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| author | Dan Carpenter <dan.carpenter@linaro.org> | 2024-08-01 17:44:03 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2024-08-07 12:44:16 +0200 |
| commit | 4ae0c2b91110dab6f4291c2c7f99dde60ecc97d8 (patch) | |
| tree | a8faf312f679f314849f98cc786fb9da75337773 /kernel/sched/debug.c | |
| parent | sched/fair: Make balance_fair() test sched_fair_runnable() instead of rq->nr_... (diff) | |
| download | linux-4ae0c2b91110dab6f4291c2c7f99dde60ecc97d8.tar.xz linux-4ae0c2b91110dab6f4291c2c7f99dde60ecc97d8.zip | |
sched/debug: Fix fair_server_period_max value
This code has an integer overflow or sign extension bug which was caught
by gcc-13:
kernel/sched/debug.c:341:57: error: integer overflow in expression of
type 'long int' results in '-100663296' [-Werror=overflow]
341 | static unsigned long fair_server_period_max = (1 << 22) * NSEC_PER_USEC; /* ~4 seconds */
The result is that "fair_server_period_max" is set to 0xfffffffffa000000
(585 years) instead of instead of 0xfa000000 (4 seconds) that was
intended.
Fix this by changing the type to shift from (1 << 22) to (1UL << 22).
Closes: https://lore.kernel.org/all/CA+G9fYtE2GAbeqU+AOCffgo2oH0RTJUxU+=Pi3cFn4di_KgBAQ@mail.gmail.com/
Fixes: d741f297bcea ("sched/fair: Fair server interface")
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Reported-by: Arnd Bergmann <arnd@kernel.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/a936b991-e464-4bdf-94ab-08e25d364986@stanley.mountain
Diffstat (limited to 'kernel/sched/debug.c')
| -rw-r--r-- | kernel/sched/debug.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index e75914e7d2a8..831a77ab8466 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -338,7 +338,7 @@ enum dl_param { DL_PERIOD, }; -static unsigned long fair_server_period_max = (1 << 22) * NSEC_PER_USEC; /* ~4 seconds */ +static unsigned long fair_server_period_max = (1UL << 22) * NSEC_PER_USEC; /* ~4 seconds */ static unsigned long fair_server_period_min = (100) * NSEC_PER_USEC; /* 100 us */ static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubuf, |