The following commit has been merged in the linux branch: commit 32cfb1b16f2b68d2296536811cadfffe26a06c1b Author: Catalin Marinas catalin.marinas@arm.com Date: Tue Oct 6 17:57:09 2009 +0100
ARM: 5746/1: Handle possible translation errors in ARMv6/v7 coherent_user_range
This is needed because applications using the sys_cacheflush system call can pass a memory range which isn't mapped yet even though the corresponding vma is valid. The patch also adds unwinding annotations for correct backtraces from the coherent_user_range() functions.
Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Russell King rmk+kernel@arm.linux.org.uk
diff --git a/arch/arm/mm/cache-v6.S b/arch/arm/mm/cache-v6.S index 8f5c13f..295e25d 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/unwind.h>
#include "proc-macros.S"
@@ -121,11 +122,13 @@ ENTRY(v6_coherent_kern_range) * - the Icache does not read data from the write buffer */ ENTRY(v6_coherent_user_range) - + UNWIND(.fnstart ) #ifdef HARVARD_CACHE bic r0, r0, #CACHE_LINE_SIZE - 1 -1: mcr p15, 0, r0, c7, c10, 1 @ clean D line +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 @@ -143,6 +146,19 @@ ENTRY(v6_coherent_user_range) mov pc, lr
/* + * Fault handling for the cache operation above. If the virtual address in r0 + * isn't mapped, just try the next page. + */ +9001: + mov r0, r0, lsr #12 + mov r0, r0, lsl #12 + add r0, r0, #4096 + b 2b + UNWIND(.fnend ) +ENDPROC(v6_coherent_user_range) +ENDPROC(v6_coherent_kern_range) + +/* * v6_flush_kern_dcache_page(kaddr) * * Ensure that the data held in the page kaddr is written back diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S index bda0ec3..e1bd975 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/unwind.h>
#include "proc-macros.S"
@@ -153,13 +154,16 @@ ENTRY(v7_coherent_kern_range) * - the Icache does not read data from the write buffer */ ENTRY(v7_coherent_user_range) + UNWIND(.fnstart ) dcache_line_size r2, r3 sub r3, r2, #1 bic r0, r0, r3 -1: mcr p15, 0, r0, c7, c11, 1 @ clean D line to the point of unification +1: + USER( mcr p15, 0, r0, c7, c11, 1 ) @ clean D line to the point of unification dsb - mcr p15, 0, r0, c7, c5, 1 @ invalidate I line + USER( mcr p15, 0, r0, c7, c5, 1 ) @ invalidate I line add r0, r0, r2 +2: cmp r0, r1 blo 1b mov r0, #0 @@ -167,6 +171,17 @@ ENTRY(v7_coherent_user_range) dsb isb mov pc, lr + +/* + * Fault handling for the cache operation above. If the virtual address in r0 + * isn't mapped, just try the next page. + */ +9001: + mov r0, r0, lsr #12 + mov r0, r0, lsl #12 + add r0, r0, #4096 + b 2b + UNWIND(.fnend ) ENDPROC(v7_coherent_kern_range) ENDPROC(v7_coherent_user_range)