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Date:      Sat, 25 Feb 2023 16:53:40 GMT
From:      Warner Losh <imp@FreeBSD.org>
To:        src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org
Subject:   git: 499171a98c88 - main - apic: prevent divide by zero in CPU frequency init
Message-ID:  <202302251653.31PGregX007688@gitrepo.freebsd.org>

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The branch main has been updated by imp:

URL: https://cgit.FreeBSD.org/src/commit/?id=499171a98c8813e4dc6e085461d5c47750efa555

commit 499171a98c8813e4dc6e085461d5c47750efa555
Author:     Mina Galić <freebsd@igalic.co>
AuthorDate: 2023-02-24 11:07:42 +0000
Commit:     Warner Losh <imp@FreeBSD.org>
CommitDate: 2023-02-25 16:47:40 +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
---
 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 609635bdad3d..22392901b731 100644
--- a/sys/x86/x86/local_apic.c
+++ b/sys/x86/x86/local_apic.c
@@ -953,7 +953,7 @@ 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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