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authorPeter Zijlstra <peterz@infradead.org>2016-11-14 18:06:19 +0100
committerIngo Molnar <mingo@kernel.org>2017-02-10 09:04:19 +0100
commitf405df5de3170c00e5c54f8b7cf4766044a032ba (patch)
tree62a9ba9a77852bf103b638a1b580919f0e58ffc4 /lib
parent0754445d71c37a7afd4f0790a9be4cf53c1b8cc4 (diff)
downloadlinux-f405df5de3170c00e5c54f8b7cf4766044a032ba.tar.bz2
refcount_t: Introduce a special purpose refcount type
Provide refcount_t, an atomic_t like primitive built just for refcounting. It provides saturation semantics such that overflow becomes impossible and thereby 'spurious' use-after-free is avoided. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.debug13
1 files changed, 13 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 5b37821632a2..8f1f0e609891 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -716,6 +716,19 @@ source "lib/Kconfig.kmemcheck"
source "lib/Kconfig.kasan"
+config DEBUG_REFCOUNT
+ bool "Verbose refcount checks"
+ help
+ Say Y here if you want reference counters (refcount_t and kref) to
+ generate WARNs on dubious usage. Without this refcount_t will still
+ be a saturating counter and avoid Use-After-Free by turning it into
+ a resource leak Denial-Of-Service.
+
+ Use of this option will increase kernel text size but will alert the
+ admin of potential abuse.
+
+ If in doubt, say "N".
+
endmenu # "Memory Debugging"
config ARCH_HAS_KCOV