[next-20251022] Kernel Boot Warnings at arch/powerpc/kernel/trace/ftrace.c:234

[Josh Poimboeuf]

On Wed, Oct 29, 2025 at 11:42:54PM +0530, Hari Bathini wrote:
> Hi Petr,
> On 23/10/25 2:42 pm, Petr Mladek wrote:
> > On Wed 2025-10-22 19:56:45, Venkat Rao Bagalkote wrote:
> > > 
> > > On 22/10/25 6:36 pm, Petr Mladek wrote:
> > > > On Wed 2025-10-22 17:36:18, Venkat Rao Bagalkote wrote:
> > > > > On 22/10/25 1:52 pm, Venkat Rao Bagalkote wrote:
> > > > > > Greetings!!!
> > > > > > 
> > > > > > 
> > > > > > IBM CI has reported kernel boot warnings with next-20251022 kernel. I
> > > > > > see there are couple of warnings hit and eventually system boots to
> > > > > > emergency mode.
> > > > > > 
> > > > > > 
> > > > > With the identified first bad commit, is casuing the kernel to boot to
> > > > > emergency mode. I reverted the bad commit and built the kernel, then kernel
> > > > > is booting fine, but with boot warnings.
> > > > I guess that it is the same problem which should get fixed by the patch
> > > > https://lore.kernel.org/r/e52ee3edf32874da645a9e037a7d77c69893a22a.1760982784.git.jpoimboe@kernel.org
> > > 
> > > 
> > > Thank you Petr, for pointing to the fix patch. It fixes the kernel booting
> > > to emergency mode.
> > 
> > Great.
> > 
> > > But boot warning still persists.
> > 
> > I looks like another problem. I would expect that it is in
> > the ftrace code, either in the generic or arch-specific part.
> Yeah. This is part of arch-specific code that does init of ftrace
> out line stubs. The problem seems to be since commit 1ba9f8979426
> ("vmlinux.lds: Unify TEXT_MAIN, DATA_MAIN, and related macros").
> Before this commit, .text.startup section was featured in INIT_TEXT
> but now it seems to feature in TEXT. Is this change right/intentional?
> If yes, I can post a fix patch in ftrace arch-specific code accordingly.

Ah, I wasn't aware of .text.startup.  Apparently it's used by KASAN,
KCSCAN and GCOV for a significant amount of constructor code, which is
only called during boot.  So we should try to keep it in .init.text.

Venkat, does this fix it?

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 5facbc9946344..9de1d900fa154 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -88,13 +88,29 @@
 
 /*
  * Support -ffunction-sections by matching .text and .text.*,
- * but exclude '.text..*'.
+ * but exclude '.text..*', .text.startup[.*], and .text.exit[.*].
  *
- * Special .text.* sections that are typically grouped separately, such as
+ * .text.startup and .text.startup.* are matched later by INIT_TEXT.
+ * .text.exit and .text.exit.* are matched later by EXIT_TEXT.
+ *
+ * Other .text.* sections that are typically grouped separately, such as
  * .text.unlikely or .text.hot, must be matched explicitly before using
  * TEXT_MAIN.
  */
-#define TEXT_MAIN .text .text.[0-9a-zA-Z_]*
+#define TEXT_MAIN							\
+	.text								\
+	.text.[_0-9A-Za-df-rt-z]*					\
+	.text.s[_0-9A-Za-su-z]*						\
+	.text.st[_0-9A-Zb-z]*						\
+	.text.sta[_0-9A-Za-qs-z]*					\
+	.text.star[_0-9A-Za-su-z]*					\
+	.text.start[_0-9A-Za-tv-z]*					\
+	.text.startu[_0-9A-Za-oq-z]*					\
+	.text.startup[_0-9A-Za-z]*					\
+	.text.e[_0-9A-Za-wy-z]*						\
+	.text.ex[_0-9A-Za-hj-z]*					\
+	.text.exi[_0-9A-Za-su-z]*					\
+	.text.exit[_0-9A-Za-z]*
 
 /*
  * Support -fdata-sections by matching .data, .data.*, and others,
@@ -713,16 +729,16 @@
 
 #define INIT_TEXT							\
 	*(.init.text .init.text.*)					\
-	*(.text.startup)
+	*(.text.startup .text.startup.*)
 
 #define EXIT_DATA							\
 	*(.exit.data .exit.data.*)					\
 	*(.fini_array .fini_array.*)					\
-	*(.dtors .dtors.*)						\
+	*(.dtors .dtors.*)
 
 #define EXIT_TEXT							\
 	*(.exit.text)							\
-	*(.text.exit)							\
+	*(.text.exit .text.exit.*)
 
 #define EXIT_CALL							\
 	*(.exitcall.exit)