Some assembly symbols contain code that might be executed with an unspecified stack state (e.g. invalid stack pointer,no stackframe, ...). Annotate those symbol with UNWIND_HINT_EMPTY to let objtool be aware of them. When taking an exception/interrupt, add UNWIND_HINT_REGS to indicate from which point the pt_regs is on stack. Whether returning to userland or creating a new task, sp is pointing to a pt_regs frame, add UNWIND_HINT_REGS after that. Co-developed-by: Jinyang He <hejinyang@xxxxxxxxxxx> Signed-off-by: Jinyang He <hejinyang@xxxxxxxxxxx> Signed-off-by: Youling Tang <tangyouling@xxxxxxxxxxx> --- arch/loongarch/include/asm/stackframe.h | 3 +++ arch/loongarch/kernel/entry.S | 2 ++ arch/loongarch/kernel/head.S | 1 + arch/loongarch/kernel/relocate_kernel.S | 5 +++++ 4 files changed, 11 insertions(+) diff --git a/arch/loongarch/include/asm/stackframe.h b/arch/loongarch/include/asm/stackframe.h index 7df80e6ae9d2..ab16f2d10257 100644 --- a/arch/loongarch/include/asm/stackframe.h +++ b/arch/loongarch/include/asm/stackframe.h @@ -13,6 +13,7 @@ #include <asm/asm-offsets.h> #include <asm/loongarch.h> #include <asm/thread_info.h> +#include <asm/unwind_hints.h> /* Make the addition of cfi info a little easier. */ .macro cfi_rel_offset reg offset=0 docfi=0 @@ -158,6 +159,7 @@ cfi_st u0, PT_R21, \docfi csrrd u0, PERCPU_BASE_KS 9: + UNWIND_HINT_REGS .endm .macro SAVE_ALL docfi=0 @@ -215,6 +217,7 @@ .macro RESTORE_SP_AND_RET docfi=0 cfi_ld sp, PT_R3, \docfi + UNWIND_HINT_FUNC ertn .endm diff --git a/arch/loongarch/kernel/entry.S b/arch/loongarch/kernel/entry.S index d737e3cf42d3..458d4e8e126f 100644 --- a/arch/loongarch/kernel/entry.S +++ b/arch/loongarch/kernel/entry.S @@ -70,6 +70,7 @@ SYM_FUNC_END(handle_syscall) _ASM_NOKPROBE(handle_syscall) SYM_CODE_START(ret_from_fork) + UNWIND_HINT_REGS bl schedule_tail # a0 = struct task_struct *prev move a0, sp bl syscall_exit_to_user_mode @@ -79,6 +80,7 @@ SYM_CODE_START(ret_from_fork) SYM_CODE_END(ret_from_fork) SYM_CODE_START(ret_from_kernel_thread) + UNWIND_HINT_REGS bl schedule_tail # a0 = struct task_struct *prev move a0, s1 jirl ra, s0, 0 diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S index aa64b179744f..73e5ec0006bb 100644 --- a/arch/loongarch/kernel/head.S +++ b/arch/loongarch/kernel/head.S @@ -43,6 +43,7 @@ SYM_DATA(kernel_offset, .long kernel_offset - _text); .align 12 SYM_CODE_START(kernel_entry) # kernel entry point + UNWIND_HINT_EMPTY /* Config direct window and set PG */ li.d t0, CSR_DMW0_INIT # UC, PLV0, 0x8000 xxxx xxxx xxxx diff --git a/arch/loongarch/kernel/relocate_kernel.S b/arch/loongarch/kernel/relocate_kernel.S index d13252553a7c..d0123fa2b511 100644 --- a/arch/loongarch/kernel/relocate_kernel.S +++ b/arch/loongarch/kernel/relocate_kernel.S @@ -13,8 +13,11 @@ #include <asm/loongarch.h> #include <asm/stackframe.h> #include <asm/addrspace.h> +#include <asm/unwind_hints.h> SYM_CODE_START(relocate_new_kernel) + UNWIND_HINT_EMPTY + /* * a0: EFI boot flag for the new kernel * a1: Command line pointer for the new kernel @@ -91,6 +94,8 @@ SYM_CODE_END(relocate_new_kernel) * then start at the entry point from LOONGARCH_IOCSR_MBUF0. */ SYM_CODE_START(kexec_smp_wait) + UNWIND_HINT_EMPTY + 1: li.w t0, 0x100 /* wait for init loop */ 2: addi.w t0, t0, -1 /* limit mailbox access */ bnez t0, 2b -- 2.39.2
