diff options
| author | Colin Ian King <colin.king@canonical.com> | 2019-06-19 19:14:46 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2019-10-05 16:20:04 +0100 |
| commit | 04d3160054148ccff20b3440e6500ec6f02a7f88 (patch) | |
| tree | d57103132f8903ec7378e88c7c7dd6d04b2f5c20 /arch | |
| parent | a7b6e4f04e9d912d5b2a1785d00a327f7bc985d4 (diff) | |
x86/apic: Fix integer overflow on 10 bit left shift of cpu_khz
commit ea136a112d89bade596314a1ae49f748902f4727 upstream.
The left shift of unsigned int cpu_khz will overflow for large values of
cpu_khz, so cast it to a long long before shifting it to avoid overvlow.
For example, this can happen when cpu_khz is 4194305, i.e. ~4.2 GHz.
Addresses-Coverity: ("Unintentional integer overflow")
Fixes: 8c3ba8d04924 ("x86, apic: ack all pending irqs when crashed/on kexec")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: kernel-janitors@vger.kernel.org
Link: https://lkml.kernel.org/r/20190619181446.13635-1-colin.king@canonical.com
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/apic/apic.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 23604cda2178..fb2cce787f79 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1403,7 +1403,8 @@ void setup_local_APIC(void) if (queued) { if (cpu_has_tsc && cpu_khz) { rdtscll(ntsc); - max_loops = (cpu_khz << 10) - (ntsc - tsc); + max_loops = (long long)cpu_khz << 10; + max_loops -= ntsc - tsc; } else max_loops--; } |