[tip: ras/core] x86/MCE/AMD: Use an u64 for bank_map

From: tip-bot2 for Muralidhara M K
Date: Sun Mar 19 2023 - 14:20:25 EST


The following commit has been merged into the ras/core branch of tip:

Commit-ID: 4c1cdec319b9aadb65737c3eb1f5cb74bd6aa156
Gitweb: https://git.kernel.org/tip/4c1cdec319b9aadb65737c3eb1f5cb74bd6aa156
Author: Muralidhara M K <muralimk@xxxxxxx>
AuthorDate: Fri, 27 Jan 2023 15:16:01
Committer: Borislav Petkov (AMD) <bp@xxxxxxxxx>
CommitterDate: Sun, 19 Mar 2023 19:07:04 +01:00

x86/MCE/AMD: Use an u64 for bank_map

Thee maximum number of MCA banks is 64 (MAX_NR_BANKS), see

a0bc32b3cacf ("x86/mce: Increase maximum number of banks to 64").

However, the bank_map which contains a bitfield of which banks to
initialize is of type unsigned int and that overflows when those bit
numbers are >= 32, leading to UBSAN complaining correctly:

UBSAN: shift-out-of-bounds in arch/x86/kernel/cpu/mce/amd.c:1365:38
shift exponent 32 is too large for 32-bit type 'int'

Change the bank_map to a u64 and use the proper BIT_ULL() macro when
modifying bits in there.

[ bp: Rewrite commit message. ]

Fixes: a0bc32b3cacf ("x86/mce: Increase maximum number of banks to 64")
Signed-off-by: Muralidhara M K <muralimk@xxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230127151601.1068324-1-muralimk@xxxxxxx
---
arch/x86/kernel/cpu/mce/amd.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 4881893..0b971f9 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -235,10 +235,10 @@ static DEFINE_PER_CPU(struct threshold_bank **, threshold_banks);
* 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);
+static DEFINE_PER_CPU(u64, bank_map);

/* Map of banks that have more than MCA_MISC0 available. */
-static DEFINE_PER_CPU(u32, smca_misc_banks_map);
+static DEFINE_PER_CPU(u64, smca_misc_banks_map);

static void amd_threshold_interrupt(void);
static void amd_deferred_error_interrupt(void);
@@ -267,7 +267,7 @@ static void smca_set_misc_banks_map(unsigned int bank, unsigned int cpu)
return;

if (low & MASK_BLKPTR_LO)
- per_cpu(smca_misc_banks_map, cpu) |= BIT(bank);
+ per_cpu(smca_misc_banks_map, cpu) |= BIT_ULL(bank);

}

@@ -530,7 +530,7 @@ static u32 smca_get_block_address(unsigned int bank, unsigned int block,
if (!block)
return MSR_AMD64_SMCA_MCx_MISC(bank);

- if (!(per_cpu(smca_misc_banks_map, cpu) & BIT(bank)))
+ if (!(per_cpu(smca_misc_banks_map, cpu) & BIT_ULL(bank)))
return 0;

return MSR_AMD64_SMCA_MCx_MISCy(bank, block - 1);
@@ -574,7 +574,7 @@ prepare_threshold_block(unsigned int bank, unsigned int block, u32 addr,
int new;

if (!block)
- per_cpu(bank_map, cpu) |= (1 << bank);
+ per_cpu(bank_map, cpu) |= BIT_ULL(bank);

memset(&b, 0, sizeof(b));
b.cpu = cpu;
@@ -878,7 +878,7 @@ static void amd_threshold_interrupt(void)
return;

for (bank = 0; bank < this_cpu_read(mce_num_banks); ++bank) {
- if (!(per_cpu(bank_map, cpu) & (1 << bank)))
+ if (!(per_cpu(bank_map, cpu) & BIT_ULL(bank)))
continue;

first_block = bp[bank]->blocks;
@@ -1356,7 +1356,7 @@ int mce_threshold_create_device(unsigned int cpu)
return -ENOMEM;

for (bank = 0; bank < numbanks; ++bank) {
- if (!(this_cpu_read(bank_map) & (1 << bank)))
+ if (!(this_cpu_read(bank_map) & BIT_ULL(bank)))
continue;
err = threshold_create_bank(bp, cpu, bank);
if (err) {