 	err = -ENOMEM;
 
-	memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
-
 	if (unlikely(test_tsk_thread_flag(tsk, TIF_IO_BITMAP))) {
 		p->thread.io_bitmap_ptr = kmemdup(tsk->thread.io_bitmap_ptr,
 						IO_BITMAP_BYTES, GFP_KERNEL);
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 593257d..3ed4a68 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -192,8 +192,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
 		childregs->sp = sp;
 
 	err = -ENOMEM;
-	memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
-
 	if (unlikely(test_tsk_thread_flag(me, TIF_IO_BITMAP))) {
 		p->thread.io_bitmap_ptr = kmemdup(me->thread.io_bitmap_ptr,
 						  IO_BITMAP_BYTES, GFP_KERNEL);
--
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