[PATCH 2/2] ARM: cacheflush: return error to userspace when flushing syscall fails
Will Deacon
will.deacon at arm.com
Wed Apr 25 11:54:20 EDT 2012
The cacheflush syscall can fail for two reasons:
(1) The arguments are invalid (nonsensical address range or no VMA)
(2) The region generates a translation fault on a VIPT or PIPT cache
This patch allows do_cache_op to return an error code to userspace in
the case of the above. The various coherent_user_range implementations
are modified to return 0 in the case of VIVT caches or -EFAULT in the
case of an abort on v6/v7 cores.
Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>
Signed-off-by: Will Deacon <will.deacon at arm.com>
---
arch/arm/include/asm/cacheflush.h | 4 ++--
arch/arm/kernel/traps.c | 11 +++++------
arch/arm/mm/cache-v3.S | 1 +
arch/arm/mm/cache-v4.S | 1 +
arch/arm/mm/cache-v4wb.S | 6 +++---
arch/arm/mm/cache-v4wt.S | 1 +
arch/arm/mm/cache-v6.S | 10 ++++------
arch/arm/mm/cache-v7.S | 10 ++++------
arch/arm/mm/proc-arm1020.S | 1 +
arch/arm/mm/proc-arm1020e.S | 1 +
arch/arm/mm/proc-arm1022.S | 1 +
arch/arm/mm/proc-arm1026.S | 1 +
arch/arm/mm/proc-arm920.S | 1 +
arch/arm/mm/proc-arm922.S | 1 +
arch/arm/mm/proc-arm925.S | 1 +
arch/arm/mm/proc-arm926.S | 1 +
arch/arm/mm/proc-arm940.S | 6 +++---
arch/arm/mm/proc-arm946.S | 1 +
arch/arm/mm/proc-feroceon.S | 1 +
arch/arm/mm/proc-mohawk.S | 1 +
20 files changed, 35 insertions(+), 26 deletions(-)
diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h
index 1252a26..004c1bc 100644
--- a/arch/arm/include/asm/cacheflush.h
+++ b/arch/arm/include/asm/cacheflush.h
@@ -101,7 +101,7 @@ struct cpu_cache_fns {
void (*flush_user_range)(unsigned long, unsigned long, unsigned int);
void (*coherent_kern_range)(unsigned long, unsigned long);
- void (*coherent_user_range)(unsigned long, unsigned long);
+ int (*coherent_user_range)(unsigned long, unsigned long);
void (*flush_kern_dcache_area)(void *, size_t);
void (*dma_map_area)(const void *, size_t, int);
@@ -142,7 +142,7 @@ extern void __cpuc_flush_kern_all(void);
extern void __cpuc_flush_user_all(void);
extern void __cpuc_flush_user_range(unsigned long, unsigned long, unsigned int);
extern void __cpuc_coherent_kern_range(unsigned long, unsigned long);
-extern void __cpuc_coherent_user_range(unsigned long, unsigned long);
+extern int __cpuc_coherent_user_range(unsigned long, unsigned long);
extern void __cpuc_flush_dcache_area(void *, size_t);
/*
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 63d402f..3647170 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -479,14 +479,14 @@ static int bad_syscall(int n, struct pt_regs *regs)
return regs->ARM_r0;
}
-static inline void
+static inline int
do_cache_op(unsigned long start, unsigned long end, int flags)
{
struct mm_struct *mm = current->active_mm;
struct vm_area_struct *vma;
if (end < start || flags)
- return;
+ return -EINVAL;
down_read(&mm->mmap_sem);
vma = find_vma(mm, start);
@@ -497,10 +497,10 @@ do_cache_op(unsigned long start, unsigned long end, int flags)
end = vma->vm_end;
up_read(&mm->mmap_sem);
- flush_cache_user_range(start, end);
- return;
+ return flush_cache_user_range(start, end);
}
up_read(&mm->mmap_sem);
+ return -EINVAL;
}
/*
@@ -546,8 +546,7 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)
* the specified region).
