leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

x86/mce/amd: Protect a not-fully initialized bank from the thresholding interrupt

Browse Source 
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
This commit is contained in:
Thomas Gleixner 2020-03-12 20:05:43 +01:00 committed by Borislav Petkov
parent c9bf318f77
commit cca9cc05fe
1 changed files with 17 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
arch/x86/kernel/cpu/mce/amd.c
View File

@ -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