Subjective of course, but imho makes the code more readable.
No functional changes (I hope), PTRACE_SYSEMU/PTRACE_SYSEMU_SINGLESTEP
logic still waits for implementation.
Rewrite the code to use switch(request) instead of multiple "if" checks.
This also consolidates some ifdef's and kills is_xxx(request).
Also, factor our utrace_set_events() calls.
static int ptrace_resume(struct utrace_engine *engine,
struct task_struct *tracee, long request, long
data)
{
enum utrace_resume_action action;
enum utrace_syscall_action syscall;
unsigned long events;
if (!valid_signal(data))
return -EIO;
syscall = UTRACE_SYSCALL_RUN;
events = engine->flags & ~UTRACE_EVENT_SYSCALL;
action = UTRACE_RESUME;
switch (request) {
#ifdef PTRACE_SINGLEBLOCK
case PTRACE_SINGLEBLOCK:
if (unlikely(!arch_has_block_step()))
return -EIO;
action = UTRACE_BLOCKSTEP;
break;
#endif
#ifdef PTRACE_SINGLESTEP
case PTRACE_SINGLESTEP:
if (unlikely(!arch_has_single_step()))
return -EIO;
action = UTRACE_SINGLESTEP;
break;
#endif
#ifdef PTRACE_SYSEMU
case PTRACE_SYSEMU_SINGLESTEP:
if (unlikely(!arch_has_single_step()))
return -EIO;
action = UTRACE_SINGLESTEP;
case PTRACE_SYSEMU:
syscall = UTRACE_SYSCALL_ABORT;
/* fallthrough */
#endif
case PTRACE_SYSCALL:
events |= UTRACE_EVENT_SYSCALL;
break;
}
if (events != engine->flags &&
utrace_set_events(tracee, engine, events))
return -ESRCH;
do_ptrace_resume(engine, tracee, action, request, data);
return 0;
}
---
kernel/ptrace.c | 78 +++++++++++++++++++++++++-------------------------------
1 file changed, 35 insertions(+), 43 deletions(-)
--- PU/kernel/ptrace.c~102_RESUME_CLEANUP_REQUEST_PROCESSING 2009-10-18
18:34:55.000000000 +0200
+++ PU/kernel/ptrace.c 2009-10-18 18:35:30.000000000 +0200
@@ -882,24 +882,6 @@ static int ptrace_rw_siginfo(struct task
}
}
-#ifdef PTRACE_SINGLESTEP
-#define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
-#else
-#define is_singlestep(request) 0
-#endif
-
-#ifdef PTRACE_SINGLEBLOCK
-#define is_singleblock(request) ((request) ==
PTRACE_SINGLEBLOCK)
-#else
-#define is_singleblock(request) 0
-#endif
-
-#ifdef PTRACE_SYSEMU
-#define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
-#else
-#define is_sysemu_singlestep(request) 0
-#endif
-
static void do_ptrace_notify_stop(struct ptrace_context *context,
struct task_struct *tracee)
{
@@ -1022,47 +1004,57 @@ static void do_ptrace_resume(struct utra
}
static int ptrace_resume(struct utrace_engine *engine,
- struct task_struct *child, long request, long data)
+ struct task_struct *tracee, long request, long data)
{
enum utrace_resume_action action;
enum utrace_syscall_action syscall;
- int ret = 0;
+ unsigned long events;
if (!valid_signal(data))
return -EIO;
syscall = UTRACE_SYSCALL_RUN;
-#ifdef PTRACE_SYSEMU
- if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
- syscall = UTRACE_SYSCALL_ABORT;
-#endif
-
- if (syscall != UTRACE_SYSCALL_RUN || request == PTRACE_SYSCALL) {
- if (!(engine->flags & UTRACE_EVENT_SYSCALL) &&
- utrace_set_events(child, engine,
- engine->flags | UTRACE_EVENT_SYSCALL))
- ret = -ESRCH;
- } else if (engine->flags & UTRACE_EVENT(SYSCALL_ENTRY)) {
- if (utrace_set_events(child, engine,
- engine->flags & ~UTRACE_EVENT_SYSCALL))
- ret = -ESRCH;
- }
+ events = engine->flags & ~UTRACE_EVENT_SYSCALL;
+ action = UTRACE_RESUME;
- action = UTRACE_RESUME;
- if (is_singleblock(request)) {
+ switch (request) {
+#ifdef PTRACE_SINGLEBLOCK
+ case PTRACE_SINGLEBLOCK:
if (unlikely(!arch_has_block_step()))
- ret = -EIO;
+ return -EIO;
action = UTRACE_BLOCKSTEP;
- } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
+ break;
+#endif
+
+#ifdef PTRACE_SINGLESTEP
+ case PTRACE_SINGLESTEP:
if (unlikely(!arch_has_single_step()))
- ret = -EIO;
+ return -EIO;
action = UTRACE_SINGLESTEP;
+ break;
+#endif
+
+#ifdef PTRACE_SYSEMU
+ case PTRACE_SYSEMU_SINGLESTEP:
+ if (unlikely(!arch_has_single_step()))
+ return -EIO;
+ action = UTRACE_SINGLESTEP;
+ case PTRACE_SYSEMU:
+ syscall = UTRACE_SYSCALL_ABORT;
+ /* fallthrough */
+#endif
+
+ case PTRACE_SYSCALL:
+ events |= UTRACE_EVENT_SYSCALL;
+ break;
}
- if (!ret)
- do_ptrace_resume(engine, child, action, request, data);
+ if (events != engine->flags &&
+ utrace_set_events(tracee, engine, events))
+ return -ESRCH;
- return ret;
+ do_ptrace_resume(engine, tracee, action, request, data);
+ return 0;
}
int ptrace_request(struct task_struct *child, long request,
