x86, fs: Fix x86 procfs stack information for threads on 64-bit (89240ba0) · Commits · 戴 / test

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>

arch/x86/include/asm/processor.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -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,

arch/x86/kernel/process_64.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -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);
		}

fs/compat.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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;

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