Commit 3864c489 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Linus Torvalds
Browse files

[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)
 [<c04051ed>] show_trace_log_lvl+0x58/0x16a
 [<c04057fa>] show_trace+0xd/0x10
 [<c0405913>] dump_stack+0x19/0x1b
 [<c043abfb>] trace_hardirqs_on+0xa2/0x11e
 [<c041463c>] apm_bios_call_simple+0xcd/0xfd
 [<c0415242>] apm+0x92/0x5b1
 [<c0402005>] kernel_thread_helper+0x5/0xb
DWARF2 unwinder stuck at kernel_thread_helper+0x5/0xb
Leftover inexact backtrace:
 [<c04057fa>] show_trace+0xd/0x10
 [<c0405913>] dump_stack+0x19/0x1b
 [<c043abfb>] trace_hardirqs_on+0xa2/0x11e
 [<c041463c>] apm_bios_call_simple+0xcd/0xfd
 [<c0415242>] apm+0x92/0x5b1
 [<c0402005>] kernel_thread_helper+0x5/0xb

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 6a15f46c

arch/i386/kernel/apm.c

+27 −10
Original line number Diff line number Diff line
@@ -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);

CRA Git | Maintained and supported by SUSTech CRA and CCSE