csky: Fixup add zero_fp fixup perf backtrace panic

We need set fp zero to let backtrace know the end. The patch fixup perf
callchain panic problem, because backtrace didn't know what is the end
of fp.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reported-by: Mao Han <han_mao@c-sky.com>

diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S
index a7e84ccccbd8ee47ff0cdba63b4f5a6f4c647fed..564dab2fabaa400bcbe759d5127178856349095a 100644 (file)
--- a/arch/csky/kernel/entry.S
+++ b/arch/csky/kernel/entry.S
@@ -17,6 +17,12 @@
 #define PTE_INDX_SHIFT  10
 #define _PGDIR_SHIFT    22
 
+.macro zero_fp
+#ifdef CONFIG_STACKTRACE
+       movi    r8, 0
+#endif
+.endm
+
 .macro tlbop_begin name, val0, val1, val2
 ENTRY(csky_\name)
        mtcr    a3, ss2
@@ -96,6 +102,7 @@ ENTRY(csky_\name)
        SAVE_ALL 0
 .endm
 .macro tlbop_end is_write
+       zero_fp
        RD_MEH  a2
        psrset  ee, ie
        mov     a0, sp
@@ -120,6 +127,7 @@ tlbop_end 1
 
 ENTRY(csky_systemcall)
        SAVE_ALL TRAP0_SIZE
+       zero_fp
 
        psrset  ee, ie
 
@@ -136,9 +144,9 @@ ENTRY(csky_systemcall)
        mov     r9, sp
        bmaski  r10, THREAD_SHIFT
        andn    r9, r10
-       ldw     r8, (r9, TINFO_FLAGS)
-       ANDI_R3 r8, (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT | _TIF_SYSCALL_AUDIT)
-       cmpnei  r8, 0
+       ldw     r12, (r9, TINFO_FLAGS)
+       ANDI_R3 r12, (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT | _TIF_SYSCALL_AUDIT)
+       cmpnei  r12, 0
        bt      csky_syscall_trace
 #if defined(__CSKYABIV2__)
        subi    sp, 8
@@ -180,7 +188,7 @@ csky_syscall_trace:
 
 ENTRY(ret_from_kernel_thread)
        jbsr    schedule_tail
-       mov     a0, r8
+       mov     a0, r10
        jsr     r9
        jbsr    ret_from_exception
 
@@ -189,9 +197,9 @@ ENTRY(ret_from_fork)
        mov     r9, sp
        bmaski  r10, THREAD_SHIFT
        andn    r9, r10
-       ldw     r8, (r9, TINFO_FLAGS)
-       ANDI_R3 r8, (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT | _TIF_SYSCALL_AUDIT)
-       cmpnei  r8, 0
+       ldw     r12, (r9, TINFO_FLAGS)
+       ANDI_R3 r12, (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT | _TIF_SYSCALL_AUDIT)
+       cmpnei  r12, 0
        bf      ret_from_exception
        mov     a0, sp                  /* sp = pt_regs pointer */
        jbsr    syscall_trace_exit
@@ -209,9 +217,9 @@ ret_from_exception:
        bmaski  r10, THREAD_SHIFT
        andn    r9, r10
 
-       ldw     r8, (r9, TINFO_FLAGS)
-       andi    r8, (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED)
-       cmpnei  r8, 0
+       ldw     r12, (r9, TINFO_FLAGS)
+       andi    r12, (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED)
+       cmpnei  r12, 0
        bt      exit_work
 1:
        RESTORE_ALL
@@ -220,11 +228,11 @@ exit_work:
        lrw     syscallid, ret_from_exception
        mov     lr, syscallid
 
-       btsti   r8, TIF_NEED_RESCHED
+       btsti   r12, TIF_NEED_RESCHED
        bt      work_resched
 
        mov     a0, sp
-       mov     a1, r8
+       mov     a1, r12
        jmpi    do_notify_resume
 
 work_resched:
@@ -232,6 +240,7 @@ work_resched:
 
 ENTRY(csky_trap)
        SAVE_ALL 0
+       zero_fp
        psrset  ee
        mov     a0, sp                 /* Push Stack pointer arg */
        jbsr    trap_c                 /* Call C-level trap handler */
@@ -265,6 +274,7 @@ ENTRY(csky_get_tls)
 
 ENTRY(csky_irq)
        SAVE_ALL 0
+       zero_fp
        psrset  ee
 
 #ifdef CONFIG_PREEMPT
@@ -276,21 +286,21 @@ ENTRY(csky_irq)
         * Get task_struct->stack.preempt_count for current,
         * and increase 1.
         */
-       ldw     r8, (r9, TINFO_PREEMPT)
-       addi    r8, 1
-       stw     r8, (r9, TINFO_PREEMPT)
+       ldw     r12, (r9, TINFO_PREEMPT)
+       addi    r12, 1
+       stw     r12, (r9, TINFO_PREEMPT)
 #endif
 
        mov     a0, sp
        jbsr    csky_do_IRQ
 
 #ifdef CONFIG_PREEMPT
-       subi    r8, 1
-       stw     r8, (r9, TINFO_PREEMPT)
-       cmpnei  r8, 0
+       subi    r12, 1
+       stw     r12, (r9, TINFO_PREEMPT)
+       cmpnei  r12, 0
        bt      2f
-       ldw     r8, (r9, TINFO_FLAGS)
-       btsti   r8, TIF_NEED_RESCHED
+       ldw     r12, (r9, TINFO_FLAGS)
+       btsti   r12, TIF_NEED_RESCHED
        bf      2f
 1:
        jbsr    preempt_schedule_irq    /* irq en/disable is done inside */

diff --git a/arch/csky/kernel/process.c b/arch/csky/kernel/process.c
index e555740c0be5768d001c81fe8ff91e98e71e0e4b..f320d9248a225fe31941129ccd2b4225c47f36d1 100644 (file)
--- a/arch/csky/kernel/process.c
+++ b/arch/csky/kernel/process.c
@@ -55,7 +55,7 @@ int copy_thread(unsigned long clone_flags,
        if (unlikely(p->flags & PF_KTHREAD)) {
                memset(childregs, 0, sizeof(struct pt_regs));
                childstack->r15 = (unsigned long) ret_from_kernel_thread;
-               childstack->r8 = kthread_arg;
+               childstack->r10 = kthread_arg;
                childstack->r9 = usp;
                childregs->sr = mfcr("psr");
        } else {