Commit 75c5d6b1 authored by Rohan McLure's avatar Rohan McLure Committed by Michael Ellerman
Browse files

powerpc/64: Sanitise common exit code for interrupts 



Interrupt code is shared between Book3E/S 64-bit systems for interrupt
handlers. Ensure that exit code correctly restores non-volatile gprs on
each system when CONFIG_INTERRUPT_SANITIZE_REGISTERS is enabled.

Also introduce macros for clearing/restoring registers on interrupt
entry for when this configuration option is either disabled or enabled.

Reviewed-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarRohan McLure <rmclure@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221201071019.1953023-3-rmclure@linux.ibm.com
parent cbf892ba

arch/powerpc/kernel/interrupt_64.S

+6 −0
Original line number Diff line number Diff line
@@ -408,9 +408,11 @@ interrupt_return_\srr\()_user: /* make backtraces match the _kernel variant */ 
_ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\()_user)

	addi	r3,r1,STACK_INT_FRAME_REGS

	bl	interrupt_exit_user_prepare

#ifndef CONFIG_INTERRUPT_SANITIZE_REGISTERS

	cmpdi	r3,0

	bne-	.Lrestore_nvgprs_\srr

.Lrestore_nvgprs_\srr\()_cont:

#endif

	std	r1,PACA_EXIT_SAVE_R1(r13) /* save r1 for restart */

#ifdef CONFIG_PPC_BOOK3S

.Linterrupt_return_\srr\()_user_rst_start:
@@ -424,6 +426,7 @@ _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\()_user) 
	stb	r11,PACAIRQHAPPENED(r13) # clear out possible HARD_DIS



.Lfast_user_interrupt_return_\srr\():

	SANITIZE_RESTORE_NVGPRS()

#ifdef CONFIG_PPC_BOOK3S

	.ifc \srr,srr

	lbz	r4,PACASRR_VALID(r13)
@@ -493,9 +496,11 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) 
	b	.	/* prevent speculative execution */

.Linterrupt_return_\srr\()_user_rst_end:



#ifndef CONFIG_INTERRUPT_SANITIZE_REGISTERS

.Lrestore_nvgprs_\srr\():

	REST_NVGPRS(r1)

	b	.Lrestore_nvgprs_\srr\()_cont

#endif



#ifdef CONFIG_PPC_BOOK3S

interrupt_return_\srr\()_user_restart:
@@ -585,6 +590,7 @@ _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\()_kernel) 
	stb	r11,PACAIRQHAPPENED(r13) // clear the possible HARD_DIS



.Lfast_kernel_interrupt_return_\srr\():

	SANITIZE_RESTORE_NVGPRS()

	cmpdi	cr1,r3,0

#ifdef CONFIG_PPC_BOOK3S

	.ifc \srr,srr