p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

x86/mce/AMD: Read MSRs on the CPU allocating the threshold blocks 

Scalable MCA systems allow non-core MCA banks to only be accessible by
certain CPUs. The MSRs for these banks are Read-as-Zero on other CPUs.

During allocate_threshold_blocks(), get_block_address() can be scheduled
on CPUs other than the one allocating the block. This causes the MSRs to
be read on the wrong CPU and results in incorrect behavior.

Add a @cpu parameter to get_block_address() and pass this in to ensure
that the MSRs are only read on the CPU that is allocating the block.

Signed-off-by: Yazen Ghannam <Yazen.Ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1472673994-12235-2-git-send-email-Yazen.Ghannam@amd.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Yazen Ghannam 2016-09-12 09:59:31 +02:00 committed by Thomas Gleixner
parent bad744b7f2
commit cfee4f6f0b
1 changed files with 8 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
arch/x86/kernel/cpu/mcheck/mce_amd.c
View File

@ -293,7 +293,7 @@ static void deferred_error_interrupt_enable(struct cpuinfo_x86 *c)
wrmsr(MSR_CU_DEF_ERR, low, high); wrmsr(MSR_CU_DEF_ERR, low, high);
} }
static u32 get_block_address(u32 current_addr, u32 low, u32 high, static u32 get_block_address(unsigned int cpu, u32 current_addr, u32 low, u32 high,
unsigned int bank, unsigned int block) unsigned int bank, unsigned int block)
{ {
u32 addr = 0, offset = 0; u32 addr = 0, offset = 0;
@ -309,13 +309,13 @@ static u32 get_block_address(u32 current_addr, u32 low, u32 high,
*/ */
u32 low, high; u32 low, high;
if (rdmsr_safe(MSR_AMD64_SMCA_MCx_CONFIG(bank), &low, &high)) if (rdmsr_safe_on_cpu(cpu, MSR_AMD64_SMCA_MCx_CONFIG(bank), &low, &high))
return addr; return addr;
if (!(low & MCI_CONFIG_MCAX)) if (!(low & MCI_CONFIG_MCAX))
return addr; return addr;
if (!rdmsr_safe(MSR_AMD64_SMCA_MCx_MISC(bank), &low, &high) && if (!rdmsr_safe_on_cpu(cpu, MSR_AMD64_SMCA_MCx_MISC(bank), &low, &high) &&
(low & MASK_BLKPTR_LO)) (low & MASK_BLKPTR_LO))
addr = MSR_AMD64_SMCA_MCx_MISCy(bank, block - 1); addr = MSR_AMD64_SMCA_MCx_MISCy(bank, block - 1);
} }
@ -421,12 +421,12 @@ prepare_threshold_block(unsigned int bank, unsigned int block, u32 addr,
void mce_amd_feature_init(struct cpuinfo_x86 *c) void mce_amd_feature_init(struct cpuinfo_x86 *c)
{ {
u32 low = 0, high = 0, address = 0; u32 low = 0, high = 0, address = 0;
unsigned int bank, block; unsigned int bank, block, cpu = smp_processor_id();
int offset = -1; int offset = -1;
for (bank = 0; bank < mca_cfg.banks; ++bank) { for (bank = 0; bank < mca_cfg.banks; ++bank) {
for (block = 0; block < NR_BLOCKS; ++block) { for (block = 0; block < NR_BLOCKS; ++block) {
address = get_block_address(address, low, high, bank, block); address = get_block_address(cpu, address, low, high, bank, block);
if (!address) if (!address)
break; break;
@ -544,15 +544,14 @@ static void amd_deferred_error_interrupt(void)
static void amd_threshold_interrupt(void) static void amd_threshold_interrupt(void)
{ {
u32 low = 0, high = 0, address = 0; u32 low = 0, high = 0, address = 0;
int cpu = smp_processor_id(); unsigned int bank, block, cpu = smp_processor_id();
unsigned int bank, block;
/* assume first bank caused it */ /* assume first bank caused it */
for (bank = 0; bank < mca_cfg.banks; ++bank) { for (bank = 0; bank < mca_cfg.banks; ++bank) {
if (!(per_cpu(bank_map, cpu) & (1 << bank))) if (!(per_cpu(bank_map, cpu) & (1 << bank)))
continue; continue;
for (block = 0; block < NR_BLOCKS; ++block) { for (block = 0; block < NR_BLOCKS; ++block) {
address = get_block_address(address, low, high, bank, block); address = get_block_address(cpu, address, low, high, bank, block);
if (!address) if (!address)
break; break;
@ -774,7 +773,7 @@ static int allocate_threshold_blocks(unsigned int cpu, unsigned int bank,
if (err) if (err)
goto out_free; goto out_free;
recurse: recurse:
address = get_block_address(address, low, high, bank, ++block); address = get_block_address(cpu, address, low, high, bank, ++block);
if (!address) if (!address)
return 0; return 0;