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Commit 89240ba059ca468ae7a8346edf7f95082458c2fc

Authored by Stefani Seibold
Committed by Ingo Molnar
1 parent 1d87cff407
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

x86, fs: Fix x86 procfs stack information for threads on 64-bit 

This patch fixes two issues in the procfs stack information on
x86-64 linux.

The 32 bit loader compat_do_execve did not store stack
start. (this was figured out by Alexey Dobriyan).

The stack information on a x64_64 kernel always shows 0 kbyte
stack usage, because of a missing implementation of the KSTK_ESP
macro which always returned -1.

The new implementation now returns the right value.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Cc: Americo Wang <xiyou.wangcong@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <1257240160.4889.24.camel@wall-e>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Showing 3 changed files with 8 additions and 1 deletions Side-by-side Diff

arch/x86/include/asm/processor.h
Diff comments   View file @ 89240ba
... ... @@ -1000,7 +1000,7 @@
1000 1000 #define thread_saved_pc(t) (*(unsigned long *)((t)->thread.sp - 8))
1001 1001  
1002 1002 #define task_pt_regs(tsk) ((struct pt_regs *)(tsk)->thread.sp0 - 1)
1003   -#define KSTK_ESP(tsk) -1 /* sorry. doesn't work for syscall. */
  1003 +extern unsigned long KSTK_ESP(struct task_struct *task);
1004 1004 #endif /* CONFIG_X86_64 */
1005 1005  
1006 1006 extern void start_thread(struct pt_regs *regs, unsigned long new_ip,
arch/x86/kernel/process_64.c
Diff comments   View file @ 89240ba
... ... @@ -663,4 +663,10 @@
663 663 {
664 664 return do_arch_prctl(current, code, addr);
665 665 }
  666 +
  667 +unsigned long KSTK_ESP(struct task_struct *task)
  668 +{
  669 + return (test_tsk_thread_flag(task, TIF_IA32)) ?
  670 + (task_pt_regs(task)->sp) : ((task)->thread.usersp);
  671 +}
... ... @@ -1532,6 +1532,8 @@
1532 1532 if (retval < 0)
1533 1533 goto out;
1534 1534  
  1535 + current->stack_start = current->mm->start_stack;
  1536 +
1535 1537 /* execve succeeded */
1536 1538 current->fs->in_exec = 0;
1537 1539 current->in_execve = 0;