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| author | Thomas Gleixner <tglx@linutronix.de> | 2020-03-12 20:05:43 +0100 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-04-14 15:47:55 +0200 |
| commit | cca9cc05fe98f3eb0cfb58ec6739cfc9d0b4ccbf (patch) | |
| tree | ea347516f86febe7708aefc5d922e9b49ab5101f /arch | |
| parent | x86/mce/amd: Init thresholding machinery only on relevant vendors (diff) | |
| download | linux-cca9cc05fe98f3eb0cfb58ec6739cfc9d0b4ccbf.tar.xz linux-cca9cc05fe98f3eb0cfb58ec6739cfc9d0b4ccbf.zip | |
x86/mce/amd: Protect a not-fully initialized bank from the thresholding interrupt
Make sure the thresholding bank descriptor is fully initialized when the
thresholding interrupt fires after a hotplug event.
[ bp: Write commit message and document long-forgotten bank_map. ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200403161943.1458-4-bp@alien8.de
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/cpu/mce/amd.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c index c3b3326ad4ac..563942157758 100644 --- a/arch/x86/kernel/cpu/mce/amd.c +++ b/arch/x86/kernel/cpu/mce/amd.c @@ -192,7 +192,12 @@ EXPORT_SYMBOL_GPL(smca_banks); static char buf_mcatype[MAX_MCATYPE_NAME_LEN]; static DEFINE_PER_CPU(struct threshold_bank **, threshold_banks); -static DEFINE_PER_CPU(unsigned int, bank_map); /* see which banks are on */ + +/* + * A list of the banks enabled on each logical CPU. Controls which respective + * descriptors to initialize later in mce_threshold_create_device(). + */ +static DEFINE_PER_CPU(unsigned int, bank_map); /* Map of banks that have more than MCA_MISC0 available. */ static DEFINE_PER_CPU(u32, smca_misc_banks_map); @@ -1016,13 +1021,22 @@ static void log_and_reset_block(struct threshold_block *block) static void amd_threshold_interrupt(void) { struct threshold_block *first_block = NULL, *block = NULL, *tmp = NULL; + struct threshold_bank **bp = this_cpu_read(threshold_banks); unsigned int bank, cpu = smp_processor_id(); + /* + * Validate that the threshold bank has been initialized already. The + * handler is installed at boot time, but on a hotplug event the + * interrupt might fire before the data has been initialized. + */ + if (!bp) + return; + for (bank = 0; bank < this_cpu_read(mce_num_banks); ++bank) { if (!(per_cpu(bank_map, cpu) & (1 << bank))) continue; - first_block = per_cpu(threshold_banks, cpu)[bank]->blocks; + first_block = bp[bank]->blocks; if (!first_block) continue; @@ -1247,6 +1261,7 @@ static int allocate_threshold_blocks(unsigned int cpu, struct threshold_bank *tb INIT_LIST_HEAD(&b->miscj); + /* This is safe as @tb is not visible yet */ if (tb->blocks) list_add(&b->miscj, &tb->blocks->miscj); else |