diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-09-30 13:19:08 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2025-09-30 13:19:08 -0700 |
| commit | a65879b4584f98e6c1b80380f55ca8cfca82cb47 (patch) | |
| tree | 8bcc7ca0654d0b081bc6b38c9a996235e29b0378 /arch/x86/kernel/umip.c | |
| parent | d7ec0cf1cd79a74399b53453f9c48acbca7d6fce (diff) | |
| parent | 27b1fd62012dfe9d3eb8ecde344d7aa673695ecf (diff) | |
Merge tag 'x86_cpu_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpuid updates from Borislav Petkov:
- Make UMIP instruction detection more robust
- Correct and cleanup AMD CPU topology detection; document the relevant
CPUID leaves topology parsing precedence on AMD
- Add support for running the kernel as guest on FreeBSD's Bhyve
hypervisor
- Cleanups and improvements
* tag 'x86_cpu_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/umip: Fix decoding of register forms of 0F 01 (SGDT and SIDT aliases)
x86/umip: Check that the instruction opcode is at least two bytes
Documentation/x86/topology: Detail CPUID leaves used for topology enumeration
x86/cpu/topology: Define AMD64_CPUID_EXT_FEAT MSR
x86/cpu/topology: Check for X86_FEATURE_XTOPOLOGY instead of passing has_xtopology
x86/cpu/cacheinfo: Simplify cacheinfo_amd_init_llc_id() using _cpuid4_info
x86/cpu: Rename and move CPU model entry for Diamond Rapids
x86/cpu: Detect FreeBSD Bhyve hypervisor
Diffstat (limited to 'arch/x86/kernel/umip.c')
| -rw-r--r-- | arch/x86/kernel/umip.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c index 5a4b21389b1d..d432f3824f0c 100644 --- a/arch/x86/kernel/umip.c +++ b/arch/x86/kernel/umip.c @@ -156,15 +156,26 @@ static int identify_insn(struct insn *insn) if (!insn->modrm.nbytes) return -EINVAL; - /* All the instructions of interest start with 0x0f. */ - if (insn->opcode.bytes[0] != 0xf) + /* The instructions of interest have 2-byte opcodes: 0F 00 or 0F 01. */ + if (insn->opcode.nbytes < 2 || insn->opcode.bytes[0] != 0xf) return -EINVAL; if (insn->opcode.bytes[1] == 0x1) { switch (X86_MODRM_REG(insn->modrm.value)) { case 0: + /* The reg form of 0F 01 /0 encodes VMX instructions. */ + if (X86_MODRM_MOD(insn->modrm.value) == 3) + return -EINVAL; + return UMIP_INST_SGDT; case 1: + /* + * The reg form of 0F 01 /1 encodes MONITOR/MWAIT, + * STAC/CLAC, and ENCLS. + */ + if (X86_MODRM_MOD(insn->modrm.value) == 3) + return -EINVAL; + return UMIP_INST_SIDT; case 4: return UMIP_INST_SMSW; |