Commit 8801ccb9 authored by Helge Deller's avatar Helge Deller
Browse files

parisc: Fix boot failure of 64-bit kernel 



Commit c8921d72 ("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: default avatarHelge Deller <deller@gmx.de>
Fixes: c8921d72 ("parisc: Fix and improve kernel stack unwinding")
parent 9e0d5c45

arch/parisc/include/asm/linkage.h

+0 −9
Original line number Diff line number Diff line
@@ -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\

arch/parisc/kernel/entry.S

+11 −16
Original line number Diff line number Diff line
@@ -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,

arch/parisc/kernel/unwind.c

+4 −2
Original line number Diff line number Diff line
@@ -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;

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