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| author |   Jann Horn <jannh@google.com> | 2018-08-28 22:14:18 +0200 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2018-09-03 15:12:09 +0200 |
| commit | 75045f77f7a73e617494d7a1fcf4e9c1849cec39 (patch) | |
| tree | 9d6a2482457cdf964c7882b86961ad83dde4f095 /arch/x86/lib/csum-copy_64.S | |
| parent | x86/kprobes: Stop calling fixup_exception() from kprobe_fault_handler() (diff) | |
| download | wireguard-linux-75045f77f7a73e617494d7a1fcf4e9c1849cec39.tar.xz wireguard-linux-75045f77f7a73e617494d7a1fcf4e9c1849cec39.zip | |
x86/extable: Introduce _ASM_EXTABLE_UA for uaccess fixups
Currently, most fixups for attempting to access userspace memory are
handled using _ASM_EXTABLE, which is also used for various other types of
fixups (e.g. safe MSR access, IRET failures, and a bunch of other things).
In order to make it possible to add special safety checks to uaccess fixups
(in particular, checking whether the fault address is actually in
userspace), introduce a new exception table handler ex_handler_uaccess()
and wire it up to all the user access fixups (excluding ones that
already use _ASM_EXTABLE_EX).
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: kernel-hardening@lists.openwall.com
Cc: dvyukov@google.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20180828201421.157735-5-jannh@google.com
Diffstat (limited to 'arch/x86/lib/csum-copy_64.S')
| -rw-r--r-- | arch/x86/lib/csum-copy_64.S | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/lib/csum-copy_64.S b/arch/x86/lib/csum-copy_64.S index 45a53dfe1859..a4a379e79259 100644 --- a/arch/x86/lib/csum-copy_64.S +++ b/arch/x86/lib/csum-copy_64.S @@ -31,14 +31,18 @@ .macro source 10: - _ASM_EXTABLE(10b, .Lbad_source) + _ASM_EXTABLE_UA(10b, .Lbad_source) .endm .macro dest 20: - _ASM_EXTABLE(20b, .Lbad_dest) + _ASM_EXTABLE_UA(20b, .Lbad_dest) .endm + /* + * No _ASM_EXTABLE_UA; this is used for intentional prefetch on a + * potentially unmapped kernel address. + */ .macro ignore L=.Lignore 30: _ASM_EXTABLE(30b, \L) |