From: Russell King <rmk+kernel@armlinux.org.uk>
To: linux-arm-kernel@lists.infradead.org,
Tomas Paukrt <tomas.paukrt@advantech.cz>
Cc: Will Deacon <will@kernel.org>, Alexander Viro <viro@zeniv.linux.org.uk>
Subject: [PATCH 2/3] ARM: uaccess: integrate uaccess_save and uaccess_restore
Date: Mon, 04 May 2020 14:35:05 +0100 [thread overview]
Message-ID: <E1jVbFR-00076Y-42@rmk-PC.armlinux.org.uk> (raw)
In-Reply-To: <20200504133435.GD1551@shell.armlinux.org.uk>
Integrate uaccess_save / uaccess_restore macros into the new
uaccess_entry / uaccess_exit macros respectively.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/include/asm/uaccess-asm.h | 30 +++++++++++++-----------------
1 file changed, 13 insertions(+), 17 deletions(-)
diff --git a/arch/arm/include/asm/uaccess-asm.h b/arch/arm/include/asm/uaccess-asm.h
index d475e3e8145d..e46468b91eaa 100644
--- a/arch/arm/include/asm/uaccess-asm.h
+++ b/arch/arm/include/asm/uaccess-asm.h
@@ -67,30 +67,23 @@
#endif
.endm
- .macro uaccess_save, tmp
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
- mrc p15, 0, \tmp, c3, c0, 0
- str \tmp, [sp, #SVC_DACR]
-#endif
- .endm
-
- .macro uaccess_restore
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
- ldr r0, [sp, #SVC_DACR]
- mcr p15, 0, r0, c3, c0, 0
+#define DACR(x...) x
+#else
+#define DACR(x...)
#endif
- .endm
/*
* Save the address limit on entry to a privileged exception and
* if using PAN, save and disable usermode access.
*/
.macro uaccess_entry, tsk, tmp0, tmp1, tmp2, disable
- ldr \tmp0, [\tsk, #TI_ADDR_LIMIT]
- mov \tmp1, #TASK_SIZE
- str \tmp1, [\tsk, #TI_ADDR_LIMIT]
- str \tmp0, [sp, #SVC_ADDR_LIMIT]
- uaccess_save \tmp0
+ ldr \tmp1, [\tsk, #TI_ADDR_LIMIT]
+ mov \tmp2, #TASK_SIZE
+ str \tmp2, [\tsk, #TI_ADDR_LIMIT]
+ DACR( mrc p15, 0, \tmp0, c3, c0, 0)
+ DACR( str \tmp0, [sp, #SVC_DACR])
+ str \tmp1, [sp, #SVC_ADDR_LIMIT]
.if \disable
uaccess_disable \tmp0
.endif
@@ -99,8 +92,11 @@
/* Restore the user access state previously saved by uaccess_entry */
.macro uaccess_exit, tsk, tmp0, tmp1
ldr \tmp1, [sp, #SVC_ADDR_LIMIT]
- uaccess_restore
+ DACR( ldr \tmp0, [sp, #SVC_DACR])
str \tmp1, [\tsk, #TI_ADDR_LIMIT]
+ DACR( mcr p15, 0, \tmp0, c3, c0, 0)
.endm
+#undef DACR
+
#endif /* __ASM_UACCESS_ASM_H__ */
--
2.20.1
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next prev parent reply other threads:[~2020-05-04 13:37 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-04 13:34 [PATCH 0/3] Fix uaccess kernel protection on ARMv5 and earlier Russell King - ARM Linux admin
2020-05-04 13:34 ` [PATCH 1/3] ARM: uaccess: consolidate uaccess asm to asm/uaccess-asm.h Russell King
2020-05-04 13:35 ` Russell King [this message]
2020-05-04 13:35 ` [PATCH 3/3] ARM: uaccess: fix DACR mismatch with nested exceptions Russell King
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