diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-05-23 17:47:19 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-05-23 17:47:19 -0700 |
commit | 5b828263b180c16037382e8ffddd0611a363aabe (patch) | |
tree | 23e3fb6375d05942074013b78e8337db303de724 /arch | |
parent | eb39e37d5cebdf0f63ee2a315fc23b035d81b4b0 (diff) | |
parent | fa619f5156cf1ee3773edc6d756be262c9ef35de (diff) |
Merge tag 'ras_core_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 RAS updates from Borislav Petkov:
- Simplification of the AMD MCE error severity grading logic along with
supplying critical panic MCEs with accompanying error messages for
more human-friendly diagnostics.
- Misc fixes
* tag 'ras_core_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Add messages for panic errors in AMD's MCE grading
x86/mce: Simplify AMD severity grading logic
x86/MCE/AMD: Fix memory leak when threshold_create_bank() fails
x86/mce: Avoid unnecessary padding in struct mce_bank
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/kernel/cpu/mce/amd.c | 32 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/mce/core.c | 4 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/mce/severity.c | 110 |
3 files changed, 67 insertions, 79 deletions
diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c index 1940d305db1c..1c87501e0fa3 100644 --- a/arch/x86/kernel/cpu/mce/amd.c +++ b/arch/x86/kernel/cpu/mce/amd.c @@ -1294,10 +1294,23 @@ out_free: kfree(bank); } +static void __threshold_remove_device(struct threshold_bank **bp) +{ + unsigned int bank, numbanks = this_cpu_read(mce_num_banks); + + for (bank = 0; bank < numbanks; bank++) { + if (!bp[bank]) + continue; + + threshold_remove_bank(bp[bank]); + bp[bank] = NULL; + } + kfree(bp); +} + int mce_threshold_remove_device(unsigned int cpu) { struct threshold_bank **bp = this_cpu_read(threshold_banks); - unsigned int bank, numbanks = this_cpu_read(mce_num_banks); if (!bp) return 0; @@ -1308,13 +1321,7 @@ int mce_threshold_remove_device(unsigned int cpu) */ this_cpu_write(threshold_banks, NULL); - for (bank = 0; bank < numbanks; bank++) { - if (bp[bank]) { - threshold_remove_bank(bp[bank]); - bp[bank] = NULL; - } - } - kfree(bp); + __threshold_remove_device(bp); return 0; } @@ -1351,15 +1358,14 @@ int mce_threshold_create_device(unsigned int cpu) if (!(this_cpu_read(bank_map) & (1 << bank))) continue; err = threshold_create_bank(bp, cpu, bank); - if (err) - goto out_err; + if (err) { + __threshold_remove_device(bp); + return err; + } } this_cpu_write(threshold_banks, bp); if (thresholding_irq_en) mce_threshold_vector = amd_threshold_interrupt; return 0; -out_err: - mce_threshold_remove_device(cpu); - return err; } diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index 981496e6bc0e..d775fcd74e98 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -69,7 +69,9 @@ DEFINE_PER_CPU_READ_MOSTLY(unsigned int, mce_num_banks); struct mce_bank { u64 ctl; /* subevents to enable */ - bool init; /* initialise bank? */ + + __u64 init : 1, /* initialise bank? */ + __reserved_1 : 63; }; static DEFINE_PER_CPU_READ_MOSTLY(struct mce_bank[MAX_NR_BANKS], mce_banks_array); diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/severity.c index 1add86935349..00483d1c27e4 100644 --- a/arch/x86/kernel/cpu/mce/severity.c +++ b/arch/x86/kernel/cpu/mce/severity.c @@ -301,85 +301,65 @@ static noinstr int error_context(struct mce *m, struct pt_regs *regs) } } -static __always_inline int mce_severity_amd_smca(struct mce *m, enum