Re: [tip:x86/asm 3/3] lib/bug.c:135: undefined reference to `__start___bug_table'

[Peter Zijlstra <peterz@infradead.org>]

On Thu, Mar 30, 2017 at 09:02:31PM +0800, kbuild test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/asm
> head:   19d436268dde95389c616bb3819da73f0a8b28a8
> commit: 19d436268dde95389c616bb3819da73f0a8b28a8 [3/3] debug: Add _ONCE() logic to report_bug()
> config: arm-efm32_defconfig (attached as .config)
> compiler: arm-linux-gnueabi-gcc (Debian 6.1.1-9) 6.1.1 20160705
> reproduce:
>         wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         git checkout 19d436268dde95389c616bb3819da73f0a8b28a8
>         # save the attached .config to linux build tree
>         make.cross ARCH=arm 
> 
> All errors (new ones prefixed by >>):
> 
>    lib/lib.a(bug.o): In function `find_bug':
> >> lib/bug.c:135: undefined reference to `__start___bug_table'
> >> lib/bug.c:135: undefined reference to `__stop___bug_table'

Blergh.. this cures it for me.

Ideally all those would use RW_DATA_SECTION, but alas.

---
 arch/arm/kernel/vmlinux-xip.lds.S  | 2 ++
 arch/arm/kernel/vmlinux.lds.S      | 2 ++
 arch/avr32/kernel/vmlinux.lds.S    | 1 +
 arch/blackfin/kernel/vmlinux.lds.S | 2 ++
 arch/c6x/kernel/vmlinux.lds.S      | 2 ++
 arch/cris/kernel/vmlinux.lds.S     | 2 ++
 arch/frv/kernel/vmlinux.lds.S      | 2 ++
 arch/ia64/kernel/vmlinux.lds.S     | 2 ++
 arch/mips/kernel/vmlinux.lds.S     | 1 +
 arch/powerpc/kernel/vmlinux.lds.S  | 2 ++
 arch/x86/kernel/vmlinux.lds.S      | 1 +
 11 files changed, 19 insertions(+)

diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S
index 37b2a11..8265b11 100644
--- a/arch/arm/kernel/vmlinux-xip.lds.S
+++ b/arch/arm/kernel/vmlinux-xip.lds.S
@@ -242,6 +242,8 @@ SECTIONS
 	}
 	_edata_loc = __data_loc + SIZEOF(.data);
 
+	BUG_TABLE
+
 #ifdef CONFIG_HAVE_TCM
         /*
 	 * We align everything to a page boundary so we can
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index ce18007..c83a7ba 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -262,6 +262,8 @@ SECTIONS
 	}
 	_edata_loc = __data_loc + SIZEOF(.data);
 
+	BUG_TABLE
+
 #ifdef CONFIG_HAVE_TCM
         /*
 	 * We align everything to a page boundary so we can
diff --git a/arch/avr32/kernel/vmlinux.lds.S b/arch/avr32/kernel/vmlinux.lds.S
index 17f2730..623d18d 100644
--- a/arch/avr32/kernel/vmlinux.lds.S
+++ b/arch/avr32/kernel/vmlinux.lds.S
@@ -75,6 +75,7 @@ SECTIONS
 
 		_edata = .;
 	}
+	BUG_TABLE
 
 	BSS_SECTION(0, 8, 8)
 	_end = .;
diff --git a/arch/blackfin/kernel/vmlinux.lds.S b/arch/blackfin/kernel/vmlinux.lds.S
index 68069a1..334ef81 100644
--- a/arch/blackfin/kernel/vmlinux.lds.S
+++ b/arch/blackfin/kernel/vmlinux.lds.S
@@ -115,6 +115,8 @@ SECTIONS
 	__data_lma = LOADADDR(.data);
 	__data_len = SIZEOF(.data);
 
+	BUG_TABLE
+
 	/* The init section should be last, so when we free it, it goes into
 	 * the general memory pool, and (hopefully) will decrease fragmentation
 	 * a tiny bit. The init section has a _requirement_ that it be
diff --git a/arch/c6x/kernel/vmlinux.lds.S b/arch/c6x/kernel/vmlinux.lds.S
index a1a5c16..29ebea4 100644
--- a/arch/c6x/kernel/vmlinux.lds.S
+++ b/arch/c6x/kernel/vmlinux.lds.S
@@ -128,6 +128,8 @@ SECTIONS
 		. = ALIGN(8);
 	}
 
+	BUG_TABLE
+
 	_edata = .;
 
 	__bss_start = .;
diff --git a/arch/cris/kernel/vmlinux.lds.S b/arch/cris/kernel/vmlinux.lds.S
index 9795862..867f237 100644
--- a/arch/cris/kernel/vmlinux.lds.S
+++ b/arch/cris/kernel/vmlinux.lds.S
@@ -68,6 +68,8 @@ SECTIONS
 	__edata = . ;			/* End of data section. */
 	_edata = . ;
 
+	BUG_TABLE
+
 	INIT_TASK_DATA_SECTION(PAGE_SIZE)
 
 	. = ALIGN(PAGE_SIZE);		/* Init code and data. */
diff --git a/arch/frv/kernel/vmlinux.lds.S b/arch/frv/kernel/vmlinux.lds.S
index aa6e573..3f44dcb 100644
--- a/arch/frv/kernel/vmlinux.lds.S
+++ b/arch/frv/kernel/vmlinux.lds.S
@@ -102,6 +102,8 @@ SECTIONS
 
   _edata = .;			/* End of data section */
 
+  BUG_TABLE
+
   /* GP section */
   . = ALIGN(L1_CACHE_BYTES);
   _gp = . + 2048;
diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index f89d20c..798026d 100644
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -192,6 +192,8 @@ SECTIONS {
 		CONSTRUCTORS
 	}
 
+	BUG_TABLE
+
 	. = ALIGN(16);	/* gp must be 16-byte aligned for exc. table */
 	.got : AT(ADDR(.got) - LOAD_OFFSET) {
 		*(.got.plt)
diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
index f0a0e6d..8ca2371 100644
--- a/arch/mips/kernel/vmlinux.lds.S
+++ b/arch/mips/kernel/vmlinux.lds.S
@@ -97,6 +97,7 @@ SECTIONS
 		DATA_DATA
 		CONSTRUCTORS
 	}
+	BUG_TABLE
 	_gp = . + 0x8000;
 	.lit8 : {
 		*(.lit8)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 7394b77..1c24c89 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -312,6 +312,8 @@ SECTIONS
 		NOSAVE_DATA
 	}
 
+	BUG_TABLE
+
 	. = ALIGN(PAGE_SIZE);
 	_edata  =  .;
 	PROVIDE32 (edata = .);
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index c74ae9c..c8a3b61 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -146,6 +146,7 @@ SECTIONS
 		_edata = .;
 	} :data
 
+	BUG_TABLE
 
 	. = ALIGN(PAGE_SIZE);
 	__vvar_page = .;