diff options
| author |   Andy Lutomirski <luto@kernel.org> | 2019-06-26 21:45:04 -0700 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2019-06-28 00:04:39 +0200 |
| commit | 918ce325098a4eef99daad7b6796da33cebaf03a (patch) | |
| tree | 350e3c5a1bae0686cb0050a466b85917792e4b7f /arch/x86/mm | |
| parent | x86/vsyscall: Add a new vsyscall=xonly mode (diff) | |
| download | linux-dev-918ce325098a4eef99daad7b6796da33cebaf03a.tar.xz linux-dev-918ce325098a4eef99daad7b6796da33cebaf03a.zip | |
x86/vsyscall: Show something useful on a read fault
Just segfaulting the application when it tries to read the vsyscall page in
xonly mode is not helpful for those who need to debug it.
Emit a hint.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jann Horn <jannh@google.com>
Link: https://lkml.kernel.org/r/8016afffe0eab497be32017ad7f6f7030dc3ba66.1561610354.git.luto@kernel.org
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/fault.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 46df4c6aae46..288a5462076f 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1369,16 +1369,15 @@ void do_user_addr_fault(struct pt_regs *regs, #ifdef CONFIG_X86_64 /* - * Instruction fetch faults in the vsyscall page might need - * emulation. The vsyscall page is at a high address - * (>PAGE_OFFSET), but is considered to be part of the user - * address space. + * Faults in the vsyscall page might need emulation. The + * vsyscall page is at a high address (>PAGE_OFFSET), but is + * considered to be part of the user address space. * * The vsyscall page does not have a "real" VMA, so do this * emulation before we go searching for VMAs. */ - if ((hw_error_code & X86_PF_INSTR) && is_vsyscall_vaddr(address)) { - if (emulate_vsyscall(regs, address)) + if (is_vsyscall_vaddr(address)) { + if (emulate_vsyscall(hw_error_code, regs, address)) return; } #endif |