microblaze: Support ptrace syscall tracing.
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S
index c7353e7..acc1f05 100644
--- a/arch/microblaze/kernel/entry.S
+++ b/arch/microblaze/kernel/entry.S
@@ -308,38 +308,69 @@
swi r12, r1, PTO+PT_R0;
tovirt(r1,r1)
- la r15, r0, ret_from_trap-8
/* where the trap should return need -8 to adjust for rtsd r15, 8*/
/* Jump to the appropriate function for the system call number in r12
* (r12 is not preserved), or return an error if r12 is not valid. The LP
* register should point to the location where
* the called function should return. [note that MAKE_SYS_CALL uses label 1] */
- /* See if the system call number is valid. */
+
+ # Step into virtual mode.
+ set_vms;
+ addik r11, r0, 3f
+ rtid r11, 0
+ nop
+3:
+ add r11, r0, CURRENT_TASK /* Get current task ptr into r11 */
+ lwi r11, r11, TS_THREAD_INFO /* get thread info */
+ lwi r11, r11, TI_FLAGS /* get flags in thread info */
+ andi r11, r11, _TIF_WORK_SYSCALL_MASK
+ beqi r11, 4f
+
+ addik r3, r0, -ENOSYS
+ swi r3, r1, PTO + PT_R3
+ brlid r15, do_syscall_trace_enter
+ addik r5, r1, PTO + PT_R0
+
+ # do_syscall_trace_enter returns the new syscall nr.
+ addk r12, r0, r3
+ lwi r5, r1, PTO+PT_R5;
+ lwi r6, r1, PTO+PT_R6;
+ lwi r7, r1, PTO+PT_R7;
+ lwi r8, r1, PTO+PT_R8;
+ lwi r9, r1, PTO+PT_R9;
+ lwi r10, r1, PTO+PT_R10;
+4:
+/* Jump to the appropriate function for the system call number in r12
+ * (r12 is not preserved), or return an error if r12 is not valid.
+ * The LP register should point to the location where the called function
+ * should return. [note that MAKE_SYS_CALL uses label 1] */
+ /* See if the system call number is valid */
addi r11, r12, -__NR_syscalls;
- bgei r11,1f;
+ bgei r11,5f;
/* Figure out which function to use for this system call. */
/* Note Microblaze barrel shift is optional, so don't rely on it */
add r12, r12, r12; /* convert num -> ptr */
add r12, r12, r12;
/* Trac syscalls and stored them to r0_ram */
- lwi r3, r12, 0x400 + TOPHYS(r0_ram)
+ lwi r3, r12, 0x400 + r0_ram
addi r3, r3, 1
- swi r3, r12, 0x400 + TOPHYS(r0_ram)
+ swi r3, r12, 0x400 + r0_ram
- lwi r12, r12, TOPHYS(sys_call_table); /* Function ptr */
- /* Make the system call. to r12*/
- set_vms;
- rtid r12, 0;
- nop;
+ # Find and jump into the syscall handler.
+ lwi r12, r12, sys_call_table
+ /* where the trap should return need -8 to adjust for rtsd r15, 8 */
+ la r15, r0, ret_from_trap-8
+ bra r12
+
/* The syscall number is invalid, return an error. */
-1: VM_ON; /* RETURN() expects virtual mode*/
+5:
addi r3, r0, -ENOSYS;
rtsd r15,8; /* looks like a normal subroutine return */
or r0, r0, r0
-/* Entry point used to return from a syscall/trap. */
+/* Entry point used to return from a syscall/trap */
/* We re-enable BIP bit before state restore */
C_ENTRY(ret_from_trap):
set_bip; /* Ints masked for state restore*/
@@ -349,6 +380,23 @@
/* We're returning to user mode, so check for various conditions that
* trigger rescheduling. */
+ # FIXME: Restructure all these flag checks.
+ add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
+ lwi r11, r11, TS_THREAD_INFO; /* get thread info */
+ lwi r11, r11, TI_FLAGS; /* get flags in thread info */
+ andi r11, r11, _TIF_WORK_SYSCALL_MASK
+ beqi r11, 1f
+
+ swi r3, r1, PTO + PT_R3
+ swi r4, r1, PTO + PT_R4
+ brlid r15, do_syscall_trace_leave
+ addik r5, r1, PTO + PT_R0
+ lwi r3, r1, PTO + PT_R3
+ lwi r4, r1, PTO + PT_R4
+1:
+
+ /* We're returning to user mode, so check for various conditions that
+ * trigger rescheduling. */
/* Get current task ptr into r11 */
add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
lwi r11, r11, TS_THREAD_INFO; /* get thread info */
diff --git a/arch/microblaze/kernel/ptrace.c b/arch/microblaze/kernel/ptrace.c
index 53ff39a..4b3ac32 100644
--- a/arch/microblaze/kernel/ptrace.c
+++ b/arch/microblaze/kernel/ptrace.c
@@ -29,6 +29,10 @@
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/signal.h>
+#include <linux/elf.h>
+#include <linux/audit.h>
+#include <linux/seccomp.h>
+#include <linux/tracehook.h>
#include <linux/errno.h>
#include <asm/processor.h>
@@ -174,6 +178,64 @@
return rval;
}
+asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
+{
+ long ret = 0;
+
+ secure_computing(regs->r12);
+
+ if (test_thread_flag(TIF_SYSCALL_TRACE) &&
+ tracehook_report_syscall_entry(regs))
+ /*
+ * Tracing decided this syscall should not happen.
+ * We'll return a bogus call number to get an ENOSYS
+ * error, but leave the original number in regs->regs[0].
+ */
+ ret = -1L;
+
+ if (unlikely(current->audit_context))
+ audit_syscall_entry(EM_XILINX_MICROBLAZE, regs->r12,
+ regs->r5, regs->r6,
+ regs->r7, regs->r8);
+
+ return ret ?: regs->r12;
+}
+
+asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
+{
+ int step;
+
+ if (unlikely(current->audit_context))
+ audit_syscall_exit(AUDITSC_RESULT(regs->r3), regs->r3);
+
+ step = test_thread_flag(TIF_SINGLESTEP);
+ if (step || test_thread_flag(TIF_SYSCALL_TRACE))
+ tracehook_report_syscall_exit(regs, step);
+}
+
+#if 0
+static asmlinkage void syscall_trace(void)
+{
+ if (!test_thread_flag(TIF_SYSCALL_TRACE))
+ return;
+ if (!(current->ptrace & PT_PTRACED))
+ return;
+ /* 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));
+ /*
+ * 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;
+ }
+}
+#endif
+
void ptrace_disable(struct task_struct *child)
{
/* nothing to do */