Hi,
Two fixes for x86 arch.
## Changelog v3: - Fold in changes from Alviro, the previous version is still leaking @bank[n].
v2: - Fix wrong copy/paste.
## Summary [PATCH v3 1/2] x86/delay: Fix the wrong asm constraint in `delay_loop()`
The asm constraint does not reflect that the asm statement can modify the value of @loops. But the asm statement in delay_loop() does change the @loops.
If by any chance the compiler inlines this function, it may clobber random stuff (e.g. local variable, important temporary value in reg, etc.).
Fortunately, delay_loop() is only called indirectly (so it can't inline), and then the register it clobbers is %rax (which is by the nature of the calling convention, it's a caller saved register), so it didn't yield any bug.
^ That shouldn't be an excuse for using the wrong constraint anyway.
This changes "a" (as an input) to "+a" (as an input and output).
[PATCH v3 2/2] x86/mce/amd: Fix memory leak when `threshold_create_bank()` fails.
@bp is a local variable, calling mce_threshold_remove_device() when threshold_create_bank() fails will not free the @bp. Note that mce_threshold_remove_device() frees the @bp only if it's already stored in the @threshold_banks per-CPU variable.
At that point, the @threshold_banks per-CPU variable is still NULL, so the mce_threshold_remove_device() will just be a no-op and the @bp is leaked.
Fix this by storing @bp to @threshold_banks before the loop, so in case we fail, mce_threshold_remove_device() will free the @bp.
This bug is introduced by commit 6458de97fc15530b544 ("x86/mce/amd: Straighten CPU hotplug path") [1].
Cc: Borislav Petkov bp@alien8.de Cc: Dave Hansen dave.hansen@linux.intel.com Cc: "H. Peter Anvin" hpa@zytor.com Cc: Ingo Molnar mingo@redhat.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Tony Luck tony.luck@intel.com Signed-off-by: Alviro Iskandar Setiawan alviro.iskandar@gnuweeb.org Signed-off-by: Ammar Faizi ammarfaizi2@gnuweeb.org --- Ammar Faizi (2): x86/delay: Fix the wrong asm constraint in `delay_loop()` x86/mce/amd: Fix memory leak when `threshold_create_bank()` fails
arch/x86/kernel/cpu/mce/amd.c | 16 ++++++++++------ arch/x86/lib/delay.c | 4 ++-- 2 files changed, 12 insertions(+), 8 deletions(-)
base-commit: 7e57714cd0ad2d5bb90e50b5096a0e671dec1ef3