Blackfin: initial tracehook support
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index 970df5b..c078849 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -24,6 +24,7 @@
config BLACKFIN
def_bool y
select HAVE_ARCH_KGDB
+ select HAVE_ARCH_TRACEHOOK
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER
select HAVE_FUNCTION_TRACE_MCOUNT_TEST
diff --git a/arch/blackfin/include/asm/ptrace.h b/arch/blackfin/include/asm/ptrace.h
index c1aebdb..aaa1c6c 100644
--- a/arch/blackfin/include/asm/ptrace.h
+++ b/arch/blackfin/include/asm/ptrace.h
@@ -24,6 +24,8 @@
#ifndef __ASSEMBLY__
+struct task_struct;
+
/* this struct defines the way the registers are stored on the
stack during a system call. */
@@ -101,9 +103,30 @@
master interrupt enable. */
#define user_mode(regs) (!(((regs)->ipend & ~0x10) & (((regs)->ipend & ~0x10) - 1)))
#define instruction_pointer(regs) ((regs)->pc)
+#define user_stack_pointer(regs) ((regs)->usp)
#define profile_pc(regs) instruction_pointer(regs)
extern void show_regs(struct pt_regs *);
+#define arch_has_single_step() (1)
+extern void user_enable_single_step(struct task_struct *child);
+extern void user_disable_single_step(struct task_struct *child);
+/* common code demands this function */
+#define ptrace_disable(child) user_disable_single_step(child)
+
+/*
+ * Get the address of the live pt_regs for the specified task.
+ * These are saved onto the top kernel stack when the process
+ * is not running.
+ *
+ * Note: if a user thread is execve'd from kernel space, the
+ * kernel stack will not be empty on entry to the kernel, so
+ * ptracing these tasks will fail.
+ */
+#define task_pt_regs(task) \
+ (struct pt_regs *) \
+ ((unsigned long)task_stack_page(task) + \
+ (THREAD_SIZE - sizeof(struct pt_regs)))
+
#endif /* __KERNEL__ */
#endif /* __ASSEMBLY__ */
diff --git a/arch/blackfin/include/asm/syscall.h b/arch/blackfin/include/asm/syscall.h
new file mode 100644
index 0000000..4921a48
--- /dev/null
+++ b/arch/blackfin/include/asm/syscall.h
@@ -0,0 +1,96 @@
+/*
+ * Magic syscall break down functions
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#ifndef __ASM_BLACKFIN_SYSCALL_H__
+#define __ASM_BLACKFIN_SYSCALL_H__
+
+/*
+ * Blackfin syscalls are simple:
+ * enter:
+ * p0: syscall number
+ * r{0,1,2,3,4,5}: syscall args 0,1,2,3,4,5
+ * exit:
+ * r0: return/error value
+ */
+
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <asm/ptrace.h>
+
+static inline long
+syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
+{
+ return regs->p0;
+}
+
+static inline void
+syscall_rollback(struct task_struct *task, struct pt_regs *regs)
+{
+ regs->p0 = regs->orig_p0;
+}
+
+static inline long
+syscall_get_error(struct task_struct *task, struct pt_regs *regs)
+{
+ return IS_ERR_VALUE(regs->r0) ? regs->r0 : 0;
+}
+
+static inline long
+syscall_get_return_value(struct task_struct *task, struct pt_regs *regs)
+{
+ return regs->r0;
+}
+
+static inline void
+syscall_set_return_value(struct task_struct *task, struct pt_regs *regs,
+ int error, long val)
+{
+ regs->r0 = error ? -error : val;
+}
+
+/**
+ * syscall_get_arguments()
+ * @task: unused
+ * @regs: the register layout to extract syscall arguments from
+ * @i: first syscall argument to extract
+ * @n: number of syscall arguments to extract
+ * @args: array to return the syscall arguments in
+ *
+ * args[0] gets i'th argument, args[n - 1] gets the i+n-1'th argument
+ */
+static inline void
+syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
+ unsigned int i, unsigned int n, unsigned long *args)
+{
+ /*
+ * Assume the ptrace layout doesn't change -- r5 is first in memory,
+ * then r4, ..., then r0. So we simply reverse the ptrace register
+ * array in memory to store into the args array.
+ */
+ long *aregs = ®s->r0 - i;
+
+ BUG_ON(i > 5 || i + n > 6);
+
+ while (n--)
+ *args++ = *aregs--;
+}
+
+/* See syscall_get_arguments() comments */
+static inline void
+syscall_set_arguments(struct task_struct *task, struct pt_regs *regs,
+ unsigned int i, unsigned int n, const unsigned long *args)
+{
+ long *aregs = ®s->r0 - i;
+
+ BUG_ON(i > 5 || i + n > 6);
+
+ while (n--)
+ *aregs-- = *args++;
+}
+
+#endif
diff --git a/arch/blackfin/kernel/ptrace.c b/arch/blackfin/kernel/ptrace.c
index 92b4ca0..0618b828 100644
--- a/arch/blackfin/kernel/ptrace.c
+++ b/arch/blackfin/kernel/ptrace.c
@@ -1,6 +1,6 @@
/*
* linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
- * these modifications are Copyright 2004-2009 Analog Devices Inc.
