Merge tag 'riscv-for-linus-6.2-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:

 - Support for the T-Head PMU via the perf subsystem

 - ftrace support for rv32

 - Support for non-volatile memory devices

 - Various fixes and cleanups

* tag 'riscv-for-linus-6.2-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (52 commits)
  Documentation: RISC-V: patch-acceptance: s/implementor/implementer
  Documentation: RISC-V: Mention the UEFI Standards
  Documentation: RISC-V: Allow patches for non-standard behavior
  Documentation: RISC-V: Fix a typo in patch-acceptance
  riscv: Fixup compile error with !MMU
  riscv: Fix P4D_SHIFT definition for 3-level page table mode
  riscv: Apply a static assert to riscv_isa_ext_id
  RISC-V: Add some comments about the shadow and overflow stacks
  RISC-V: Align the shadow stack
  RISC-V: Ensure Zicbom has a valid block size
  RISC-V: Introduce riscv_isa_extension_check
  RISC-V: Improve use of isa2hwcap[]
  riscv: Don't duplicate _ALTERNATIVE_CFG* macros
  riscv: alternatives: Drop the underscores from the assembly macro names
  riscv: alternatives: Don't name unused macro parameters
  riscv: Don't duplicate __ALTERNATIVE_CFG in __ALTERNATIVE_CFG_2
  riscv: mm: call best_map_size many times during linear-mapping
  riscv: Move cast inside kernel_mapping_[pv]a_to_[vp]a
  riscv: Fix crash during early errata patching
  riscv: boot: add zstd support
  ...

1 files changed, 10 insertions, 1 deletions

diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
index 08d11a53f39e..75c8dd64fc48 100644
--- a/arch/riscv/kernel/stacktrace.c
+++ b/arch/riscv/kernel/stacktrace.c
@@ -16,6 +16,8 @@
 
 #ifdef CONFIG_FRAME_POINTER
 
+extern asmlinkage void ret_from_exception(void);
+
 void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
 			     bool (*fn)(void *, unsigned long), void *arg)
 {
@@ -58,7 +60,14 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
 		} else {
 			fp = frame->fp;
 			pc = ftrace_graph_ret_addr(current, NULL, frame->ra,
-						   (unsigned long *)(fp - 8));
+						   &frame->ra);
+			if (pc == (unsigned long)ret_from_exception) {
+				if (unlikely(!__kernel_text_address(pc) || !fn(arg, pc)))
+					break;
+
+				pc = ((struct pt_regs *)sp)->epc;
+				fp = ((struct pt_regs *)sp)->s0;
+			}
 		}
 
 	}