The following commit has been merged in the linux branch: commit 89240ba059ca468ae7a8346edf7f95082458c2fc Author: Stefani Seibold stefani@seibold.net Date: Tue Nov 3 10:22:40 2009 +0100

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

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index c3429e8..c978648 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -1000,7 +1000,7 @@ extern unsigned long thread_saved_pc(struct task_struct *tsk); #define thread_saved_pc(t) (*(unsigned long *)((t)->thread.sp - 8))

#define task_pt_regs(tsk) ((struct pt_regs *)(tsk)->thread.sp0 - 1) -#define KSTK_ESP(tsk) -1 /* sorry. doesn't work for syscall. */ +extern unsigned long KSTK_ESP(struct task_struct *task); #endif /* CONFIG_X86_64 */

extern void start_thread(struct pt_regs *regs, unsigned long new_ip, diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index ad535b6..eb62cbc 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -664,3 +664,8 @@ long sys_arch_prctl(int code, unsigned long addr) return do_arch_prctl(current, code, addr); }

+unsigned long KSTK_ESP(struct task_struct *task) +{ + return (test_tsk_thread_flag(task, TIF_IA32)) ? + (task_pt_regs(task)->sp) : ((task)->thread.usersp); +} diff --git a/fs/compat.c b/fs/compat.c index d576b55..6c19040 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -1532,6 +1532,8 @@ int compat_do_execve(char * filename, if (retval < 0) goto out;

+ current->stack_start = current->mm->start_stack; + /* execve succeeded */ current->fs->in_exec = 0; current->in_execve = 0;