lkml.org 
[lkml]   [2017]   [Nov]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v9 07/51] powerpc: cleanup AMR, IAMR when a key is allocated or freed
Date
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>
---
arch/powerpc/include/asm/pkeys.h | 12 ++++++++++++
1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index e5deac7..0d00a54 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -69,6 +69,8 @@ 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
@@ -96,6 +98,12 @@ 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;
}

@@ -107,6 +115,10 @@ 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;
--
1.7.1
\
 
 \ /
  Last update: 2017-11-06 10:40    [W:0.177 / U:0.524 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site