Commit 16db5436 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/32: Save remaining registers in exception prolog 



Save non volatile registers, XER, CTR, MSR and NIP in exception prolog.

Also assign proper value to r2 and r3 there.

For now, recalculate thread pointer in prepare_transfer_to_handler.
It will disappear once KUAP is ported to C.

And remove the comment which is now completely wrong.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/56f0cde9dd0362edf2ddba4d887552013eee7329.1615552867.git.christophe.leroy@csgroup.eu
parent a3055978

arch/powerpc/kernel/entry_32.S

+4 −23
Original line number Diff line number Diff line
@@ -48,29 +48,11 @@ 
 */

	.align	12



/*

 * This code finishes saving the registers to the exception frame

 * and jumps to the appropriate handler for the exception, turning

 * on address translation.

 * Note that we rely on the caller having set cr0.eq iff the exception

 * occurred in kernel mode (i.e. MSR:PR = 0).

 */

	.globl	prepare_transfer_to_handler

prepare_transfer_to_handler:

	SAVE_NVGPRS(r11)

	addi	r3,r1,STACK_FRAME_OVERHEAD

	stw	r2,GPR2(r11)

	stw	r12,_NIP(r11)

	stw	r9,_MSR(r11)

	andi.	r2,r9,MSR_PR

	mfctr	r12

	mfspr	r2,SPRN_XER

	stw	r12,_CTR(r11)

	stw	r2,_XER(r11)

	mfspr	r12,SPRN_SPRG_THREAD

	tovirt(r12, r12)

	andi.	r12,r9,MSR_PR

	addi	r12,r2,THREAD

	beq	2f

	addi	r2, r12, -THREAD

#ifdef CONFIG_PPC_BOOK3S_32

	kuep_lock r11, r12

#endif
@@ -78,8 +60,7 @@ prepare_transfer_to_handler: 


	/* if from kernel, check interrupted DOZE/NAP mode */

2:

	kuap_save_and_lock r11, r12, r9, r2, r6

	addi	r2, r12, -THREAD

	kuap_save_and_lock r11, r12, r9, r5, r6

#if defined(CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)

	lwz	r12,TI_LOCAL_FLAGS(r2)

	mtcrf	0x01,r12
@@ -293,7 +274,7 @@ fast_exception_return: 


2:	REST_4GPRS(3, r11)

	lwz	r10,_CCR(r11)

	REST_GPR(1, r11)

	REST_2GPRS(1, r11)

	mtcr	r10

	lwz	r10,_LINK(r11)

	mtlr	r10

arch/powerpc/kernel/head_32.h

+12 −0
Original line number Diff line number Diff line
@@ -117,6 +117,18 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt) 
	stw	r10,_TRAP(r1)

	SAVE_4GPRS(3, r1)

	SAVE_2GPRS(7, r1)

	SAVE_NVGPRS(r1)

	stw	r2,GPR2(r1)

	stw	r12,_NIP(r1)

	stw	r9,_MSR(r1)

	mfctr	r10

	mfspr	r2,SPRN_SPRG_THREAD

	stw	r10,_CTR(r1)

	tovirt(r2, r2)

	mfspr	r10,SPRN_XER

	addi	r2, r2, -THREAD

	stw	r10,_XER(r1)

	addi	r3,r1,STACK_FRAME_OVERHEAD

.endm



.macro prepare_transfer_to_handler

arch/powerpc/kernel/head_booke.h

+12 −0
Original line number Diff line number Diff line
@@ -89,6 +89,18 @@ END_BTB_FLUSH_SECTION 
	stw	r10,_TRAP(r1)

	SAVE_4GPRS(3, r1)

	SAVE_2GPRS(7, r1)

	SAVE_NVGPRS(r1)

	stw	r2,GPR2(r1)

	stw	r12,_NIP(r1)

	stw	r9,_MSR(r1)

	mfctr	r10

	mfspr	r2,SPRN_SPRG_THREAD

	stw	r10,_CTR(r1)

	tovirt(r2, r2)

	mfspr	r10,SPRN_XER

	addi	r2, r2, -THREAD

	stw	r10,_XER(r1)

	addi	r3,r1,STACK_FRAME_OVERHEAD

.endm



.macro prepare_transfer_to_handler