Messages in this thread Patch in this message | | | Date | Tue, 02 Jun 2009 12:53:14 +0200 | From | Heiko Carstens <> | Subject | [PATCH/RFC 3/4] kprobes: use probe_kernel_write |
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From: Heiko Carstens <heiko.carstens@de.ibm.com>
Use proble_kernel_write() to patch the kernel.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> ---
arch/s390/kernel/kprobes.c | 31 ++----------------------------- 1 file changed, 2 insertions(+), 29 deletions(-)
diff -urpN linux-2.6/arch/s390/kernel/kprobes.c linux-2.6-patched/arch/s390/kernel/kprobes.c --- linux-2.6/arch/s390/kernel/kprobes.c 2009-03-24 00:12:14.000000000 +0100 +++ linux-2.6-patched/arch/s390/kernel/kprobes.c 2009-06-02 10:40:05.000000000 +0200 @@ -25,9 +25,9 @@ #include <linux/preempt.h> #include <linux/stop_machine.h> #include <linux/kdebug.h> +#include <linux/uaccess.h> #include <asm/cacheflush.h> #include <asm/sections.h> -#include <asm/uaccess.h> #include <linux/module.h> DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; @@ -155,35 +155,8 @@ void __kprobes get_instruction_type(stru static int __kprobes swap_instruction(void *aref) { struct ins_replace_args *args = aref; - u32 *addr; - u32 instr; - int err = -EFAULT; - /* - * Text segment is read-only, hence we use stura to bypass dynamic - * address translation to exchange the instruction. Since stura - * always operates on four bytes, but we only want to exchange two - * bytes do some calculations to get things right. In addition we - * shall not cross any page boundaries (vmalloc area!) when writing - * the new instruction. - */ - addr = (u32 *)((unsigned long)args->ptr & -4UL); - if ((unsigned long)args->ptr & 2) - instr = ((*addr) & 0xffff0000) | args->new; - else - instr = ((*addr) & 0x0000ffff) | args->new << 16; - - asm volatile( - " lra %1,0(%1)\n" - "0: stura %2,%1\n" - "1: la %0,0\n" - "2:\n" - EX_TABLE(0b,2b) - : "+d" (err) - : "a" (addr), "d" (instr) - : "memory", "cc"); - - return err; + return probe_kernel_write(args->ptr, &args->new, sizeof(args->new)); } void __kprobes arch_arm_kprobe(struct kprobe *p) --
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