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Date:      Sun, 12 Apr 2026 13:44:30 +0000
From:      Kyle Evans <kevans@FreeBSD.org>
To:        src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org
Cc:        Kristofer Peterson <kris@tranception.com>
Subject:   git: 9d87f30b3322 - stable/14 - kern/amd64/machdep: Replace memset in wrmsr_early_safe_end
Message-ID:  <69dba1be.43295.2bd88560@gitrepo.freebsd.org>
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The branch stable/14 has been updated by kevans:

URL: https://cgit.FreeBSD.org/src/commit/?id=9d87f30b3322c910a2cb68442e5d35daea59df82

commit 9d87f30b3322c910a2cb68442e5d35daea59df82
Author:     Kristofer Peterson <kris@tranception.com>
AuthorDate: 2026-03-09 19:40:34 +0000
Commit:     Kyle Evans <kevans@FreeBSD.org>
CommitDate: 2026-04-12 13:43:46 +0000

    kern/amd64/machdep: Replace memset in wrmsr_early_safe_end
    
    GENERIC-KASAN kernel failed to boot on a Dell PowerEdge C6615 with
    an AMD EPYC 8224P CPU; UEFI BIOS caught a #GP exception with %RIP
    in kasan_memset where %GS relative pointer (curthread->td_pflags2)
    was dereferenced. Investigation led to wrmsr_early_safe_end which
    calls memset to clear early #GP IDT entry. Replacing memset with
    __builtin_memset_inline still resulted in the compiler emitting a
    call to the memset resolver in GENERIC-KASAN build and the kernel
    stil faulted during boot. This version which has been successfully
    tested with both GENERIC and GENERIC-KASAN kernels uses memset_early.
    
    Signed-off-by: Kristofer Peterson <kris@tranception.com>
    Reviewed-by: kib
    (cherry picked from commit 615f1b9eb17c921bbcb0cce2b9ad61910361325b)
---
 sys/amd64/amd64/machdep.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index f5733eef685e..e4761a2e8579 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -1863,7 +1863,7 @@ wrmsr_early_safe_end(void)
 	lidt(&wrmsr_early_safe_orig_efi_idt);
 
 	gpf_descr = &idt0[IDT_GP];
-	memset(gpf_descr, 0, sizeof(*gpf_descr));
+	memset_early(gpf_descr, 0, sizeof(*gpf_descr));
 }
 
 #ifdef KDB
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