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ARM: 7408/1: cacheflush: return error to userspace when flushing syscall fails 

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@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Will Deacon 2012-04-27 13:08:53 +01:00 committed by Russell King
parent 435a7ef52d
commit c5102f5935
20 changed files with 35 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/arm/include/asm/cacheflush.h
View File

@ -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);
/*

11
arch/arm/kernel/traps.c
View File

@ -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))

1
arch/arm/mm/cache-v3.S
View File

@ -78,6 +78,7 @@ ENTRY(v3_coherent_kern_range)
* - end - virtual end address
*/
ENTRY(v3_coherent_user_range)
mov r0, #0
mov pc, lr
/*

1
arch/arm/mm/cache-v4.S
View File

@ -88,6 +88,7 @@ ENTRY(v4_coherent_kern_range)
* - end - virtual end address
*/
ENTRY(v4_coherent_user_range)
mov r0, #0
mov pc, lr
/*

6
arch/arm/mm/cache-v4wb.S
View File

@ -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

1
arch/arm/mm/cache-v4wt.S
View File

@ -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
/*

10
arch/arm/mm/cache-v6.S
View File

@ -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)

10
arch/arm/mm/cache-v7.S
View File

@ -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)

1
arch/arm/mm/proc-arm1020.S
View File

@ -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
/*

1
arch/arm/mm/proc-arm1020e.S
View File

@ -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
/*

1
arch/arm/mm/proc-arm1022.S
View File

@ -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
/*

1
arch/arm/mm/proc-arm1026.S
View File

@ -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
/*

1
arch/arm/mm/proc-arm920.S
View File

@ -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
/*

1
arch/arm/mm/proc-arm922.S
View File

@ -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
/*

1
arch/arm/mm/proc-arm925.S
View File

@ -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
/*

1
arch/arm/mm/proc-arm926.S
View File

@ -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
/*

6
arch/arm/mm/proc-arm940.S
View File

@ -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
/*

1
arch/arm/mm/proc-arm946.S
View File

@ -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
/*

1
arch/arm/mm/proc-feroceon.S
View File

@ -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
/*

1
arch/arm/mm/proc-mohawk.S
View File

@ -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
/*