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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2014-03-14 12:01:08 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2014-03-14 12:59:38 +0100
commit818a330c4e1be9c39fa7ca9221e044907d92b4bb (patch)
tree1341793bde170543839a96a71fd72350c8f04c1d /arch/s390
parent443fc8a3e01cef95f2c7c26605457d49e63da6b1 (diff)
s390/ptrace: add support for PTRACE_SINGLEBLOCK
The PTRACE_SINGLEBLOCK option is used to get control whenever the inferior has executed a successful branch. The PER option to implement block stepping is successful-branching event, bit 32 in the PER-event mask. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/include/asm/ptrace.h1
-rw-r--r--arch/s390/include/asm/thread_info.h1
-rw-r--r--arch/s390/include/uapi/asm/ptrace.h6
-rw-r--r--arch/s390/kernel/ptrace.c13
4 files changed, 20 insertions, 1 deletions
diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h
index 9c82cebddabd..f4783c0b7b43 100644
--- a/arch/s390/include/asm/ptrace.h
+++ b/arch/s390/include/asm/ptrace.h
@@ -83,6 +83,7 @@ struct per_struct_kernel {
* These are defined as per linux/ptrace.h, which see.
*/
#define arch_has_single_step() (1)
+#define arch_has_block_step() (1)
#define user_mode(regs) (((regs)->psw.mask & PSW_MASK_PSTATE) != 0)
#define instruction_pointer(regs) ((regs)->psw.addr & PSW_ADDR_INSN)
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index d2e53d667a92..3ccd71b90345 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -92,6 +92,7 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_MEMDIE 18 /* is terminating due to OOM killer */
#define TIF_RESTORE_SIGMASK 19 /* restore signal mask in do_signal() */
#define TIF_SINGLE_STEP 20 /* This task is single stepped */
+#define TIF_BLOCK_STEP 21 /* This task is block stepped */
#define _TIF_SYSCALL (1<<TIF_SYSCALL)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
diff --git a/arch/s390/include/uapi/asm/ptrace.h b/arch/s390/include/uapi/asm/ptrace.h
index 7e0b498a2c2b..a150f4fabe43 100644
--- a/arch/s390/include/uapi/asm/ptrace.h
+++ b/arch/s390/include/uapi/asm/ptrace.h
@@ -403,6 +403,12 @@ typedef struct
#define PTRACE_TE_ABORT_RAND 0x5011
/*
+ * The numbers chosen here are somewhat arbitrary but absolutely MUST
+ * not overlap with any of the number assigned in <linux/ptrace.h>.
+ */
+#define PTRACE_SINGLEBLOCK 12 /* resume execution until next branch */
+
+/*
* PT_PROT definition is loosely based on hppa bsd definition in
* gdb/hppab-nat.c
*/
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index f6be6087a0e9..4ac8fafec95f 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -85,7 +85,10 @@ void update_cr_regs(struct task_struct *task)
/* merge TIF_SINGLE_STEP into user specified PER registers. */
if (test_tsk_thread_flag(task, TIF_SINGLE_STEP)) {
- new.control |= PER_EVENT_IFETCH;
+ if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
+ new.control |= PER_EVENT_BRANCH;
+ else
+ new.control |= PER_EVENT_IFETCH;
#ifdef CONFIG_64BIT
new.control |= PER_CONTROL_SUSPENSION;
new.control |= PER_EVENT_TRANSACTION_END;
@@ -107,14 +110,22 @@ void update_cr_regs(struct task_struct *task)
void user_enable_single_step(struct task_struct *task)
{
+ clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
set_tsk_thread_flag(task, TIF_SINGLE_STEP);
}
void user_disable_single_step(struct task_struct *task)
{
+ clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
}
+void user_enable_block_step(struct task_struct *task)
+{
+ set_tsk_thread_flag(task, TIF_SINGLE_STEP);
+ set_tsk_thread_flag(task, TIF_BLOCK_STEP);
+}
+
/*
* Called by kernel/ptrace.c when detaching..
*