+ * these modifications are Copyright 2004-2010 Analog Devices Inc.
*
* Licensed under the GPL-2
*/
@@ -15,6 +15,7 @@
#include <linux/user.h>
#include <linux/regset.h>
#include <linux/signal.h>
+#include <linux/tracehook.h>
#include <linux/uaccess.h>
#include <asm/page.h>
@@ -32,25 +33,6 @@
* in exit.c or in signal.c.
*/
-/* Find the stack offset for a register, relative to thread.esp0. */
-#define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg)
-
-/*
- * Get the address of the live pt_regs for the specified task.
- * These are saved onto the top kernel stack when the process
- * is not running.
- *
- * Note: if a user thread is execve'd from kernel space, the
- * kernel stack will not be empty on entry to the kernel, so
- * ptracing these tasks will fail.
- */
-static inline struct pt_regs *task_pt_regs(struct task_struct *task)
-{
- return (struct pt_regs *)
- ((unsigned long)task_stack_page(task) +
- (THREAD_SIZE - sizeof(struct pt_regs)));
-}
-
/*
* Get contents of register REGNO in task TASK.
*/
@@ -234,18 +216,13 @@
return &user_bfin_native_view;
}
-void ptrace_enable(struct task_struct *child)
+void user_enable_single_step(struct task_struct *child)
{
struct pt_regs *regs = task_pt_regs(child);
regs->syscfg |= SYSCFG_SSSTEP;
}
-/*
- * Called by kernel/ptrace.c when detaching..
- *
- * Make sure the single step bit is not set.
- */
-void ptrace_disable(struct task_struct *child)
+void user_disable_single_step(struct task_struct *child)
{
struct pt_regs *regs = task_pt_regs(child);
regs->syscfg &= ~SYSCFG_SSSTEP;
@@ -412,27 +389,18 @@
return ret;
}
-asmlinkage void syscall_trace(void)
+asmlinkage int syscall_trace_enter(struct pt_regs *regs)
{
- if (!test_thread_flag(TIF_SYSCALL_TRACE))
- return;
+ int ret = 0;
- if (!(current->ptrace & PT_PTRACED))
- return;
+ if (test_thread_flag(TIF_SYSCALL_TRACE))
+ ret = tracehook_report_syscall_entry(regs);
- /* the 0x80 provides a way for the tracing parent to distinguish
- * between a syscall stop and SIGTRAP delivery
- */
- ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
- ? 0x80 : 0));
+ return ret;
+}
- /*
- * this isn't the same as continuing with a signal, but it will do
- * for normal use. strace only continues with a signal if the
- * stopping signal is not SIGTRAP. -brl
- */
- if (current->exit_code) {
- send_sig(current->exit_code, current, 1);
- current->exit_code = 0;
- }
+asmlinkage void syscall_trace_leave(struct pt_regs *regs)
+{
+ if (test_thread_flag(TIF_SYSCALL_TRACE))
+ tracehook_report_syscall_exit(regs, 0);
}
diff --git a/arch/blackfin/kernel/signal.c b/arch/blackfin/kernel/signal.c
index e0fd63e..e60990c 100644
--- a/arch/blackfin/kernel/signal.c
+++ b/arch/blackfin/kernel/signal.c
@@ -1,5 +1,5 @@
/*
- * Copyright 2004-2009 Analog Devices Inc.
+ * Copyright 2004-2010 Analog Devices Inc.
*
* Licensed under the GPL-2 or later
*/
@@ -206,16 +206,6 @@
regs->r1 = (unsigned long)(&frame->info);
regs->r2 = (unsigned long)(&frame->uc);
- /*
- * Clear the trace flag when entering the signal handler, but
- * notify any tracer that was single-stepping it. The tracer
- * may want to single-step inside the handler too.
- */
- if (regs->syscfg & TRACE_BITS) {
- regs->syscfg &= ~TRACE_BITS;
- ptrace_notify(SIGTRAP);
- }
-
return 0;
give_sigsegv:
@@ -315,6 +305,8 @@
* clear the TIF_RESTORE_SIGMASK flag */
if (test_thread_flag(TIF_RESTORE_SIGMASK))
clear_thread_flag(TIF_RESTORE_SIGMASK);
+
+ tracehook_signal_handler(signr, &info, &ka, regs, 1);
}
return;
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index 1fa414f..0df5b83 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -736,7 +736,8 @@
* this symbol need not be global anyways, so ...
*/
_sys_trace:
- pseudo_long_call _syscall_trace, p5;
+ r0 = sp;
+ pseudo_long_call _syscall_trace_enter, p5;
/* Execute the appropriate system call */
@@ -760,7 +761,8 @@
SP += 24;
[sp + PT_R0] = r0;
- pseudo_long_call _syscall_trace, p5;
+ r0 = sp;
+ pseudo_long_call _syscall_trace_leave, p5;
jump .Lresume_userspace;
ENDPROC(_sys_trace)