diff options
| author | Colin Ian King <colin.king@canonical.com> | 2019-06-19 19:14:46 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-06-22 11:59:31 +0200 |
| commit | ea136a112d89bade596314a1ae49f748902f4727 (patch) | |
| tree | aaf91cd28e72da9cbaaf5bef2f9cf28e5ee72b56 | |
| parent | 32f010deab575199df4ebe7b6aec20c17bb7eccd (diff) | |
x86/apic: Fix integer overflow on 10 bit left shift of cpu_khz
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
| -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 177aa8ef2afa..85be316665b4 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1464,7 +1464,8 @@ static void apic_pending_intr_clear(void) if (queued) { if (boot_cpu_has(X86_FEATURE_TSC) && cpu_khz) { ntsc = rdtsc(); - max_loops = (cpu_khz << 10) - (ntsc - tsc); + max_loops = (long long)cpu_khz << 10; + max_loops -= ntsc - tsc; } else { max_loops--; } |