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authorLinus Torvalds <torvalds@linux-foundation.org>2023-05-28 07:33:29 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2023-05-28 07:33:29 -0400
commitabbf7fa15b7c140da7893f9c910b4762ac99ae7a (patch)
tree030058753ed8383179e977840eec23f6f1947862
parentd8f14b84fefd8669cbcbe4fee3f61a44be904993 (diff)
parent2e4be0d011f21593c6b316806779ba1eba2cd7e0 (diff)
downloadlwn-abbf7fa15b7c140da7893f9c910b4762ac99ae7a.tar.gz
lwn-abbf7fa15b7c140da7893f9c910b4762ac99ae7a.zip
Merge tag 'objtool-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull unwinder fixes from Thomas Gleixner: "A set of unwinder and tooling fixes: - Ensure that the stack pointer on x86 is aligned again so that the unwinder does not read past the end of the stack - Discard .note.gnu.property section which has a pointlessly different alignment than the other note sections. That confuses tooling of all sorts including readelf, libbpf and pahole" * tag 'objtool-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/show_trace_log_lvl: Ensure stack pointer is aligned, again vmlinux.lds.h: Discard .note.gnu.property section
-rw-r--r--arch/x86/kernel/dumpstack.c7
-rw-r--r--include/asm-generic/vmlinux.lds.h9
2 files changed, 13 insertions, 3 deletions
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 0bf6779187dd..f18ca44c904b 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -195,7 +195,6 @@ static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
printk("%sCall Trace:\n", log_lvl);
unwind_start(&state, task, regs, stack);
- stack = stack ? : get_stack_pointer(task, regs);
regs = unwind_get_entry_regs(&state, &partial);
/*
@@ -214,9 +213,13 @@ static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
* - hardirq stack
* - entry stack
*/
- for ( ; stack; stack = PTR_ALIGN(stack_info.next_sp, sizeof(long))) {
+ for (stack = stack ?: get_stack_pointer(task, regs);
+ stack;
+ stack = stack_info.next_sp) {
const char *stack_name;
+ stack = PTR_ALIGN(stack, sizeof(long));
+
if (get_stack_info(stack, task, &stack_info, &visit_mask)) {
/*
* We weren't on a valid stack. It's possible that
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index d1f57e4868ed..cebdf1ca415d 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -891,9 +891,16 @@
/*
* Discard .note.GNU-stack, which is emitted as PROGBITS by the compiler.
* Otherwise, the type of .notes section would become PROGBITS instead of NOTES.
+ *
+ * Also, discard .note.gnu.property, otherwise it forces the notes section to
+ * be 8-byte aligned which causes alignment mismatches with the kernel's custom
+ * 4-byte aligned notes.
*/
#define NOTES \
- /DISCARD/ : { *(.note.GNU-stack) } \
+ /DISCARD/ : { \
+ *(.note.GNU-stack) \
+ *(.note.gnu.property) \
+ } \
.notes : AT(ADDR(.notes) - LOAD_OFFSET) { \
BOUNDED_SECTION_BY(.note.*, _notes) \
} NOTES_HEADERS \