[PATCH v5 6/8] arm64/module, sframe: Add sframe support for modules

Dylan Hatch
2026-04-28T18:37:40Z

Add sframe table to mod_arch_specific and support sframe PC lookups when
an .sframe section can be found on incoming modules.

Signed-off-by: Weinan Liu <wnliu@google.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Dylan Hatch <dylanbhatch@google.com>
---
arch/arm64/include/asm/module.h | 6 +++++
arch/arm64/kernel/module.c | 8 +++++++
include/linux/sframe.h | 2 ++
kernel/unwind/sframe.c | 40 +++++++++++++++++++++++++++++++--
4 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/module.h b/arch/arm64/include/asm/module.h
index fb9b88eebeb1..07f309c51eee 100644
--- a/arch/arm64/include/asm/module.h
+++ b/arch/arm64/include/asm/module.h
@@ -6,6 +6,7 @@
#define __ASM_MODULE_H

#include <asm-generic/module.h>
+#include <linux/sframe.h>

struct mod_plt_sec {
int plt_shndx;
@@ -17,6 +18,11 @@ struct mod_arch_specific {
struct mod_plt_sec core;
struct mod_plt_sec init;

+#ifdef CONFIG_HAVE_UNWIND_KERNEL_SFRAME
+ struct sframe_section sframe_sec;
+ bool sframe_init;
+#endif
+
/* for CONFIG_DYNAMIC_FTRACE */
struct plt_entry *ftrace_trampolines;
struct plt_entry *init_ftrace_trampolines;
diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index 24adb581af0e..427f187e9531 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -18,6 +18,7 @@
#include <linux/moduleloader.h>
#include <linux/random.h>
#include <linux/scs.h>
+#include <linux/sframe.h>

#include <asm/alternative.h>
#include <asm/insn.h>
@@ -515,5 +516,12 @@ int module_finalize(const Elf_Ehdr *hdr,
}
}

+ s = find_section(hdr, sechdrs, ".sframe");
+ if (s) {
+ struct module_memory *t = &me->mem[MOD_TEXT];
+
+ sframe_module_init(me, (void *)s->sh_addr, s->sh_size,
+ t->base, t->size);
+ }
return module_init_ftrace_plt(hdr, sechdrs, me);
}
diff --git a/include/linux/sframe.h b/include/linux/sframe.h
index 8ae31ed36226..27f5a66190af 100644
--- a/include/linux/sframe.h
+++ b/include/linux/sframe.h
@@ -81,6 +81,8 @@ extern int sframe_find_kernel(unsigned long ip, struct unwind_frame *frame);
#else

static inline void __init init_sframe_table(void) {}
+static inline void sframe_module_init(struct module *mod, void *sframe, size_t sframe_size,
+ void *text, size_t text_size) {}

#endif /* CONFIG_HAVE_UNWIND_KERNEL_SFRAME */

diff --git a/kernel/unwind/sframe.c b/kernel/unwind/sframe.c
index dcf4deb378dc..70001c8e586d 100644
--- a/kernel/unwind/sframe.c
+++ b/kernel/unwind/sframe.c
@@ -980,10 +980,27 @@ void sframe_free_mm(struct mm_struct *mm)

int sframe_find_kernel(unsigned long ip, struct unwind_frame *frame)
{
- if (!frame || !sframe_init)
+ struct sframe_section *sec;
+
+ if (!frame)
return -EINVAL;

- return __sframe_find(&kernel_sfsec, ip, frame);
+ if (is_ksym_addr(ip)) {
+ if (!sframe_init)
+ return -EINVAL;
+
+ sec = &kernel_sfsec;
+ } else {
+ struct module *mod;
+
+ mod = __module_address(ip);
+ if (!mod || !mod->arch.sframe_init)
+ return -EINVAL;
+
+ sec = &mod->arch.sframe_sec;
+ }
+
+ return __sframe_find(sec, ip, frame);
}

void __init init_sframe_table(void)
@@ -1000,4 +1017,23 @@ void __init init_sframe_table(void)
sframe_init = true;
}

+void sframe_module_init(struct module *mod, void *sframe, size_t sframe_size,
+ void *text, size_t text_size)
+{
+ struct sframe_section sec;
+
+ memset(&sec, 0, sizeof(sec));
+ sec.sec_type = SFRAME_KERNEL;
+ sec.sframe_start = (unsigned long)sframe;
+ sec.sframe_end = (unsigned long)sframe + sframe_size;
+ sec.text_start = (unsigned long)text;
+ sec.text_end = (unsigned long)text + text_size;
+
+ if (WARN_ON(sframe_read_header(&sec)))
+ return;
+
+ mod->arch.sframe_sec = sec;
+ mod->arch.sframe_init = true;
+}
+
#endif /* CONFIG_HAVE_UNWIND_KERNEL_SFRAME */
--
2.54.0.545.g6539524ca2-goog