diff options
| author | Ernie Petrides <petrides@redhat.com> | 2006-12-07 02:14:09 +0100 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2006-12-07 02:14:09 +0100 |
| commit | 103efcd9aac1de4da6a1477f2f3b9fcf35273a18 (patch) | |
| tree | ac8e8a1f379a35cfaa96992fb3f8c69e1c88195e | |
| parent | c55d92d141b9c40c67db249de91f5c224eb49859 (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.c | 1 | ||||
| -rw-r--r-- | arch/x86_64/mm/init.c | 7 | ||||
| -rw-r--r-- | include/asm-x86_64/vsyscall.h | 1 |
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__ |