Commit c8921d72e390 ("parisc: Fix and improve kernel stack unwinding")
broke booting of 64-bit kernels. On 64-bit kernels function pointers are
actually function descriptors which require dereferencing. In this patch
we instead declare functions in assembly code which are referenced from
C-code as external data pointers with the ENTRY() macro and thus can use
a simple external reference to the functions.
Signed-off-by: Helge Deller <deller@xxxxxx>
Fixes: c8921d72e390 ("parisc: Fix and improve kernel stack unwinding")
diff --git a/arch/parisc/include/asm/linkage.h b/arch/parisc/include/asm/linkage.h
index 49f6f3d772cc..cd6fe4febead 100644
--- a/arch/parisc/include/asm/linkage.h
+++ b/arch/parisc/include/asm/linkage.h
@@ -22,15 +22,6 @@
name: ASM_NL\
.export name
-#ifdef CONFIG_64BIT
-#define ENDPROC(name) \
- END(name)
-#else
-#define ENDPROC(name) \
- .type name, @function !\
- END(name)
-#endif
-
#define ENTRY_CFI(name, ...) \
ENTRY(name) ASM_NL\
.proc ASM_NL\
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
index e170365941f8..242c5ab65611 100644
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -777,7 +777,7 @@ END(fault_vector_11)
* copy_thread moved args into task save area.
*/
-ENTRY_CFI(ret_from_kernel_thread)
+ENTRY(ret_from_kernel_thread)
/* Call schedule_tail first though */
BL schedule_tail, %r2
nop
@@ -792,7 +792,7 @@ ENTRY_CFI(ret_from_kernel_thread)
copy %r31, %r2
b finish_child_return
nop
-ENDPROC_CFI(ret_from_kernel_thread)
+END(ret_from_kernel_thread)
/*
@@ -816,9 +816,8 @@ ENTRY_CFI(_switch_to)
LDREG TASK_THREAD_INFO(%r25), %r25
bv %r0(%r2)
mtctl %r25,%cr30
-ENDPROC_CFI(_switch_to)
-ENTRY_CFI(_switch_to_ret)
+ENTRY(_switch_to_ret)
mtctl %r0, %cr0 /* Needed for single stepping */
callee_rest
callee_rest_float
@@ -826,7 +825,7 @@ ENTRY_CFI(_switch_to_ret)
LDREG -RP_OFFSET(%r30), %r2
bv %r0(%r2)
copy %r26, %r28
-ENDPROC_CFI(_switch_to_ret)
+ENDPROC_CFI(_switch_to)
/*
* Common rfi return path for interruptions, kernel execve, and
@@ -887,14 +886,12 @@ ENTRY_CFI(syscall_exit_rfi)
STREG %r19,PT_SR5(%r16)
STREG %r19,PT_SR6(%r16)
STREG %r19,PT_SR7(%r16)
-ENDPROC_CFI(syscall_exit_rfi)
-ENTRY_CFI(intr_return)
+ENTRY(intr_return)
/* check for reschedule */
mfctl %cr30,%r1
LDREG TI_FLAGS(%r1),%r19 /* sched.h: TIF_NEED_RESCHED */
bb,<,n %r19,31-TIF_NEED_RESCHED,intr_do_resched /* forward */
-ENDPROC_CFI(intr_return)
.import do_notify_resume,code
intr_check_sig:
@@ -1050,6 +1047,7 @@ intr_extint:
b do_cpu_irq_mask
ldo R%intr_return(%r2), %r2 /* return to intr_return, not here */
+ENDPROC_CFI(syscall_exit_rfi)
/* Generic interruptions (illegal insn, unaligned, page fault, etc) */
@@ -1751,7 +1749,7 @@ fork_like fork
fork_like vfork
/* Set the return value for the child */
-ENTRY_CFI(child_return)
+ENTRY(child_return)
BL schedule_tail, %r2
nop
finish_child_return:
@@ -1763,7 +1761,7 @@ finish_child_return:
reg_restore %r1
b syscall_exit
copy %r0,%r28
-ENDPROC_CFI(child_return)
+END(child_return)
ENTRY_CFI(sys_rt_sigreturn_wrapper)
LDREG TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r26
@@ -1795,7 +1793,7 @@ ENTRY_CFI(sys_rt_sigreturn_wrapper)
LDREG PT_GR28(%r1),%r28 /* reload original r28 for syscall_exit */
ENDPROC_CFI(sys_rt_sigreturn_wrapper)
-ENTRY_CFI(syscall_exit)
+ENTRY(syscall_exit)
/* NOTE: Not all syscalls exit this way. rt_sigreturn will exit
* via syscall_exit_rfi if the signal was received while the process
* was running.
@@ -1994,15 +1992,13 @@ syscall_do_resched:
#else
nop
#endif
-ENDPROC_CFI(syscall_exit)
+END(syscall_exit)
#ifdef CONFIG_FUNCTION_TRACER
.import ftrace_function_trampoline,code
.align L1_CACHE_BYTES
- .globl mcount
- .type mcount, @function
ENTRY_CFI(mcount, caller)
_mcount:
.export _mcount,data
@@ -2031,8 +2027,6 @@ ENDPROC_CFI(mcount)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
.align 8
- .globl return_to_handler
- .type return_to_handler, @function
ENTRY_CFI(return_to_handler, caller,frame=FRAME_SIZE)
.export parisc_return_to_handler,data
parisc_return_to_handler:
@@ -2082,6 +2076,7 @@ ENDPROC_CFI(return_to_handler)
/* void call_on_stack(unsigned long param1, void *func,
unsigned long new_stack) */
ENTRY_CFI(call_on_stack, FRAME=2*FRAME_SIZE,CALLS,SAVE_RP,SAVE_SP)
+ENTRY(_call_on_stack)
copy %sp, %r1
/* Regarding the HPPA calling conventions for function pointers,
diff --git a/arch/parisc/kernel/unwind.c b/arch/parisc/kernel/unwind.c
index 5578a325a730..f329b466e68f 100644
--- a/arch/parisc/kernel/unwind.c
+++ b/arch/parisc/kernel/unwind.c
@@ -209,6 +209,8 @@ static int unwind_special(struct unwind_frame_info *info, unsigned long pc, int
* We have to use void * instead of a function pointer, because
* function pointers aren't a pointer to the function on 64-bit.
* Make them const so the compiler knows they live in .text
+ * Note: We could use dereference_kernel_function_descriptor()
+ * instead but we want to keep it simple here.
*/
extern void * const handle_interruption;
extern void * const ret_from_kernel_thread;
@@ -216,7 +218,7 @@ static int unwind_special(struct unwind_frame_info *info, unsigned long pc, int
extern void * const intr_return;
extern void * const _switch_to_ret;
#ifdef CONFIG_IRQSTACKS
- extern void * const call_on_stack;
+ extern void * const _call_on_stack;
#endif /* CONFIG_IRQSTACKS */
if (pc == (unsigned long) &handle_interruption) {
@@ -251,7 +253,7 @@ static int unwind_special(struct unwind_frame_info *info, unsigned long pc, int
}
#ifdef CONFIG_IRQSTACKS
- if (pc == (unsigned long) &call_on_stack) {
+ if (pc == (unsigned long) &_call_on_stack) {
info->prev_sp = *(unsigned long *)(info->sp - FRAME_SIZE - REG_SZ);
info->prev_ip = *(unsigned long *)(info->sp - FRAME_SIZE - RP_OFFSET);
return 1;
