From 3864c4894a7f4c03d69a90082a5bb0ab10e437ab Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 17 Oct 2006 00:10:26 -0700 Subject: [PATCH] [PATCH] lockdep: annotate i386 apm Lockdep doesn't like to enable interrupts when they are enabled already. BUG: warning at kernel/lockdep.c:1814/trace_hardirqs_on() (Not tainted) [] show_trace_log_lvl+0x58/0x16a [] show_trace+0xd/0x10 [] dump_stack+0x19/0x1b [] trace_hardirqs_on+0xa2/0x11e [] apm_bios_call_simple+0xcd/0xfd [] apm+0x92/0x5b1 [] kernel_thread_helper+0x5/0xb DWARF2 unwinder stuck at kernel_thread_helper+0x5/0xb Leftover inexact backtrace: [] show_trace+0xd/0x10 [] dump_stack+0x19/0x1b [] trace_hardirqs_on+0xa2/0x11e [] apm_bios_call_simple+0xcd/0xfd [] apm+0x92/0x5b1 [] kernel_thread_helper+0x5/0xb Signed-off-by: Peter Zijlstra Cc: Stephen Rothwell Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/apm.c | 37 +++++++++++++++++++++++++++---------- 1 file changed, 27 insertions(+), 10 deletions(-) diff --git a/arch/i386/kernel/apm.c b/arch/i386/kernel/apm.c index b42f2d914af3..2af65858d322 100644 --- a/arch/i386/kernel/apm.c +++ b/arch/i386/kernel/apm.c @@ -540,11 +540,30 @@ static inline void apm_restore_cpus(cpumask_t mask) * Also, we KNOW that for the non error case of apm_bios_call, there * is no useful data returned in the low order 8 bits of eax. */ -#define APM_DO_CLI \ - if (apm_info.allow_ints) \ - local_irq_enable(); \ - else \ + +static inline unsigned long __apm_irq_save(void) +{ + unsigned long flags; + local_save_flags(flags); + if (apm_info.allow_ints) { + if (irqs_disabled_flags(flags)) + local_irq_enable(); + } else + local_irq_disable(); + + return flags; +} + +#define apm_irq_save(flags) \ + do { flags = __apm_irq_save(); } while (0) + +static inline void apm_irq_restore(unsigned long flags) +{ + if (irqs_disabled_flags(flags)) local_irq_disable(); + else if (irqs_disabled()) + local_irq_enable(); +} #ifdef APM_ZERO_SEGS # define APM_DECL_SEGS \ @@ -596,12 +615,11 @@ static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in, save_desc_40 = gdt[0x40 / 8]; gdt[0x40 / 8] = bad_bios_desc; - local_save_flags(flags); - APM_DO_CLI; + apm_irq_save(flags); APM_DO_SAVE_SEGS; apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi); APM_DO_RESTORE_SEGS; - local_irq_restore(flags); + apm_irq_restore(flags); gdt[0x40 / 8] = save_desc_40; put_cpu(); apm_restore_cpus(cpus); @@ -640,12 +658,11 @@ static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax) save_desc_40 = gdt[0x40 / 8]; gdt[0x40 / 8] = bad_bios_desc; - local_save_flags(flags); - APM_DO_CLI; + apm_irq_save(flags); APM_DO_SAVE_SEGS; error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax); APM_DO_RESTORE_SEGS; - local_irq_restore(flags); + apm_irq_restore(flags); gdt[0x40 / 8] = save_desc_40; put_cpu(); apm_restore_cpus(cpus); -- GitLab