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author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-05-28 07:33:29 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-05-28 07:33:29 -0400 |
commit | abbf7fa15b7c140da7893f9c910b4762ac99ae7a (patch) | |
tree | 030058753ed8383179e977840eec23f6f1947862 | |
parent | d8f14b84fefd8669cbcbe4fee3f61a44be904993 (diff) | |
parent | 2e4be0d011f21593c6b316806779ba1eba2cd7e0 (diff) | |
download | lwn-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.c | 7 | ||||
-rw-r--r-- | include/asm-generic/vmlinux.lds.h | 9 |
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 \ |