From: Marc Zyngier Date: Fri, 15 Jan 2016 17:41:09 +0000 (+0000) Subject: hrtimer: Catch illegal clockids X-Git-Tag: v4.6-rc1~152^2~16 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=9006a01829a50cfd6bbd4980910ed46e895e93d7;p=linux.git hrtimer: Catch illegal clockids It is way too easy to take any random clockid and feed it to the hrtimer subsystem. At best, it gets mapped to a monotonic base, but it would be better to just catch illegal values as early as possible. This patch does exactly that, mapping illegal clockids to an illegal base index, and panicing when we detect the illegal condition. Signed-off-by: Marc Zyngier Cc: Tomasz Nowicki Cc: Christoffer Dall Link: http://lkml.kernel.org/r/1452879670-16133-3-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner --- diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index a125f222fee2..cb0fe70f3c51 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -99,6 +99,9 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = }; static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = { + /* Make sure we catch unsupported clockids */ + [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES, + [CLOCK_REALTIME] = HRTIMER_BASE_REALTIME, [CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC, [CLOCK_MONOTONIC_RAW] = HRTIMER_BASE_MONOTONIC_RAW, @@ -108,7 +111,9 @@ static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = { static inline int hrtimer_clockid_to_base(clockid_t clock_id) { - return hrtimer_clock_to_base_table[clock_id]; + int base = hrtimer_clock_to_base_table[clock_id]; + BUG_ON(base == HRTIMER_MAX_CLOCK_BASES); + return base; } /*