[PATCH] powerpc vdso updates
This patch cleans up some locking & error handling in the ppc vdso and
moves the vdso base pointer from the thread struct to the mm context
where it more logically belongs. It brings the powerpc implementation
closer to Ingo's new x86 one and also adds an arch_vma_name() function
allowing to print [vsdo] in /proc/<pid>/maps if Ingo's x86 vdso patch is
also applied.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 01e3c08..22f0789 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -757,10 +757,10 @@
/* Save user registers on the stack */
frame = &rt_sf->uc.uc_mcontext;
- if (vdso32_rt_sigtramp && current->thread.vdso_base) {
+ if (vdso32_rt_sigtramp && current->mm->context.vdso_base) {
if (save_user_regs(regs, frame, 0))
goto badframe;
- regs->link = current->thread.vdso_base + vdso32_rt_sigtramp;
+ regs->link = current->mm->context.vdso_base + vdso32_rt_sigtramp;
} else {
if (save_user_regs(regs, frame, __NR_rt_sigreturn))
goto badframe;
@@ -1029,10 +1029,10 @@
|| __put_user(sig, &sc->signal))
goto badframe;
- if (vdso32_sigtramp && current->thread.vdso_base) {
+ if (vdso32_sigtramp && current->mm->context.vdso_base) {
if (save_user_regs(regs, &frame->mctx, 0))
goto badframe;
- regs->link = current->thread.vdso_base + vdso32_sigtramp;
+ regs->link = current->mm->context.vdso_base + vdso32_sigtramp;
} else {
if (save_user_regs(regs, &frame->mctx, __NR_sigreturn))
goto badframe;
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 27f65b9..23ba69c 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -394,8 +394,8 @@
current->thread.fpscr.val = 0;
/* Set up to return from userspace. */
- if (vdso64_rt_sigtramp && current->thread.vdso_base) {
- regs->link = current->thread.vdso_base + vdso64_rt_sigtramp;
+ if (vdso64_rt_sigtramp && current->mm->context.vdso_base) {
+ regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp;
} else {
err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
if (err)
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index 573afb6..bc3e15b 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -223,6 +223,7 @@
struct vm_area_struct *vma;
unsigned long vdso_pages;
unsigned long vdso_base;
+ int rc;
#ifdef CONFIG_PPC64
if (test_thread_flag(TIF_32BIT)) {
@@ -237,20 +238,13 @@
vdso_base = VDSO32_MBASE;
#endif
- current->thread.vdso_base = 0;
+ current->mm->context.vdso_base = 0;
/* vDSO has a problem and was disabled, just don't "enable" it for the
* process
*/
if (vdso_pages == 0)
return 0;
-
- vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
- if (vma == NULL)
- return -ENOMEM;
-
- memset(vma, 0, sizeof(*vma));
-
/* Add a page to the vdso size for the data page */
vdso_pages ++;
@@ -259,17 +253,23 @@
* at vdso_base which is the "natural" base for it, but we might fail
* and end up putting it elsewhere.
*/
+ down_write(&mm->mmap_sem);
vdso_base = get_unmapped_area(NULL, vdso_base,
vdso_pages << PAGE_SHIFT, 0, 0);
- if (vdso_base & ~PAGE_MASK) {
- kmem_cache_free(vm_area_cachep, vma);
- return (int)vdso_base;
+ if (IS_ERR_VALUE(vdso_base)) {
+ rc = vdso_base;
+ goto fail_mmapsem;
}
- current->thread.vdso_base = vdso_base;
+ /* Allocate a VMA structure and fill it up */
+ vma = kmem_cache_zalloc(vm_area_cachep, SLAB_KERNEL);
+ if (vma == NULL) {
+ rc = -ENOMEM;
+ goto fail_mmapsem;
+ }
vma->vm_mm = mm;
- vma->vm_start = current->thread.vdso_base;
+ vma->vm_start = vdso_base;
vma->vm_end = vma->vm_start + (vdso_pages << PAGE_SHIFT);
/*
@@ -282,23 +282,38 @@
* It's fine to use that for setting breakpoints in the vDSO code
* pages though
*/
- vma->vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
+ vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC;
vma->vm_flags |= mm->def_flags;
vma->vm_page_prot = protection_map[vma->vm_flags & 0x7];
vma->vm_ops = &vdso_vmops;
- down_write(&mm->mmap_sem);
- if (insert_vm_struct(mm, vma)) {
- up_write(&mm->mmap_sem);
- kmem_cache_free(vm_area_cachep, vma);
- return -ENOMEM;
- }
+ /* Insert new VMA */
+ rc = insert_vm_struct(mm, vma);
+ if (rc)
+ goto fail_vma;
+
+ /* Put vDSO base into mm struct and account for memory usage */
+ current->mm->context.vdso_base = vdso_base;
mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
up_write(&mm->mmap_sem);
-
return 0;
+
+ fail_vma:
+ kmem_cache_free(vm_area_cachep, vma);
+ fail_mmapsem:
+ up_write(&mm->mmap_sem);
+ return rc;
}
+const char *arch_vma_name(struct vm_area_struct *vma)
+{
+ if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
+ return "[vdso]";
+ return NULL;
+}
+
+
+
static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
unsigned long *size)
{
diff --git a/include/asm-powerpc/elf.h b/include/asm-powerpc/elf.h
index 94d228f..319655c 100644
--- a/include/asm-powerpc/elf.h
+++ b/include/asm-powerpc/elf.h
@@ -294,7 +294,7 @@
NEW_AUX_ENT(AT_DCACHEBSIZE, dcache_bsize); \
NEW_AUX_ENT(AT_ICACHEBSIZE, icache_bsize); \
NEW_AUX_ENT(AT_UCACHEBSIZE, ucache_bsize); \
- VDSO_AUX_ENT(AT_SYSINFO_EHDR, current->thread.vdso_base) \
+ VDSO_AUX_ENT(AT_SYSINFO_EHDR, current->mm->context.vdso_base) \
} while (0)
/* PowerPC64 relocations defined by the ABIs */
diff --git a/include/asm-powerpc/mmu.h b/include/asm-powerpc/mmu.h
index 31f7219..96e47d1 100644
--- a/include/asm-powerpc/mmu.h
+++ b/include/asm-powerpc/mmu.h
@@ -360,6 +360,7 @@
#ifdef CONFIG_HUGETLB_PAGE
u16 low_htlb_areas, high_htlb_areas;
#endif
+ unsigned long vdso_base;
} mm_context_t;
diff --git a/include/asm-powerpc/page.h b/include/asm-powerpc/page.h
index ae610b6..a315d0c 100644
--- a/include/asm-powerpc/page.h
+++ b/include/asm-powerpc/page.h
@@ -192,6 +192,9 @@
struct page *p);
extern int page_is_ram(unsigned long pfn);
+struct vm_area_struct;
+extern const char *arch_vma_name(struct vm_area_struct *vma);
+
#include <asm-generic/memory_model.h>
#endif /* __ASSEMBLY__ */
diff --git a/include/asm-powerpc/processor.h b/include/asm-powerpc/processor.h
index 93f83ef..d5c7ef1 100644
--- a/include/asm-powerpc/processor.h
+++ b/include/asm-powerpc/processor.h
@@ -153,7 +153,6 @@
unsigned long start_tb; /* Start purr when proc switched in */
unsigned long accum_tb; /* Total accumilated purr for process */
#endif
- unsigned long vdso_base; /* base of the vDSO library */
unsigned long dabr; /* Data address breakpoint register */
#ifdef CONFIG_ALTIVEC
/* Complete AltiVec register set */
