Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 71999d98 authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge Committed by Ingo Molnar
Browse files

x86/paravirt: Use normal calling sequences for irq enable/disable 



Bastian Blank reported a boot crash with stackprotector enabled,
and debugged it back to edx register corruption.

For historical reasons irq enable/disable/save/restore had special
calling sequences to make them more efficient.  With the more
recent introduction of higher-level and more general optimisations
this is no longer necessary so we can just use the normal PVOP_
macros.

This fixes some residual bugs in the old implementations which left
edx liable to inadvertent clobbering. Also, fix some bugs in
__PVOP_VCALLEESAVE which were revealed by actual use.

Reported-by: default avatarBastian Blank <bastian@waldi.eu.org>
Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Cc: Xen-devel <xen-devel@lists.xensource.com>
LKML-Reference: <4AD3BC9B.7040501@goop.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent d1705c55

arch/x86/include/asm/paravirt.h

+4 −24
Original line number Diff line number Diff line
@@ -840,42 +840,22 @@ static __always_inline void __raw_spin_unlock(struct raw_spinlock *lock) 


static inline unsigned long __raw_local_save_flags(void)

{

	unsigned long f;



	asm volatile(paravirt_alt(PARAVIRT_CALL)

		     : "=a"(f)

		     : paravirt_type(pv_irq_ops.save_fl),

		       paravirt_clobber(CLBR_EAX)

		     : "memory", "cc");

	return f;

	return PVOP_CALLEE0(unsigned long, pv_irq_ops.save_fl);

}



static inline void raw_local_irq_restore(unsigned long f)

{

	asm volatile(paravirt_alt(PARAVIRT_CALL)

		     : "=a"(f)

		     : PV_FLAGS_ARG(f),

		       paravirt_type(pv_irq_ops.restore_fl),

		       paravirt_clobber(CLBR_EAX)

		     : "memory", "cc");

	PVOP_VCALLEE1(pv_irq_ops.restore_fl, f);

}



static inline void raw_local_irq_disable(void)

{

	asm volatile(paravirt_alt(PARAVIRT_CALL)

		     :

		     : paravirt_type(pv_irq_ops.irq_disable),

		       paravirt_clobber(CLBR_EAX)

		     : "memory", "eax", "cc");

	PVOP_VCALLEE0(pv_irq_ops.irq_disable);

}



static inline void raw_local_irq_enable(void)

{

	asm volatile(paravirt_alt(PARAVIRT_CALL)

		     :

		     : paravirt_type(pv_irq_ops.irq_enable),

		       paravirt_clobber(CLBR_EAX)

		     : "memory", "eax", "cc");

	PVOP_VCALLEE0(pv_irq_ops.irq_enable);

}



static inline unsigned long __raw_local_irq_save(void)

arch/x86/include/asm/paravirt_types.h

+6 −4
Original line number Diff line number Diff line
@@ -494,10 +494,11 @@ int paravirt_disable_iospace(void); 
#define EXTRA_CLOBBERS

#define VEXTRA_CLOBBERS

#else  /* CONFIG_X86_64 */

/* [re]ax isn't an arg, but the return val */

#define PVOP_VCALL_ARGS					\

	unsigned long __edi = __edi, __esi = __esi,	\

		__edx = __edx, __ecx = __ecx

#define PVOP_CALL_ARGS		PVOP_VCALL_ARGS, __eax

		__edx = __edx, __ecx = __ecx, __eax = __eax

#define PVOP_CALL_ARGS		PVOP_VCALL_ARGS



#define PVOP_CALL_ARG1(x)		"D" ((unsigned long)(x))

#define PVOP_CALL_ARG2(x)		"S" ((unsigned long)(x))
@@ -509,6 +510,7 @@ int paravirt_disable_iospace(void); 
				"=c" (__ecx)

#define PVOP_CALL_CLOBBERS	PVOP_VCALL_CLOBBERS, "=a" (__eax)



/* void functions are still allowed [re]ax for scratch */

#define PVOP_VCALLEE_CLOBBERS	"=a" (__eax)

#define PVOP_CALLEE_CLOBBERS	PVOP_VCALLEE_CLOBBERS
@@ -583,8 +585,8 @@ int paravirt_disable_iospace(void); 
		       VEXTRA_CLOBBERS,					\

		       pre, post, ##__VA_ARGS__)



#define __PVOP_VCALLEESAVE(rettype, op, pre, post, ...)			\

	____PVOP_CALL(rettype, op.func, CLBR_RET_REG,			\

#define __PVOP_VCALLEESAVE(op, pre, post, ...)				\

	____PVOP_VCALL(op.func, CLBR_RET_REG,				\

		      PVOP_VCALLEE_CLOBBERS, ,				\

		      pre, post, ##__VA_ARGS__)