[PATCH] x86, vdso32: fix out of memory handling setup vDSO

From: Stefani Seibold
Date: Thu Mar 20 2014 - 03:46:27 EST


This patch add a correct out of memory handling for setup a 32 bit vDSO.

The patch is against tip commit 4e40112c4ff6a577dd06d92b2a54cdf06265bf74

Signed-off-by: Stefani Seibold <stefani@xxxxxxxxxxx>
---
arch/x86/vdso/vdso32-setup.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 0bc363a..e1171c2 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -134,8 +134,14 @@ int __init sysenter_setup(void)
}

vdso32_size = (vdso_len + PAGE_SIZE - 1) / PAGE_SIZE;
- vdso32_pages = kmalloc(sizeof(*vdso32_pages) * vdso32_size, GFP_ATOMIC);
+
+ vdso32_pages = kmalloc(sizeof(*vdso32_pages) * vdso32_size, GFP_ATOMIC);
+ if (!vdso32_pages)
+ goto fail;
+
vdso_pages = kmalloc(VDSO_OFFSET(vdso32_size), GFP_ATOMIC);
+ if (!vdso_pages)
+ goto fail;

for(i = 0; i != vdso32_size; ++i)
vdso32_pages[i] = virt_to_page(vdso_pages + VDSO_OFFSET(i));
@@ -144,6 +150,12 @@ int __init sysenter_setup(void)
patch_vdso32(vdso_pages, vdso_len);

return 0;
+fail:
+ kfree(vdso32_pages);
+ kfree(vdso_pages);
+ vdso32_size = 0;
+
+ return -ENOMEM;
}

/* Setup a VMA at program startup for the vsyscall page */
@@ -162,6 +174,9 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
if (vdso_enabled != 1) /* Other values all mean "disabled" */
return 0;

+ if (!vdso32_size)
+ return 0;
+
down_write(&mm->mmap_sem);

addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
--
1.9.0

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