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microblaze: Fix copy_to_user_page macro 

copy_to_user_page macro is used in mm/memory.c:access_process_vm
function. This function is called from ptrace code (POKETEXT, POKEDATA)
which write data to memory. Microblaze handle physical address for
caches that's why there is virt_to_phys conversion.

There is potential one location which can caused the problem on WB system.

The important is take a look at write PTRACEs requests
(POKE/TEXT, DATA, USR).

Note:
Majority of Microblaze PTRACE code is moved to generic location
in newer kernel version that's why this solution should work on
the newest kernel version too.

linux/io.h is in cacheflush because of mm/nommu.c

Tested on a WB system - hello world debugging.

Signed-off-by: Michal Simek <monstr@monstr.eu>
This commit is contained in:
Michal Simek 2010-05-24 12:13:24 +02:00
parent e05816679b
commit 6847ba91a1
2 changed files with 19 additions and 2 deletions
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4
arch/microblaze/include/asm/cacheflush.h
View File

@ -103,8 +103,10 @@ do { \
#define copy_to_user_page(vma, page, vaddr, dst, src, len) \
do { \
u32 addr = virt_to_phys(dst); \
invalidate_icache_range((unsigned) (addr), (unsigned) (addr) + (len));\
memcpy((dst), (src), (len)); \
flush_icache_range((unsigned) (dst), (unsigned) (dst) + (len)); \
flush_dcache_range((unsigned) (addr), (unsigned) (addr) + (len));\
} while (0)
#define copy_from_user_page(vma, page, vaddr, dst, src, len) \

17
arch/microblaze/kernel/ptrace.c
View File

@ -38,6 +38,8 @@
#include <asm/processor.h>
#include <linux/uaccess.h>
#include <asm/asm-offsets.h>
#include <asm/cacheflush.h>
#include <asm/io.h>
/* Returns the address where the register at REG_OFFS in P is stashed away. */
static microblaze_reg_t *reg_save_addr(unsigned reg_offs,
@ -101,8 +103,21 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
microblaze_reg_t *reg_addr = reg_save_addr(addr, child);
if (request == PTRACE_PEEKUSR)
val = *reg_addr;
else
else {
#if 1
*reg_addr = data;
#else
/* MS potential problem on WB system
* Be aware that reg_addr is virtual address
* virt_to_phys conversion is necessary.
* This could be sensible solution.
*/
u32 paddr = virt_to_phys((u32)reg_addr);
invalidate_icache_range(paddr, paddr + 4);
*reg_addr = data;
flush_dcache_range(paddr, paddr + 4);
#endif
}
} else
rval = -EIO;