openrisc: place exception table at the head of vmlinux

Since commit 0043ece ("vmlinux.lds.h: Adjust symbol ordering in text output section"), the exception table in arch/openrisc/kernel/head.S is no longer positioned at the very beginning of the kernel image, which causes a boot failure. Currently, the exception table resides in the regular .text section. Previously, it was placed at the head by relying on the linker receiving arch/openrisc/kernel/head.o as the first object. However, this behavior has changed because sections like .text.{asan,unknown,unlikely,hot} now precede the regular .text section. The .head.text section is intended for entry points requiring special placement. However, in OpenRISC, this section has been misused: instead of the entry points, it contains boot code meant to be discarded after booting. This feature is typically handled by the .init.text section. This commit addresses the issue by replacing the current __HEAD marker with __INIT and re-annotating the entry points with __HEAD. Additionally, it adds __REF to entry.S to suppress the following modpost warning: WARNING: modpost: vmlinux: section mismatch in reference: _tng_kernel_start+0x70 (section: .text) -> _start (section: .init.text) Fixes: 0043ece ("vmlinux.lds.h: Adjust symbol ordering in text output section") Reported-by: Guenter Roeck <[email protected]> Closes: https://lore.kernel.org/all/[email protected]/#t Signed-off-by: Masahiro Yamada <[email protected]> Tested-by: Guenter Roeck <[email protected]> Reviewed-by: Rong Xu <[email protected]> Signed-off-by: Stafford Horne <[email protected]>
linuxppc · Dec 10, 2024 · a412f04 · a412f04
1 parent fac04ef
commit a412f04
Show file tree

Hide file tree

Showing 4 changed files with 7 additions and 5 deletions.
diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S
@@ -239,6 +239,8 @@ handler:							;\
 
 /* =====================================================[ exceptions] === */
 
+	__REF
+
 /* ---[ 0x100: RESET exception ]----------------------------------------- */
 
 EXCEPTION_ENTRY(_tng_kernel_start)

diff --git a/arch/openrisc/kernel/head.S b/arch/openrisc/kernel/head.S
@@ -357,6 +357,8 @@
 
 /* =====================================================[ exceptions] === */
 
+	__HEAD
+
 /* ---[ 0x100: RESET exception ]----------------------------------------- */
     .org 0x100
 	/* Jump to .init code at _start which lives in the .head section
@@ -506,10 +508,10 @@ _dispatch_do_ipage_fault:
 
 /*    .text*/
 
-/* This early stuff belongs in HEAD, but some of the functions below definitely
+/* This early stuff belongs in the .init.text section, but some of the functions below definitely
  * don't... */
 
-	__HEAD
+	__INIT
 	.global _start
 _start:
 	/* Init r0 to zero as per spec */

diff --git a/arch/openrisc/kernel/vmlinux.lds.S b/arch/openrisc/kernel/vmlinux.lds.S
@@ -50,6 +50,7 @@ SECTIONS
         .text                   : AT(ADDR(.text) - LOAD_OFFSET)
 	{
           _stext = .;
+	  HEAD_TEXT
 	  TEXT_TEXT
 	  SCHED_TEXT
 	  LOCK_TEXT
@@ -83,8 +84,6 @@ SECTIONS
 	. = ALIGN(PAGE_SIZE);
 	__init_begin = .;
 
-	HEAD_TEXT_SECTION
-
 	/* Page aligned */
 	INIT_TEXT_SECTION(PAGE_SIZE)
 

diff --git a/scripts/head-object-list.txt b/scripts/head-object-list.txt
@@ -24,7 +24,6 @@ arch/m68k/kernel/head.o
 arch/m68k/kernel/sun3-head.o
 arch/microblaze/kernel/head.o
 arch/nios2/kernel/head.o
-arch/openrisc/kernel/head.o
 arch/parisc/kernel/head.o
 arch/powerpc/kernel/head_44x.o
 arch/powerpc/kernel/head_64.o
-Original file line number
+Diff line change
@@ Expand Up / @@ -239,6 +239,8 @@ handler: ;\ @@
     /* =====================================================[ exceptions] === */
+    	__REF
     /* ---[ 0x100: RESET exception ]----------------------------------------- */
     EXCEPTION_ENTRY(_tng_kernel_start)
@@ Expand Down @@