From f598c8cfcff24a0b3236cefc61a2ef4e909c2ac8 Mon Sep 17 00:00:00 2001
From: Ram Pai <linuxram@us.ibm.com>
Date: Thu, 18 Jan 2018 17:50:28 -0800
Subject: [PATCH 26/45] powerpc: cleanup AMR, IAMR when a key is allocated or
freed
References: FATE#322447, bsc#1078248
Patch-mainline: v4.16-rc1
Git-commit: 0685f217afe8279a754490954b8dcc02cb763a5d
Cleanup the bits corresponding to a key in the AMR, and IAMR
register, when the key is newly allocated/activated or is freed.
We dont want some residual bits cause the hardware enforce
unintended behavior when the key is activated or freed.
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/include/asm/pkeys.h | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index 79b105d1ff73..5ed52ac39bab 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -58,6 +58,8 @@ static inline bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey)
__mm_pkey_is_allocated(mm, pkey));
}
+extern void __arch_activate_pkey(int pkey);
+extern void __arch_deactivate_pkey(int pkey);
/*
* Returns a positive, 5-bit key on success, or -1 on failure.
* Relies on the mmap_sem to protect against concurrency in mm_pkey_alloc() and
@@ -85,6 +87,12 @@ static inline int mm_pkey_alloc(struct mm_struct *mm)
ret = ffz((u32)mm_pkey_allocation_map(mm));
__mm_pkey_allocated(mm, ret);
+
+ /*
+ * Enable the key in the hardware
+ */
+ if (ret > 0)
+ __arch_activate_pkey(ret);
return ret;
}
@@ -96,6 +104,10 @@ static inline int mm_pkey_free(struct mm_struct *mm, int pkey)
if (!mm_pkey_is_allocated(mm, pkey))
return -EINVAL;
+ /*
+ * Disable the key in the hardware
+ */
+ __arch_deactivate_pkey(pkey);
__mm_pkey_free(mm, pkey);
return 0;
--
2.13.6