diff options
| author | Helge Deller <deller@gmx.de> | 2023-08-09 10:21:58 +0300 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2023-08-10 18:32:09 +0300 |
| commit | a0f4b7879f2e14986200747d1b545e5daac8c624 (patch) | |
| tree | 90c0f9302627476b43a470ad87cb33d24ec27c35 /arch/parisc/include | |
| parent | a027b2eca0b7e90b11a0b0ddfad0dc4068707799 (diff) | |
| download | linux-a0f4b7879f2e14986200747d1b545e5daac8c624.tar.xz | |
parisc: Fix lightweight spinlock checks to not break futexes
The lightweight spinlock checks verify that a spinlock has either value
0 (spinlock locked) and that not any other bits than in
__ARCH_SPIN_LOCK_UNLOCKED_VAL is set.
This breaks the current LWS code, which writes the address of the lock
into the lock word to unlock it, which was an optimization to save one
assembler instruction.
Fix it by making spinlock_types.h accessible for asm code, change the
LWS spinlock-unlocking code to write __ARCH_SPIN_LOCK_UNLOCKED_VAL into
the lock word, and add some missing lightweight spinlock checks to the
LWS path. Finally, make the spinlock checks dependend on DEBUG_KERNEL.
Noticed-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Tested-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # v6.4+
Fixes: 15e64ef6520e ("parisc: Add lightweight spinlock checks")
Diffstat (limited to 'arch/parisc/include')
| -rw-r--r-- | arch/parisc/include/asm/spinlock.h | 2 | ||||
| -rw-r--r-- | arch/parisc/include/asm/spinlock_types.h | 6 |
2 files changed, 6 insertions, 2 deletions
diff --git a/arch/parisc/include/asm/spinlock.h b/arch/parisc/include/asm/spinlock.h index edfcb9858bcb..0b326e52255e 100644 --- a/arch/parisc/include/asm/spinlock.h +++ b/arch/parisc/include/asm/spinlock.h @@ -7,8 +7,6 @@ #include <asm/processor.h> #include <asm/spinlock_types.h> -#define SPINLOCK_BREAK_INSN 0x0000c006 /* break 6,6 */ - static inline void arch_spin_val_check(int lock_val) { if (IS_ENABLED(CONFIG_LIGHTWEIGHT_SPINLOCK_CHECK)) diff --git a/arch/parisc/include/asm/spinlock_types.h b/arch/parisc/include/asm/spinlock_types.h index d65934079ebd..efd06a897c6a 100644 --- a/arch/parisc/include/asm/spinlock_types.h +++ b/arch/parisc/include/asm/spinlock_types.h @@ -4,6 +4,10 @@ #define __ARCH_SPIN_LOCK_UNLOCKED_VAL 0x1a46 +#define SPINLOCK_BREAK_INSN 0x0000c006 /* break 6,6 */ + +#ifndef __ASSEMBLY__ + typedef struct { #ifdef CONFIG_PA20 volatile unsigned int slock; @@ -27,6 +31,8 @@ typedef struct { volatile unsigned int counter; } arch_rwlock_t; +#endif /* __ASSEMBLY__ */ + #define __ARCH_RW_LOCK_UNLOCKED__ 0x01000000 #define __ARCH_RW_LOCK_UNLOCKED { .lock_mutex = __ARCH_SPIN_LOCK_UNLOCKED, \ .counter = __ARCH_RW_LOCK_UNLOCKED__ } |