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authorChuck Ebbert <76306.1226@compuserve.com>2006-06-26 13:59:50 +0200
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-26 10:48:22 -0700
commit03fdc2c277afdbd217eccd1ce0cfeff77ebd8b77 (patch)
treee7264520754eed7b71296c839dff36d9270ee516 /arch/x86_64
parent6bfa9bb5195c68f75bd3937e4d77cb0bfe852d0d (diff)
[PATCH] x86_64: enlarge window for stack growth
Allow stack growth so the 'enter' instruction works. Also fixes problem in compat_sys_kexec_load() which could allocate more than 128 bytes using compat_alloc_user_space(). Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/x86_64')
-rw-r--r--arch/x86_64/mm/fault.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/x86_64/mm/fault.c b/arch/x86_64/mm/fault.c
index 64728898f86..4968a71df4a 100644
--- a/arch/x86_64/mm/fault.c
+++ b/arch/x86_64/mm/fault.c
@@ -410,8 +410,10 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
if (!(vma->vm_flags & VM_GROWSDOWN))
goto bad_area;
if (error_code & 4) {
- // XXX: align red zone size with ABI
- if (address + 128 < regs->rsp)
+ /* Allow userspace just enough access below the stack pointer
+ * to let the 'enter' instruction work.
+ */
+ if (address + 65536 + 32 * sizeof(unsigned long) < regs->rsp)
goto bad_area;
}
if (expand_stack(vma, address))