diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kernel/cpu/mce/severity.c | 41 |
1 files changed, 27 insertions, 14 deletions
diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/severity.c index bb019a594a2c..7aa2bda93cbb 100644 --- a/arch/x86/kernel/cpu/mce/severity.c +++ b/arch/x86/kernel/cpu/mce/severity.c @@ -222,6 +222,9 @@ static bool is_copy_from_user(struct pt_regs *regs) struct insn insn; int ret; + if (!regs) + return false; + if (copy_from_kernel_nofault(insn_buf, (void *)regs->ip, MAX_INSN_SIZE)) return false; @@ -263,24 +266,36 @@ static bool is_copy_from_user(struct pt_regs *regs) * distinguish an exception taken in user from from one * taken in the kernel. */ -static int error_context(struct mce *m, struct pt_regs *regs) +static noinstr int error_context(struct mce *m, struct pt_regs *regs) { + int fixup_type; + bool copy_user; + if ((m->cs & 3) == 3) return IN_USER; + if (!mc_recoverable(m->mcgstatus)) return IN_KERNEL; - switch (ex_get_fixup_type(m->ip)) { + /* Allow instrumentation around external facilities usage. */ + instrumentation_begin(); + fixup_type = ex_get_fixup_type(m->ip); + copy_user = is_copy_from_user(regs); + instrumentation_end(); + + switch (fixup_type) { case EX_TYPE_UACCESS: case EX_TYPE_COPY: - if (!regs || !is_copy_from_user(regs)) + if (!copy_user) return IN_KERNEL; m->kflags |= MCE_IN_KERNEL_COPYIN; fallthrough; + case EX_TYPE_FAULT_MCE_SAFE: case EX_TYPE_DEFAULT_MCE_SAFE: m->kflags |= MCE_IN_KERNEL_RECOV; return IN_KERNEL_RECOV; + default: return IN_KERNEL; } @@ -288,8 +303,7 @@ static int error_context(struct mce *m, struct pt_regs *regs) static int mce_severity_amd_smca(struct mce *m, enum context err_ctx) { - u32 addr = MSR_AMD64_SMCA_MCx_CONFIG(m->bank); - u32 low, high; + u64 mcx_cfg; /* * We need to look at the following bits: @@ -300,11 +314,10 @@ static int mce_severity_amd_smca(struct mce *m, enum context err_ctx) if (!mce_flags.succor) return MCE_PANIC_SEVERITY; - if (rdmsr_safe(addr, &low, &high)) - return MCE_PANIC_SEVERITY; + mcx_cfg = mce_rdmsrl(MSR_AMD64_SMCA_MCx_CONFIG(m->bank)); /* TCC (Task context corrupt). If set and if IN_KERNEL, panic. */ - if ((low & MCI_CONFIG_MCAX) && + if ((mcx_cfg & MCI_CONFIG_MCAX) && (m->status & MCI_STATUS_TCC) && (err_ctx == IN_KERNEL)) return MCE_PANIC_SEVERITY; @@ -317,8 +330,8 @@ static int mce_severity_amd_smca(struct mce *m, enum context err_ctx) * See AMD Error Scope Hierarchy table in a newer BKDG. For example * 49125_15h_Models_30h-3Fh_BKDG.pdf, section "RAS Features" */ -static int mce_severity_amd(struct mce *m, struct pt_regs *regs, int tolerant, - char **msg, bool is_excp) +static noinstr int mce_severity_amd(struct mce *m, struct pt_regs *regs, int tolerant, + char **msg, bool is_excp) { enum context ctx = error_context(m, regs); @@ -370,8 +383,8 @@ static int mce_severity_amd(struct mce *m, struct pt_regs *regs, int tolerant, return MCE_KEEP_SEVERITY; } -static int mce_severity_intel(struct mce *m, struct pt_regs *regs, - int tolerant, char **msg, bool is_excp) +static noinstr int mce_severity_intel(struct mce *m, struct pt_regs *regs, + int tolerant, char **msg, bool is_excp) { enum exception excp = (is_excp ? EXCP_CONTEXT : NO_EXCP); enum context ctx = error_context(m, regs); @@ -407,8 +420,8 @@ static int mce_severity_intel(struct mce *m, struct pt_regs *regs, } } -int mce_severity(struct mce *m, struct pt_regs *regs, int tolerant, char **msg, - bool is_excp) +int noinstr mce_severity(struct mce *m, struct pt_regs *regs, int tolerant, char **msg, + bool is_excp) { if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD || boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) |