The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=0a02a47fd94a8326e84ac0a6cb857342b59671f8
commit 0a02a47fd94a8326e84ac0a6cb857342b59671f8 Author: Konstantin Belousov <[email protected]> AuthorDate: 2026-05-27 08:21:10 +0000 Commit: Konstantin Belousov <[email protected]> CommitDate: 2026-05-28 17:26:56 +0000 x86: for wrmsr_early_safe(), catch all exceptions, not only #GP Reviewed by: olce Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D57264 --- sys/amd64/amd64/machdep.c | 24 +++++++++++++++--------- sys/amd64/amd64/support.S | 7 +++---- 2 files changed, 18 insertions(+), 13 deletions(-) diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c index db2fd5927f7f..8df4868f5312 100644 --- a/sys/amd64/amd64/machdep.c +++ b/sys/amd64/amd64/machdep.c @@ -1827,29 +1827,35 @@ wrmsr_early_safe_start(void) { struct region_descriptor efi_idt; struct gate_descriptor *gpf_descr; + int i; sidt(&wrmsr_early_safe_orig_efi_idt); efi_idt.rd_limit = 32 * sizeof(idt0[0]); efi_idt.rd_base = (uintptr_t)idt0; lidt(&efi_idt); - gpf_descr = &idt0[IDT_GP]; - gpf_descr->gd_looffset = (uintptr_t)wrmsr_early_safe_gp_handler; - gpf_descr->gd_hioffset = (uintptr_t)wrmsr_early_safe_gp_handler >> 16; - gpf_descr->gd_selector = rcs(); - gpf_descr->gd_type = SDT_SYSTGT; - gpf_descr->gd_p = 1; + /* Setup handler for all possible exceptions. */ + for (i = 0; i < 32; i++) { + gpf_descr = &idt0[i]; + gpf_descr->gd_looffset = + (uintptr_t)wrmsr_early_safe_gp_handler; + gpf_descr->gd_hioffset = + (uintptr_t)wrmsr_early_safe_gp_handler >> 16; + gpf_descr->gd_selector = rcs(); + gpf_descr->gd_type = SDT_SYSTGT; + gpf_descr->gd_p = 1; + } } void wrmsr_early_safe_end(void) { - struct gate_descriptor *gpf_descr; + int i; lidt(&wrmsr_early_safe_orig_efi_idt); - gpf_descr = &idt0[IDT_GP]; - memset_early(gpf_descr, 0, sizeof(*gpf_descr)); + for (i = 0; i < 32; i++) + memset_early(&idt0[i], 0, sizeof(idt0[0])); } int diff --git a/sys/amd64/amd64/support.S b/sys/amd64/amd64/support.S index 09d4ef85b087..1d7d05843ba8 100644 --- a/sys/amd64/amd64/support.S +++ b/sys/amd64/amd64/support.S @@ -1566,20 +1566,19 @@ msr_onfault: ret ENTRY(wrmsr_early_safe) + movq %rsp,%r11 movl %edi,%ecx movl %esi,%eax sarq $32,%rsi movl %esi,%edx wrmsr xorl %eax,%eax -wrmsr_early_faulted: ret ENTRY(wrmsr_early_safe_gp_handler) - addq $8,%rsp + movq %r11,%rsp movl $EFAULT,%eax - movq $wrmsr_early_faulted,(%rsp) - iretq + ret /* * void pmap_pti_pcid_invalidate(uint64_t ucr3, uint64_t kcr3);