*/
case NR(cacheflush):
- do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2);
- return 0;
+ return do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2);
case NR(usr26):
if (!(elf_hwcap & HWCAP_26BIT))
diff --git a/arch/arm/mm/cache-v3.S b/arch/arm/mm/cache-v3.S
index c2301f2..52e35f3 100644
--- a/arch/arm/mm/cache-v3.S
+++ b/arch/arm/mm/cache-v3.S
@@ -78,6 +78,7 @@ ENTRY(v3_coherent_kern_range)
* - end - virtual end address
*/
ENTRY(v3_coherent_user_range)
+ mov r0, #0
mov pc, lr
/*
diff --git a/arch/arm/mm/cache-v4.S b/arch/arm/mm/cache-v4.S
index fd9bb7a..022135d 100644
--- a/arch/arm/mm/cache-v4.S
+++ b/arch/arm/mm/cache-v4.S
@@ -88,6 +88,7 @@ ENTRY(v4_coherent_kern_range)
* - end - virtual end address
*/
ENTRY(v4_coherent_user_range)
+ mov r0, #0
mov pc, lr
/*
diff --git a/arch/arm/mm/cache-v4wb.S b/arch/arm/mm/cache-v4wb.S
index 4f2c141..8f1eeae 100644
--- a/arch/arm/mm/cache-v4wb.S
+++ b/arch/arm/mm/cache-v4wb.S
@@ -167,9 +167,9 @@ ENTRY(v4wb_coherent_user_range)
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
- mov ip, #0
- mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache
- mcr p15, 0, ip, c7, c10, 4 @ drain WB
+ mov r0, #0
+ mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
+ mcr p15, 0, r0, c7, c10, 4 @ drain WB
mov pc, lr
diff --git a/arch/arm/mm/cache-v4wt.S b/arch/arm/mm/cache-v4wt.S
index 4d7b467..b34a5f9 100644
--- a/arch/arm/mm/cache-v4wt.S
+++ b/arch/arm/mm/cache-v4wt.S
@@ -125,6 +125,7 @@ ENTRY(v4wt_coherent_user_range)
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
+ mov r0, #0
mov pc, lr
/*
diff --git a/arch/arm/mm/cache-v6.S b/arch/arm/mm/cache-v6.S
index 74c2e5a..4b10760 100644
--- a/arch/arm/mm/cache-v6.S
+++ b/arch/arm/mm/cache-v6.S
@@ -12,6 +12,7 @@
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/assembler.h>
+#include <asm/errno.h>
#include <asm/unwind.h>
#include "proc-macros.S"
@@ -135,7 +136,6 @@ ENTRY(v6_coherent_user_range)
1:
USER( mcr p15, 0, r0, c7, c10, 1 ) @ clean D line
add r0, r0, #CACHE_LINE_SIZE
-2:
cmp r0, r1
blo 1b
#endif
@@ -154,13 +154,11 @@ ENTRY(v6_coherent_user_range)
/*
* Fault handling for the cache operation above. If the virtual address in r0
- * isn't mapped, just try the next page.
+ * isn't mapped, fail with -EFAULT.
*/
9001:
- mov r0, r0, lsr #12
- mov r0, r0, lsl #12
- add r0, r0, #4096
- b 2b
+ mov r0, #-EFAULT
+ mov pc, lr
UNWIND(.fnend )
ENDPROC(v6_coherent_user_range)
ENDPROC(v6_coherent_kern_range)
diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
index a655d3d..39e3fb3 100644
--- a/arch/arm/mm/cache-v7.S
+++ b/arch/arm/mm/cache-v7.S
@@ -13,6 +13,7 @@
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/assembler.h>
+#include <asm/errno.h>
#include <asm/unwind.h>
#include "proc-macros.S"
@@ -198,7 +199,6 @@ ENTRY(v7_coherent_user_range)
add r12, r12, r2
cmp r12, r1
blo 2b
-3:
mov r0, #0
ALT_SMP(mcr p15, 0, r0, c7, c1, 6) @ invalidate BTB Inner Shareable
ALT_UP(mcr p15, 0, r0, c7, c5, 6) @ invalidate BTB
@@ -208,13 +208,11 @@ ENTRY(v7_coherent_user_range)
/*
* Fault handling for the cache operation above. If the virtual address in r0
- * isn't mapped, just try the next page.
+ * isn't mapped, fail with -EFAULT.
*/
9001:
- mov r12, r12, lsr #12
- mov r12, r12, lsl #12
- add r12, r12, #4096
- b 3b
+ mov r0, #-EFAULT
+ mov pc, lr
UNWIND(.fnend )
ENDPROC(v7_coherent_kern_range)
ENDPROC(v7_coherent_user_range)
diff --git a/arch/arm/mm/proc-arm1020.S b/arch/arm/mm/proc-arm1020.S
index 2349513..0650bb8 100644
--- a/arch/arm/mm/proc-arm1020.S
+++ b/arch/arm/mm/proc-arm1020.S
@@ -241,6 +241,7 @@ ENTRY(arm1020_coherent_user_range)
cmp r0, r1
blo 1b
mcr p15, 0, ip, c7, c10, 4 @ drain WB
+ mov r0, #0
mov pc, lr
/*
diff --git a/arch/arm/mm/proc-arm1020e.S b/arch/arm/mm/proc-arm1020e.S
