Messages in this thread Patch in this message |  | | | Date | Fri, 20 Oct 2006 17:15:44 +0400 | | From | Alexey Dobriyan <> | | Subject | [PATCH 3/3] Enforce "unsigned long flags;" when spinlocking |
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Make it break or warn if you pass to spin_lock_irqsave() and friends something different from "unsigned long flags;". Suprisingly large amount of these was caught by recent commit c53421b18f205c5f97c604ae55c6a921f034b0f6 .
Idea is largely from FRV typechecking.
Note #1: checking with sparse is still needed, because a driver can save and pass around flags or something. So far patch is very intrusive. Note #2: techically, we should break only if sizeof(flags) < sizeof(unsigned long), but hey, there is opportunity to escalate. Thus != Note #3: yes, would break every single buggy out-of-tree module.
Signed-off-by: Alexey "altruistic today" Dobriyan <adobriyan@gmail.com> --- include/linux/irqflags.h | 11 ++++++- include/linux/spinlock.h | 68 ++++++++++++++++++++++++++++++++++++++--------- 2 files changed, 65 insertions(+), 14 deletions(-) --- a/include/linux/irqflags.h +++ b/include/linux/irqflags.h @@ -49,11 +49,18 @@ #define local_irq_enable() \ do { trace_hardirqs_on(); raw_local_irq_enable(); } while (0) #define local_irq_disable() \ do { raw_local_irq_disable(); trace_hardirqs_off(); } while (0) -#define local_irq_save(flags) \ - do { raw_local_irq_save(flags); trace_hardirqs_off(); } while (0) +#define local_irq_save(flags) \ + do { \ + BUILD_BUG_ON(sizeof(flags) != sizeof(unsigned long)); \ + typecheck(unsigned long, flags); \ + raw_local_irq_save(flags); \ + trace_hardirqs_off(); \ + } while (0) #define local_irq_restore(flags) \ do { \ + BUILD_BUG_ON(sizeof(flags) != sizeof(unsigned long)); \ + typecheck(unsigned long, flags); \ if (raw_irqs_disabled_flags(flags)) { \ raw_local_irq_restore(flags); \ trace_hardirqs_off(); \ --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -183,13 +183,43 @@ #define write_lock(lock) _write_lock(lo #define read_lock(lock) _read_lock(lock) #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) -#define spin_lock_irqsave(lock, flags) flags = _spin_lock_irqsave(lock) -#define read_lock_irqsave(lock, flags) flags = _read_lock_irqsave(lock) -#define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock) +#define spin_lock_irqsave(lock, flags) \ + do { \ + BUILD_BUG_ON(sizeof(flags) != sizeof(unsigned long)); \ + typecheck(unsigned long, flags); \ + flags = _spin_lock_irqsave(lock); \ + } while (0); +#define read_lock_irqsave(lock, flags) \ + do { \ + BUILD_BUG_ON(sizeof(flags) != sizeof(unsigned long)); \ + typecheck(unsigned long, flags); \ + flags = _read_lock_irqsave(lock); \ + } while (0) +#define write_lock_irqsave(lock, flags) \ + do { \ + BUILD_BUG_ON(sizeof(flags) != sizeof(unsigned long)); \ + typecheck(unsigned long, flags); \ + flags = _write_lock_irqsave(lock); \ + } while (0) #else -#define spin_lock_irqsave(lock, flags) _spin_lock_irqsave(lock, flags) -#define read_lock_irqsave(lock, flags) _read_lock_irqsave(lock, flags) -#define write_lock_irqsave(lock, flags) _write_lock_irqsave(lock, flags) +#define spin_lock_irqsave(lock, flags) \ + do { \ + BUILD_BUG_ON(sizeof(flags) != sizeof(unsigned long)); \ + typecheck(unsigned long, flags); \ + _spin_lock_irqsave(lock, flags); \ + } while (0) +#define read_lock_irqsave(lock, flags) \ + do { \ + BUILD_BUG_ON(sizeof(flags) != sizeof(unsigned long)); \ + typecheck(unsigned long, flags); \ + _read_lock_irqsave(lock, flags); \ + } while (0) +#define write_lock_irqsave(lock, flags) \ + do { \ + BUILD_BUG_ON(sizeof(flags) != sizeof(unsigned long)); \ + typecheck(unsigned long, flags); \ + _write_lock_irqsave(lock, flags); \ + } while (0) #endif #define spin_lock_irq(lock) _spin_lock_irq(lock) @@ -224,22 +254,36 @@ # define write_unlock_irq(lock) \ do { __raw_write_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0) #endif -#define spin_unlock_irqrestore(lock, flags) \ - _spin_unlock_irqrestore(lock, flags) +#define spin_unlock_irqrestore(lock, flags) \ + do { \ + BUILD_BUG_ON(sizeof(flags) != sizeof(unsigned long)); \ + typecheck(unsigned long, flags); \ + _spin_unlock_irqrestore(lock, flags); \ + } while (0) #define spin_unlock_bh(lock) _spin_unlock_bh(lock) -#define read_unlock_irqrestore(lock, flags) \ - _read_unlock_irqrestore(lock, flags) +#define read_unlock_irqrestore(lock, flags) \ + do { \ + BUILD_BUG_ON(sizeof(flags) != sizeof(unsigned long)); \ + typecheck(unsigned long, flags); \ + _read_unlock_irqrestore(lock, flags); \ + } while (0) #define read_unlock_bh(lock) _read_unlock_bh(lock) -#define write_unlock_irqrestore(lock, flags) \ - _write_unlock_irqrestore(lock, flags) +#define write_unlock_irqrestore(lock, flags) \ + do { \ + BUILD_BUG_ON(sizeof(flags) != sizeof(unsigned long)); \ + typecheck(unsigned long, flags); \ + _write_unlock_irqrestore(lock, flags); \ + } while (0) #define write_unlock_bh(lock) _write_unlock_bh(lock) #define spin_trylock_bh(lock) __cond_lock(lock, _spin_trylock_bh(lock)) #define spin_trylock_irq(lock) \ ({ \ + BUILD_BUG_ON(sizeof(flags) != sizeof(unsigned long)); \ + typecheck(unsigned long, flags); \ local_irq_disable(); \ spin_trylock(lock) ? \ 1 : ({ local_irq_enable(); 0; }); \ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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