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authorErnie Petrides <petrides@redhat.com>2006-12-07 02:14:09 +0100
committerAndi Kleen <andi@basil.nowhere.org>2006-12-07 02:14:09 +0100
commit103efcd9aac1de4da6a1477f2f3b9fcf35273a18 (patch)
treeac8e8a1f379a35cfaa96992fb3f8c69e1c88195e
parentc55d92d141b9c40c67db249de91f5c224eb49859 (diff)
[PATCH] x86-64: fix perms/range of vsyscall vma in /proc/*/maps
The final line of /proc/<pid>/maps on x86_64 for native 64-bit tasks shows an incorrect ending address and incorrect permissions. There is only a single page mapped in this vsyscall region, and it is accessible for both read and execute. The patch below fixes this. (Since 32-bit-compat tasks have a real vma with correct perms/range, no change is necessary for that scenario.) Before the patch, a "cat /proc/self/maps | tail -1" shows this: ffffffffff600000-ffffffffffe00000 ---p 00000000 [...] After the patch, this is the output: ffffffffff600000-ffffffffff601000 r-xp 00000000 [...] Signed-off-by: Ernie Petrides <petrides@redhat.com> Signed-off-by: Andi Kleen <ak@suse.de>
-rw-r--r--arch/x86_64/kernel/vsyscall.c1
-rw-r--r--arch/x86_64/mm/init.c7
-rw-r--r--include/asm-x86_64/vsyscall.h1
3 files changed, 6 insertions, 3 deletions
diff --git a/arch/x86_64/kernel/vsyscall.c b/arch/x86_64/kernel/vsyscall.c
index 92546c1526f..c3de9a09cd9 100644
--- a/arch/x86_64/kernel/vsyscall.c
+++ b/arch/x86_64/kernel/vsyscall.c
@@ -290,6 +290,7 @@ static void __init map_vsyscall(void)
extern char __vsyscall_0;
unsigned long physaddr_page0 = __pa_symbol(&__vsyscall_0);
+ /* Note that VSYSCALL_MAPPED_PAGES must agree with the code below. */
__set_fixmap(VSYSCALL_FIRST_PAGE, physaddr_page0, PAGE_KERNEL_VSYSCALL);
}
diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c
index 4c0c00ef3ca..2968b90ef8a 100644
--- a/arch/x86_64/mm/init.c
+++ b/arch/x86_64/mm/init.c
@@ -730,14 +730,15 @@ static __init int x8664_sysctl_init(void)
__initcall(x8664_sysctl_init);
#endif
-/* A pseudo VMAs to allow ptrace access for the vsyscall page. This only
+/* A pseudo VMA to allow ptrace access for the vsyscall page. This only
covers the 64bit vsyscall page now. 32bit has a real VMA now and does
not need special handling anymore. */
static struct vm_area_struct gate_vma = {
.vm_start = VSYSCALL_START,
- .vm_end = VSYSCALL_END,
- .vm_page_prot = PAGE_READONLY
+ .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES << PAGE_SHIFT),
+ .vm_page_prot = PAGE_READONLY_EXEC,
+ .vm_flags = VM_READ | VM_EXEC
};
struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
diff --git a/include/asm-x86_64/vsyscall.h b/include/asm-x86_64/vsyscall.h
index 01d1c17e284..05cb8dd200d 100644
--- a/include/asm-x86_64/vsyscall.h
+++ b/include/asm-x86_64/vsyscall.h
@@ -10,6 +10,7 @@ enum vsyscall_num {
#define VSYSCALL_START (-10UL << 20)
#define VSYSCALL_SIZE 1024
#define VSYSCALL_END (-2UL << 20)
+#define VSYSCALL_MAPPED_PAGES 1
#define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr))
#ifdef __KERNEL__