index c244b06..4188478 100644
--- a/arch/arm/mm/proc-arm1020e.S
+++ b/arch/arm/mm/proc-arm1020e.S
@@ -235,6 +235,7 @@ ENTRY(arm1020e_coherent_user_range)
cmp r0, r1
blo 1b
mcr p15, 0, ip, c7, c10, 4 @ drain WB
+ mov r0, #0
mov pc, lr
/*
diff --git a/arch/arm/mm/proc-arm1022.S b/arch/arm/mm/proc-arm1022.S
index 38fe22e..33c6882 100644
--- a/arch/arm/mm/proc-arm1022.S
+++ b/arch/arm/mm/proc-arm1022.S
@@ -224,6 +224,7 @@ ENTRY(arm1022_coherent_user_range)
cmp r0, r1
blo 1b
mcr p15, 0, ip, c7, c10, 4 @ drain WB
+ mov r0, #0
mov pc, lr
/*
diff --git a/arch/arm/mm/proc-arm1026.S b/arch/arm/mm/proc-arm1026.S
index 3eb9c3c..fbc1d5f 100644
--- a/arch/arm/mm/proc-arm1026.S
+++ b/arch/arm/mm/proc-arm1026.S
@@ -218,6 +218,7 @@ ENTRY(arm1026_coherent_user_range)
cmp r0, r1
blo 1b
mcr p15, 0, ip, c7, c10, 4 @ drain WB
+ mov r0, #0
mov pc, lr
/*
diff --git a/arch/arm/mm/proc-arm920.S b/arch/arm/mm/proc-arm920.S
index cb941ae..1a8c138 100644
--- a/arch/arm/mm/proc-arm920.S
+++ b/arch/arm/mm/proc-arm920.S
@@ -210,6 +210,7 @@ ENTRY(arm920_coherent_user_range)
cmp r0, r1
blo 1b
mcr p15, 0, r0, c7, c10, 4 @ drain WB
+ mov r0, #0
mov pc, lr
/*
diff --git a/arch/arm/mm/proc-arm922.S b/arch/arm/mm/proc-arm922.S
index 4ec0e07..4c44d7e 100644
--- a/arch/arm/mm/proc-arm922.S
+++ b/arch/arm/mm/proc-arm922.S
@@ -212,6 +212,7 @@ ENTRY(arm922_coherent_user_range)
cmp r0, r1
blo 1b
mcr p15, 0, r0, c7, c10, 4 @ drain WB
+ mov r0, #0
mov pc, lr
/*
diff --git a/arch/arm/mm/proc-arm925.S b/arch/arm/mm/proc-arm925.S
index 9dccd9a..ec5b118 100644
--- a/arch/arm/mm/proc-arm925.S
+++ b/arch/arm/mm/proc-arm925.S
@@ -258,6 +258,7 @@ ENTRY(arm925_coherent_user_range)
cmp r0, r1
blo 1b
mcr p15, 0, r0, c7, c10, 4 @ drain WB
+ mov r0, #0
mov pc, lr
/*
diff --git a/arch/arm/mm/proc-arm926.S b/arch/arm/mm/proc-arm926.S
index 820259b..c31e62c 100644
--- a/arch/arm/mm/proc-arm926.S
+++ b/arch/arm/mm/proc-arm926.S
@@ -221,6 +221,7 @@ ENTRY(arm926_coherent_user_range)
cmp r0, r1
blo 1b
mcr p15, 0, r0, c7, c10, 4 @ drain WB
+ mov r0, #0
mov pc, lr
/*
diff --git a/arch/arm/mm/proc-arm940.S b/arch/arm/mm/proc-arm940.S
index 9fdc0a1..a613a7d 100644
--- a/arch/arm/mm/proc-arm940.S
+++ b/arch/arm/mm/proc-arm940.S
@@ -160,7 +160,7 @@ ENTRY(arm940_coherent_user_range)
* - size - region size
*/
ENTRY(arm940_flush_kern_dcache_area)
- mov ip, #0
+ mov r0, #0
mov r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
2: mcr p15, 0, r3, c7, c14, 2 @ clean/flush D index
@@ -168,8 +168,8 @@ ENTRY(arm940_flush_kern_dcache_area)
bcs 2b @ entries 63 to 0
subs r1, r1, #1 << 4
bcs 1b @ segments 7 to 0
- mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache
- mcr p15, 0, ip, c7, c10, 4 @ drain WB
+ mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
+ mcr p15, 0, r0, c7, c10, 4 @ drain WB
mov pc, lr
/*
diff --git a/arch/arm/mm/proc-arm946.S b/arch/arm/mm/proc-arm946.S
index f684cfe..9f4f299 100644
--- a/arch/arm/mm/proc-arm946.S
+++ b/arch/arm/mm/proc-arm946.S
@@ -190,6 +190,7 @@ ENTRY(arm946_coherent_user_range)
cmp r0, r1
blo 1b
mcr p15, 0, r0, c7, c10, 4 @ drain WB
+ mov r0, #0
mov pc, lr
/*
diff --git a/arch/arm/mm/proc-feroceon.S b/arch/arm/mm/proc-feroceon.S
index ba3c500..23a8e4c 100644
--- a/arch/arm/mm/proc-feroceon.S
+++ b/arch/arm/mm/proc-feroceon.S
@@ -232,6 +232,7 @@ ENTRY(feroceon_coherent_user_range)
cmp r0, r1
blo 1b
mcr p15, 0, r0, c7, c10, 4 @ drain WB
+ mov r0, #0
mov pc, lr
/*
diff --git a/arch/arm/mm/proc-mohawk.S b/arch/arm/mm/proc-mohawk.S
index cdfedc5..b047546 100644
--- a/arch/arm/mm/proc-mohawk.S
+++ b/arch/arm/mm/proc-mohawk.S
@@ -193,6 +193,7 @@ ENTRY(mohawk_coherent_user_range)
cmp r0, r1
blo 1b
mcr p15, 0, r0, c7, c10, 4 @ drain WB
+ mov r0, #0
mov pc, lr
/*
--
1.7.4.1
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