context err_ctx) +/* See AMD PPR(s) section Machine Check Error Handling. */ +static noinstr int mce_severity_amd(struct mce *m, struct pt_regs *regs, char **msg, bool is_excp) { - u64 mcx_cfg; + char *panic_msg = NULL; + int ret; /* - * We need to look at the following bits: - * - "succor" bit (data poisoning support), and - * - TCC bit (Task Context Corrupt) - * in MCi_STATUS to determine error severity. + * Default return value: Action required, the error must be handled + * immediately. */ - if (!mce_flags.succor) - 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 ((mcx_cfg & MCI_CONFIG_MCAX) && - (m->status & MCI_STATUS_TCC) && - (err_ctx == IN_KERNEL)) - return MCE_PANIC_SEVERITY; - - /* ...otherwise invoke hwpoison handler. */ - return MCE_AR_SEVERITY; -} - -/* - * See AMD Error Scope Hierarchy table in a newer BKDG. For example - * 49125_15h_Models_30h-3Fh_BKDG.pdf, section "RAS Features" - */ -static noinstr int mce_severity_amd(struct mce *m, struct pt_regs *regs, char **msg, bool is_excp) -{ - enum context ctx = error_context(m, regs); + ret = MCE_AR_SEVERITY; /* Processor Context Corrupt, no need to fumble too much, die! */ - if (m->status & MCI_STATUS_PCC) - return MCE_PANIC_SEVERITY; - - if (m->status & MCI_STATUS_UC) { - - if (ctx == IN_KERNEL) - return MCE_PANIC_SEVERITY; + if (m->status & MCI_STATUS_PCC) { + panic_msg = "Processor Context Corrupt"; + ret = MCE_PANIC_SEVERITY; + goto out; + } - /* - * On older systems where overflow_recov flag is not present, we - * should simply panic if an error overflow occurs. If - * overflow_recov flag is present and set, then software can try - * to at least kill process to prolong system operation. - */ - if (mce_flags.overflow_recov) { - if (mce_flags.smca) - return mce_severity_amd_smca(m, ctx); - - /* kill current process */ - return MCE_AR_SEVERITY; - } else { - /* at least one error was not logged */ - if (m->status & MCI_STATUS_OVER) - return MCE_PANIC_SEVERITY; - } - - /* - * For any other case, return MCE_UC_SEVERITY so that we log the - * error and exit #MC handler. - */ - return MCE_UC_SEVERITY; + if (m->status & MCI_STATUS_DEFERRED) { + ret = MCE_DEFERRED_SEVERITY; + goto out; } /* - * deferred error: poll handler catches these and adds to mce_ring so - * memory-failure can take recovery actions. + * If the UC bit is not set, the system either corrected or deferred + * the error. No action will be required after logging the error. */ - if (m->status & MCI_STATUS_DEFERRED) - return MCE_DEFERRED_SEVERITY; + if (!(m->status & MCI_STATUS_UC)) { + ret = MCE_KEEP_SEVERITY; + goto out; + } /* - * corrected error: poll handler catches these and passes responsibility - * of decoding the error to EDAC + * On MCA overflow, without the MCA overflow recovery feature the + * system will not be able to recover, panic. */ - return MCE_KEEP_SEVERITY; + if ((m->status & MCI_STATUS_OVER) && !mce_flags.overflow_recov) { + panic_msg = "Overflowed uncorrected error without MCA Overflow Recovery"; + ret = MCE_PANIC_SEVERITY; + goto out; + } + + if (!mce_flags.succor) { + panic_msg = "Uncorrected error without MCA Recovery"; + ret = MCE_PANIC_SEVERITY; + goto out; + } + + if (error_context(m, regs) == IN_KERNEL) { + panic_msg = "Uncorrected unrecoverable error in kernel context"; + ret = MCE_PANIC_SEVERITY; + } + +out: + if (msg && panic_msg) + *msg = panic_msg; + + return ret; } static noinstr int mce_severity_intel(struct mce *m, struct pt_regs *regs, char **msg, bool is_excp) |