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| author |   Borislav Petkov <bp@suse.de> | 2018-05-17 10:46:26 +0200 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2018-05-19 15:19:30 +0200 |
| commit | 78ce241099bb363b19dbd0245442e66c8de8f567 (patch) | |
| tree | 735340ca194fc1472f9671f4012fae06b3ce93f5 /arch/x86/kernel | |
| parent | Merge branch 'akpm' (patches from Andrew) (diff) | |
| download | linux-dev-78ce241099bb363b19dbd0245442e66c8de8f567.tar.xz linux-dev-78ce241099bb363b19dbd0245442e66c8de8f567.zip | |
x86/MCE/AMD: Cache SMCA MISC block addresses
... into a global, two-dimensional array and service subsequent reads from
that cache to avoid rdmsr_on_cpu() calls during CPU hotplug (IPIs with IRQs
disabled).
In addition, this fixes a KASAN slab-out-of-bounds read due to wrong usage
of the bank->blocks pointer.
Fixes: 27bd59502702 ("x86/mce/AMD: Get address from already initialized block")
Reported-by: Johannes Hirte <johannes.hirte@datenkhaos.de>
Tested-by: Johannes Hirte <johannes.hirte@datenkhaos.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Yazen Ghannam <yazen.ghannam@amd.com>
Link: http://lkml.kernel.org/r/20180414004230.GA2033@probook
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce_amd.c | 29 |
1 files changed, 14 insertions, 15 deletions
diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c index f7666eef4a87..c8e038800591 100644 --- a/arch/x86/kernel/cpu/mcheck/mce_amd.c +++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c @@ -94,6 +94,11 @@ static struct smca_bank_name smca_names[] = { [SMCA_SMU] = { "smu", "System Management Unit" }, }; +static u32 smca_bank_addrs[MAX_NR_BANKS][NR_BLOCKS] __ro_after_init = +{ + [0 ... MAX_NR_BANKS - 1] = { [0 ... NR_BLOCKS - 1] = -1 } +}; + const char *smca_get_name(enum smca_bank_types t) { if (t >= N_SMCA_BANK_TYPES) @@ -443,20 +448,26 @@ static u32 smca_get_block_address(unsigned int cpu, unsigned int bank, if (!block) return MSR_AMD64_SMCA_MCx_MISC(bank); + /* Check our cache first: */ + if (smca_bank_addrs[bank][block] != -1) + return smca_bank_addrs[bank][block]; + /* * For SMCA enabled processors, BLKPTR field of the first MISC register * (MCx_MISC0) indicates presence of additional MISC regs set (MISC1-4). */ if (rdmsr_safe_on_cpu(cpu, MSR_AMD64_SMCA_MCx_CONFIG(bank), &low, &high)) - return addr; + goto out; if (!(low & MCI_CONFIG_MCAX)) - return addr; + goto out; if (!rdmsr_safe_on_cpu(cpu, MSR_AMD64_SMCA_MCx_MISC(bank), &low, &high) && (low & MASK_BLKPTR_LO)) - return MSR_AMD64_SMCA_MCx_MISCy(bank, block - 1); + addr = MSR_AMD64_SMCA_MCx_MISCy(bank, block - 1); +out: + smca_bank_addrs[bank][block] = addr; return addr; } @@ -468,18 +479,6 @@ static u32 get_block_address(unsigned int cpu, u32 current_addr, u32 low, u32 hi if ((bank >= mca_cfg.banks) || (block >= NR_BLOCKS)) return addr; - /* Get address from already initialized block. */ - if (per_cpu(threshold_banks, cpu)) { - struct threshold_bank *bankp = per_cpu(threshold_banks, cpu)[bank]; - - if (bankp && bankp->blocks) { - struct threshold_block *blockp = &bankp->blocks[block]; - - if (blockp) - return blockp->address; - } - } - if (mce_flags.smca) return smca_get_block_address(cpu, bank, block); |