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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2010-05-17 10:00:05 +0200
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>2010-05-17 10:00:15 +0200
commit86f2552bbd0e17b19bb5e9881042533eaea553c7 (patch)
treef520909d953f5d8c7db3dd4c4f2582bd7f7473aa /arch/s390/kernel/ptrace.c
parentcd3b70f5d4d82f85d1e1d6e822f38ae098cf7c72 (diff)
downloadop-kernel-dev-86f2552bbd0e17b19bb5e9881042533eaea553c7.zip
op-kernel-dev-86f2552bbd0e17b19bb5e9881042533eaea553c7.tar.gz
[S390] add breaking event address for user space
Copy the last breaking event address from the lowcore to a new field in the thread_struct on each system entry. Add a new ptrace request PTRACE_GET_LAST_BREAK and a new utrace regset REGSET_LAST_BREAK to query the last breaking event. This is useful for debugging wild branches in user space code. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/ptrace.c')
-rw-r--r--arch/s390/kernel/ptrace.c68
1 files changed, 68 insertions, 0 deletions
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 9f654da..83339d3 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -57,6 +57,7 @@
enum s390_regset {
REGSET_GENERAL,
REGSET_FP,
+ REGSET_LAST_BREAK,
REGSET_GENERAL_EXTENDED,
};
@@ -381,6 +382,10 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
copied += sizeof(unsigned long);
}
return 0;
+ case PTRACE_GET_LAST_BREAK:
+ put_user(task_thread_info(child)->last_break,
+ (unsigned long __user *) data);
+ return 0;
default:
/* Removing high order bit from addr (only for 31 bit). */
addr &= PSW_ADDR_INSN;
@@ -633,6 +638,10 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
copied += sizeof(unsigned int);
}
return 0;
+ case PTRACE_GET_LAST_BREAK:
+ put_user(task_thread_info(child)->last_break,
+ (unsigned int __user *) data);
+ return 0;
}
return compat_ptrace_request(child, request, addr, data);
}
@@ -797,6 +806,28 @@ static int s390_fpregs_set(struct task_struct *target,
return rc;
}
+#ifdef CONFIG_64BIT
+
+static int s390_last_break_get(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
+{
+ if (count > 0) {
+ if (kbuf) {
+ unsigned long *k = kbuf;
+ *k = task_thread_info(target)->last_break;
+ } else {
+ unsigned long __user *u = ubuf;
+ if (__put_user(task_thread_info(target)->last_break, u))
+ return -EFAULT;
+ }
+ }
+ return 0;
+}
+
+#endif
+
static const struct user_regset s390_regsets[] = {
[REGSET_GENERAL] = {
.core_note_type = NT_PRSTATUS,
@@ -814,6 +845,15 @@ static const struct user_regset s390_regsets[] = {
.get = s390_fpregs_get,
.set = s390_fpregs_set,
},
+#ifdef CONFIG_64BIT
+ [REGSET_LAST_BREAK] = {
+ .core_note_type = NT_S390_LAST_BREAK,
+ .n = 1,
+ .size = sizeof(long),
+ .align = sizeof(long),
+ .get = s390_last_break_get,
+ },
+#endif
};
static const struct user_regset_view user_s390_view = {
@@ -948,6 +988,27 @@ static int s390_compat_regs_high_set(struct task_struct *target,
return rc;
}
+static int s390_compat_last_break_get(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
+{
+ compat_ulong_t last_break;
+
+ if (count > 0) {
+ last_break = task_thread_info(target)->last_break;
+ if (kbuf) {
+ unsigned long *k = kbuf;
+ *k = last_break;
+ } else {
+ unsigned long __user *u = ubuf;
+ if (__put_user(last_break, u))
+ return -EFAULT;
+ }
+ }
+ return 0;
+}
+
static const struct user_regset s390_compat_regsets[] = {
[REGSET_GENERAL] = {
.core_note_type = NT_PRSTATUS,
@@ -965,6 +1026,13 @@ static const struct user_regset s390_compat_regsets[] = {
.get = s390_fpregs_get,
.set = s390_fpregs_set,
},
+ [REGSET_LAST_BREAK] = {
+ .core_note_type = NT_S390_LAST_BREAK,
+ .n = 1,
+ .size = sizeof(long),
+ .align = sizeof(long),
+ .get = s390_compat_last_break_get,
+ },
[REGSET_GENERAL_EXTENDED] = {
.core_note_type = NT_S390_HIGH_GPRS,
.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
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