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parisc: Fix boot failure of 64-bit kernel

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Commit c8921d72e3 ("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@gmx.de>
Fixes: c8921d72e3 ("parisc: Fix and improve kernel stack unwinding")
This commit is contained in:
Helge Deller
2018-08-21 14:31:32 +02:00
parent 9e0d5c451f
commit 8801ccb9fa
3 changed files with 15 additions and 27 deletions
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6
arch/parisc/kernel/unwind.c
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@@ -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;