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authorJames Bottomley <jejb@mulgrave.il.steeleye.com>2007-02-10 13:45:43 -0600
committerJames Bottomley <jejb@mulgrave.il.steeleye.com>2007-02-10 13:45:43 -0600
commit81b7bbd1932a04869d4c8635a75222dfc6089f96 (patch)
tree285ae868a1e3a41fb0dbfe346c28e380949bcb55 /arch/s390/kernel/kprobes.c
parent98051995ab44b993f992946055edc6115351f725 (diff)
parent66efc5a7e3061c3597ac43a8bb1026488d57e66b (diff)
downloadlinux-81b7bbd1932a04869d4c8635a75222dfc6089f96.tar.gz
Merge branch 'linus'
Conflicts: drivers/scsi/ipr.c Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'arch/s390/kernel/kprobes.c')
-rw-r--r--arch/s390/kernel/kprobes.c32
1 files changed, 26 insertions, 6 deletions
diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
index 576368c4f605..a466bab6677e 100644
--- a/arch/s390/kernel/kprobes.c
+++ b/arch/s390/kernel/kprobes.c
@@ -155,15 +155,34 @@ void __kprobes get_instruction_type(struct arch_specific_insn *ainsn)
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 *)ALIGN((unsigned long)args->ptr, 4);
+ if ((unsigned long)args->ptr & 2)
+ instr = ((*addr) & 0xffff0000) | args->new;
+ else
+ instr = ((*addr) & 0x0000ffff) | args->new << 16;
+
asm volatile(
- "0: mvc 0(2,%2),0(%3)\n"
- "1: la %0,0\n"
+ " lra %1,0(%1)\n"
+ "0: stura %2,%1\n"
+ "1: la %0,0\n"
"2:\n"
EX_TABLE(0b,2b)
- : "+d" (err), "=m" (*args->ptr)
- : "a" (args->ptr), "a" (&args->new), "m" (args->new));
+ : "+d" (err)
+ : "a" (addr), "d" (instr)
+ : "memory", "cc");
+
return err;
}
@@ -356,7 +375,7 @@ no_kprobe:
* - When the probed function returns, this probe
* causes the handlers to fire
*/
-void __kprobes kretprobe_trampoline_holder(void)
+void kretprobe_trampoline_holder(void)
{
asm volatile(".global kretprobe_trampoline\n"
"kretprobe_trampoline: bcr 0,0\n");
@@ -365,7 +384,8 @@ void __kprobes kretprobe_trampoline_holder(void)
/*
* Called when the probe at kretprobe trampoline is hit
*/
-int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
+static int __kprobes trampoline_probe_handler(struct kprobe *p,
+ struct pt_regs *regs)
{
struct kretprobe_instance *ri = NULL;
struct hlist_head *head, empty_rp;