[v4,22/39] unwind_user/sframe: Wire up unwind_user to sframe

Commit Message

Josh Poimboeuf Jan. 22, 2025, 2:31 a.m. UTC

Now that the sframe infrastructure is fully in place, make it work by
hooking it up to the unwind_user interface.

Signed-off-by: Josh Poimboeuf <[e-mail]>
---
 arch/Kconfig                      |  1 +
 include/linux/unwind_user_types.h |  1 +
 kernel/unwind/user.c              | 22 +++++++++++++++++++---
 3 files changed, 21 insertions(+), 3 deletions(-)

Patch

diff --git a/arch/Kconfig b/arch/Kconfig
index 23edd0e4e16a..12a3b73cbe66 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -448,6 +448,7 @@  config HAVE_UNWIND_USER_COMPAT_FP
 
 config HAVE_UNWIND_USER_SFRAME
 	bool
+	select UNWIND_USER
 
 config AS_SFRAME
 	def_bool $(as-instr,.cfi_sections .sframe\n.cfi_startproc\n.cfi_endproc)
diff --git a/include/linux/unwind_user_types.h b/include/linux/unwind_user_types.h
index 3ec4a097a3dd..5558558948b7 100644
--- a/include/linux/unwind_user_types.h
+++ b/include/linux/unwind_user_types.h
@@ -9,6 +9,7 @@  enum unwind_user_type {
 	UNWIND_USER_TYPE_NONE,
 	UNWIND_USER_TYPE_FP,
 	UNWIND_USER_TYPE_COMPAT_FP,
+	UNWIND_USER_TYPE_SFRAME,
 };
 
 struct unwind_stacktrace {
diff --git a/kernel/unwind/user.c b/kernel/unwind/user.c
index 92963f129c6a..fc0c75da81f6 100644
--- a/kernel/unwind/user.c
+++ b/kernel/unwind/user.c
@@ -6,6 +6,7 @@ 
 #include <linux/sched.h>
 #include <linux/sched/task_stack.h>
 #include <linux/unwind_user.h>
+#include <linux/sframe.h>
 #include <linux/uaccess.h>
 #include <asm/unwind_user.h>
 
@@ -29,6 +30,12 @@  static inline bool compat_state(struct unwind_user_state *state)
 	       state->type == UNWIND_USER_TYPE_COMPAT_FP;
 }
 
+static inline bool sframe_state(struct unwind_user_state *state)
+{
+	return IS_ENABLED(CONFIG_HAVE_UNWIND_USER_SFRAME) &&
+	       state->type == UNWIND_USER_TYPE_SFRAME;
+}
+
 #define UNWIND_GET_USER_LONG(to, from, state)				\
 ({									\
 	int __ret;							\
@@ -48,12 +55,19 @@  int unwind_user_next(struct unwind_user_state *state)
 	if (state->done)
 		return -EINVAL;
 
-	if (compat_state(state))
+	if (compat_state(state)) {
 		frame = &compat_fp_frame;
-	else if (fp_state(state))
+	} else if (sframe_state(state)) {
+		if (sframe_find(state->ip, frame)) {
+			if (!IS_ENABLED(CONFIG_HAVE_UNWIND_USER_FP))
+				goto the_end;
+			frame = &fp_frame;
+		}
+	} else if (fp_state(state)) {
 		frame = &fp_frame;
-	else
+	} else {
 		goto the_end;
+	}
 
 	cfa = (frame->use_fp ? state->fp : state->sp) + frame->cfa_off;
 
@@ -94,6 +108,8 @@  int unwind_user_start(struct unwind_user_state *state)
 
 	if (IS_ENABLED(CONFIG_HAVE_UNWIND_USER_COMPAT_FP) && in_compat_mode(regs))
 		state->type = UNWIND_USER_TYPE_COMPAT_FP;
+	else if (current_has_sframe())
+		state->type = UNWIND_USER_TYPE_SFRAME;
 	else if (IS_ENABLED(CONFIG_HAVE_UNWIND_USER_FP))
 		state->type = UNWIND_USER_TYPE_FP;
 	else