From f2053f1a7bf6005b4e81826b1ac8d0b4117c4cf0 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Mon, 21 Sep 2009 16:57:40 +0000 Subject: [PATCH] powerpc/perf_counter: Fix vdso detection perf_counter uses arch_vma_name() to detect a vdso region which in turn uses current->mm->context.vdso_base. We need to initialise this before doing the mmap or else we fail to detect the vdso. Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/vdso.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c index 3faaf29bdb29..94e2df3cae07 100644 --- a/arch/powerpc/kernel/vdso.c +++ b/arch/powerpc/kernel/vdso.c @@ -240,6 +240,13 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) goto fail_mmapsem; } + /* + * Put vDSO base into mm struct. We need to do this before calling + * install_special_mapping or the perf counter mmap tracking code + * will fail to recognise it as a vDSO (since arch_vma_name fails). + */ + current->mm->context.vdso_base = vdso_base; + /* * our vma flags don't have VM_WRITE so by default, the process isn't * allowed to write those pages. @@ -260,11 +267,10 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC| VM_ALWAYSDUMP, vdso_pagelist); - if (rc) + if (rc) { + current->mm->context.vdso_base = 0; goto fail_mmapsem; - - /* Put vDSO base into mm struct */ - current->mm->context.vdso_base = vdso_base; + } up_write(&mm->mmap_sem); return 0; -- GitLab