iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

selftests/powerpc: Fix pkey access right updates

Browse Source 
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: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200604125610.649668-2-sandipan@linux.ibm.com
This commit is contained in:
Sandipan Das 2020-06-04 18:26:08 +05:30 committed by Michael Ellerman
parent 105fb38124
commit 828ca4320d
3 changed files with 8 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
tools/testing/selftests/powerpc/include/reg.h
View File

@ -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

2
tools/testing/selftests/powerpc/ptrace/core-pkey.c
View File

@ -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

2
tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
View File

@ -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);