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Date:      Tue, 28 Feb 2023 03:00:30 GMT
From:      Warner Losh <imp@FreeBSD.org>
To:        src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org
Subject:   git: a1c63b8e29e8 - stable/13 - apic: prevent divide by zero in CPU frequency init
Message-ID:  <202302280300.31S30UrQ098634@gitrepo.freebsd.org>

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The branch stable/13 has been updated by imp:

URL: https://cgit.FreeBSD.org/src/commit/?id=a1c63b8e29e832d9ada7c252e7e80ce8b94aeb41

commit a1c63b8e29e832d9ada7c252e7e80ce8b94aeb41
Author:     Mina Galić <freebsd@igalic.co>
AuthorDate: 2023-02-28 02:58:45 +0000
Commit:     Warner Losh <imp@FreeBSD.org>
CommitDate: 2023-02-28 02:58:45 +0000

    apic: prevent divide by zero in CPU frequency init
    
    If a CPU for some reason returns 0 as CPU frequency, we currently panic
    on the resulting divide by zero when trying to initialize the CPU(s) via
    APIC. When this happens, we'll fallback to measuring the frequency
    instead.
    
    PR: 269767
    Reviewed by: imp
    Pull Request: https://github.com/freebsd/freebsd-src/pull/664
    
    (cherry picked from commit 499171a98c8813e4dc6e085461d5c47750efa555)
---
 sys/x86/x86/local_apic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/x86/x86/local_apic.c b/sys/x86/x86/local_apic.c
index 4ab4e78f20e7..482b0ebd81bc 100644
--- a/sys/x86/x86/local_apic.c
+++ b/sys/x86/x86/local_apic.c
@@ -1027,7 +1027,7 @@ lapic_calibrate_initcount_cpuid_vm(void)
 
 	/* Record divided frequency. */
 	count_freq = freq / lapic_timer_divisor;
-	return (true);
+	return (count_freq != 0);
 }
 
 static uint64_t



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