diff options
| author | Albert van der Linde <alinde@google.com> | 2020-10-15 20:13:50 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-16 11:11:22 -0700 |
| commit | 4d0e9df5e43dba52d38b251e3b909df8fa1110be (patch) | |
| tree | 6132ad46be683778740f7144820f465725a1b90e /lib/usercopy.c | |
| parent | 2c739ced5886cd8c8361faa79a9522ec05174ed0 (diff) | |
| download | lwn-4d0e9df5e43dba52d38b251e3b909df8fa1110be.tar.gz lwn-4d0e9df5e43dba52d38b251e3b909df8fa1110be.zip | |
lib, uaccess: add failure injection to usercopy functions
To test fault-tolerance of user memory access functions, introduce fault
injection to usercopy functions.
If a failure is expected return either -EFAULT or the total amount of
bytes that were not copied.
Signed-off-by: Albert van der Linde <alinde@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20200831171733.955393-3-alinde@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/usercopy.c')
| -rw-r--r-- | lib/usercopy.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/lib/usercopy.c b/lib/usercopy.c index b26509f112f9..7413dd300516 100644 --- a/lib/usercopy.c +++ b/lib/usercopy.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/bitops.h> +#include <linux/fault-inject-usercopy.h> #include <linux/instrumented.h> #include <linux/uaccess.h> @@ -10,7 +11,7 @@ unsigned long _copy_from_user(void *to, const void __user *from, unsigned long n { unsigned long res = n; might_fault(); - if (likely(access_ok(from, n))) { + if (!should_fail_usercopy() && likely(access_ok(from, n))) { instrument_copy_from_user(to, from, n); res = raw_copy_from_user(to, from, n); } @@ -25,6 +26,8 @@ EXPORT_SYMBOL(_copy_from_user); unsigned long _copy_to_user(void __user *to, const void *from, unsigned long n) { might_fault(); + if (should_fail_usercopy()) + return n; if (likely(access_ok(to, n))) { instrument_copy_to_user(to, from, n); n = raw_copy_to_user(to, from, n); |