Map the vsyscall page with _PAGE_USER
This needs to happen early in kaiser_pagetable_walk(), before the
hierarchy is established so that _PAGE_USER permission can be really
set.
A proper fix would be to teach kaiser_pagetable_walk() to update those
permissions but the vsyscall page is the only exception here so ...
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/arch/x86/include/asm/vsyscall.h b/arch/x86/include/asm/vsyscall.h
index 6ba66ee..4865e10 100644
--- a/arch/x86/include/asm/vsyscall.h
+++ b/arch/x86/include/asm/vsyscall.h
@@ -12,12 +12,14 @@
* Returns true if handled.
*/
extern bool emulate_vsyscall(struct pt_regs *regs, unsigned long address);
+extern bool vsyscall_enabled(void);
#else
static inline void map_vsyscall(void) {}
static inline bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
{
return false;
}
+static inline bool vsyscall_enabled(void) { return false; }
#endif
#endif /* _ASM_X86_VSYSCALL_H */