Patch "x86/MCE/AMD: Use an u64 for bank_map" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    x86/MCE/AMD: Use an u64 for bank_map

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     x86-mce-amd-use-an-u64-for-bank_map.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit dbef2732796c8fda641fd4442407923429df66ec
Author: Muralidhara M K <muralimk@xxxxxxx>
Date:   Fri Jan 27 15:16:01 2023 +0000

    x86/MCE/AMD: Use an u64 for bank_map
    
    [ Upstream commit 4c1cdec319b9aadb65737c3eb1f5cb74bd6aa156 ]
    
    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
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 4f9b7c1cfc36f..cd8db6b9ca2f5 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -197,10 +197,10 @@ 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);
@@ -229,7 +229,7 @@ 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);
 
 }
 
@@ -492,7 +492,7 @@ 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);
@@ -536,7 +536,7 @@ 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;
@@ -1048,7 +1048,7 @@ 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;
@@ -1525,7 +1525,7 @@ 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) {