Commit 828ca432 authored by Sandipan Das's avatar Sandipan Das Committed by Michael Ellerman
Browse files

selftests/powerpc: Fix pkey access right updates 



The Power ISA mandates that all writes to the Authority
Mask Register (AMR) must always be preceded as well as
succeeded by a context synchronizing instruction.

This makes sure that the tests follow this requirement
when attempting to update a pkey's access rights.

Signed-off-by: default avatarSandipan Das <sandipan@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200604125610.649668-2-sandipan@linux.ibm.com
parent 105fb381

tools/testing/selftests/powerpc/include/reg.h

+6 −0
Original line number Diff line number Diff line
@@ -57,6 +57,12 @@ 
#define SPRN_PPR       896	/* Program Priority Register */

#define SPRN_AMR       13	/* Authority Mask Register - problem state */



#define set_amr(v)	asm volatile("isync;" \

				     "mtspr " __stringify(SPRN_AMR) ",%0;" \

				     "isync" : \

				    : "r" ((unsigned long)(v)) \

				    : "memory")



/* TEXASR register bits */

#define TEXASR_FC	0xFE00000000000000

#define TEXASR_FP	0x0100000000000000

tools/testing/selftests/powerpc/ptrace/core-pkey.c

+1 −1
Original line number Diff line number Diff line
@@ -150,7 +150,7 @@ static int child(struct shared_info *info) 
	printf("%-30s AMR: %016lx pkey1: %d pkey2: %d pkey3: %d\n",

	       user_write, info->amr, pkey1, pkey2, pkey3);



	mtspr(SPRN_AMR, info->amr);

	set_amr(info->amr);



	/*

	 * We won't use pkey3. This tests whether the kernel restores the UAMOR

tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c

+1 −1
Original line number Diff line number Diff line
@@ -126,7 +126,7 @@ static int child(struct shared_info *info) 
	printf("%-30s AMR: %016lx pkey1: %d pkey2: %d pkey3: %d\n",

	       user_write, info->amr1, pkey1, pkey2, pkey3);



	mtspr(SPRN_AMR, info->amr1);

	set_amr(info->amr1);



	/* Wait for parent to read our AMR value and write a new one. */

	ret = prod_parent(&info->child_sync);