On Fri, Mar 31, 2023 at 05:06:17AM +0100, Matthew Wilcox wrote: > On Thu, Mar 30, 2023 at 08:45:52PM -0700, Luis Chamberlain wrote: > > diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c > > index 291d4167fab8..00c9fcd90e1a 100644 > > --- a/arch/x86/kernel/cpu/intel.c > > +++ b/arch/x86/kernel/cpu/intel.c > > @@ -1177,7 +1177,7 @@ static const struct { > > static struct ratelimit_state bld_ratelimit; > > > > static unsigned int sysctl_sld_mitigate = 1; > > -static DEFINE_SEMAPHORE(buslock_sem); > > +static DEFINE_MUTEX(buslock_sem); > > > > #ifdef CONFIG_PROC_SYSCTL > > static struct ctl_table sld_sysctls[] = { > > @@ -1315,7 +1315,7 @@ static void split_lock_init(void) > > static void __split_lock_reenable_unlock(struct work_struct *work) > > { > > sld_update_msr(true); > > - up(&buslock_sem); > > + mutex_unlock(&buslock_sem); > > } > > > > static DECLARE_DELAYED_WORK(sl_reenable_unlock, __split_lock_reenable_unlock); > > ^^^ clearly unsafe. __split_lock_reenable_unlock() is called as a > delayed_work(), ie not in the context of the mutex locker. lockdep > will freak out at this. > > > @@ -351,12 +351,12 @@ virt_efi_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor, > > { > > efi_status_t status; > > > > - if (down_trylock(&efi_runtime_lock)) > > + if (!mutex_trylock(&efi_runtime_lock)) > > return EFI_NOT_READY; > > looks to me like this can be called while we're oopsing. if that's in > non-process context, lockdep will get angry. > > > @@ -149,10 +149,10 @@ EXPORT_SYMBOL_NS_GPL(efivar_lock, EFIVAR); > > */ > > int efivar_trylock(void) > > { > > - if (down_trylock(&efivars_lock)) > > + if (!mutex_trylock(&efivars_lock)) > > also can be called from oops context. > > > @@ -228,7 +228,7 @@ adb_probe_task(void *x) > > do_adb_reset_bus(); > > pr_debug("adb: finished probe task...\n"); > > > > - up(&adb_probe_mutex); > > + mutex_unlock(&adb_probe_mutex); > > adb_probe_task() can be called from a different context than the lock > holder. > > > @@ -10594,7 +10594,7 @@ static bool bnx2x_prev_is_path_marked(struct bnx2x *bp) > > struct bnx2x_prev_path_list *tmp_list; > > bool rc = false; > > > > - if (down_trylock(&bnx2x_prev_sem)) > > + if (!mutex_trylock(&bnx2x_prev_sem)) > > bet you this can be called from interrupt context. > > this really isn't something to use coccinelle for. Coccinelle gives you what *would* happen, its up to us to review if the conversion is correct. Thanks for the feedback, seems like we're not going there for some users, contrary to what we expected. Luis