From 882a2a724ee964c1ebe7268a91d5c8c8ddc796bf Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Thu, 15 Feb 2024 13:51:45 -0800 Subject: parisc: Fix stack unwinder Debugging shows a large number of unaligned access traps in the unwinder code. Code analysis reveals a number of issues with this code: - handle_interruption is passed twice through dereference_kernel_function_descriptor() - ret_from_kernel_thread, syscall_exit, intr_return, _switch_to_ret, and _call_on_stack are passed through dereference_kernel_function_descriptor() even though they are not declared as function pointers. To fix the problems, drop one of the calls to dereference_kernel_function_descriptor() for handle_interruption, and compare the other pointers directly. Fixes: 6414b30b39f9 ("parisc: unwind: Avoid missing prototype warning for handle_interruption()") Fixes: 8e0ba125c2bf ("parisc/unwind: fix unwinder when CONFIG_64BIT is enabled") Cc: Helge Deller Cc: Sven Schnelle Cc: John David Anglin Cc: Charlie Jenkins Cc: David Laight Signed-off-by: Guenter Roeck Signed-off-by: Helge Deller --- arch/parisc/kernel/unwind.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) (limited to 'arch') diff --git a/arch/parisc/kernel/unwind.c b/arch/parisc/kernel/unwind.c index 27ae40a443b8..f7e0fee5ee55 100644 --- a/arch/parisc/kernel/unwind.c +++ b/arch/parisc/kernel/unwind.c @@ -228,10 +228,8 @@ static int unwind_special(struct unwind_frame_info *info, unsigned long pc, int #ifdef CONFIG_IRQSTACKS extern void * const _call_on_stack; #endif /* CONFIG_IRQSTACKS */ - void *ptr; - ptr = dereference_kernel_function_descriptor(&handle_interruption); - if (pc_is_kernel_fn(pc, ptr)) { + if (pc_is_kernel_fn(pc, handle_interruption)) { struct pt_regs *regs = (struct pt_regs *)(info->sp - frame_size - PT_SZ_ALGN); dbg("Unwinding through handle_interruption()\n"); info->prev_sp = regs->gr[30]; @@ -239,13 +237,13 @@ static int unwind_special(struct unwind_frame_info *info, unsigned long pc, int return 1; } - if (pc_is_kernel_fn(pc, ret_from_kernel_thread) || - pc_is_kernel_fn(pc, syscall_exit)) { + if (pc == (unsigned long)&ret_from_kernel_thread || + pc == (unsigned long)&syscall_exit) { info->prev_sp = info->prev_ip = 0; return 1; } - if (pc_is_kernel_fn(pc, intr_return)) { + if (pc == (unsigned long)&intr_return) { struct pt_regs *regs; dbg("Found intr_return()\n"); @@ -257,14 +255,14 @@ static int unwind_special(struct unwind_frame_info *info, unsigned long pc, int } if (pc_is_kernel_fn(pc, _switch_to) || - pc_is_kernel_fn(pc, _switch_to_ret)) { + pc == (unsigned long)&_switch_to_ret) { info->prev_sp = info->sp - CALLEE_SAVE_FRAME_SIZE; info->prev_ip = *(unsigned long *)(info->prev_sp - RP_OFFSET); return 1; } #ifdef CONFIG_IRQSTACKS - if (pc_is_kernel_fn(pc, _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; -- cgit