debug: Fix __bug_table[] in arch linker scripts

The kbuild test robot reported this build failure on a number
of architectures:

 >         make.cross ARCH=arm
 >    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'

Caused by:

  19d436268d ("debug: Add _ONCE() logic to report_bug()")

Which moved the BUG_TABLE from RO_DATA_SECTION() to RW_DATA_SECTION(),
but a number of architectures don't use RW_DATA_SECTION(), so they
ended up with no __bug_table[] ...

Ideally all those would use RW_DATA_SECTION() in their linker scripts,
but that's for another day.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kbuild test robot <fengguang.wu@intel.com>
Cc: kbuild-all@01.org
Cc: tipbuild@zytor.com
Link: http://lkml.kernel.org/r/20170330154927.o6qmgfp4bdhrajbm@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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

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

arch/avr32/kernel/vmlinux.lds.S

@@ -75,6 +75,7 @@ SECTIONS
 
 		_edata = .;
 	}
+	BUG_TABLE
 
 	BSS_SECTION(0, 8, 8)
 	_end = .;

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

arch/c6x/kernel/vmlinux.lds.S

@@ -128,6 +128,8 @@ SECTIONS
 		. = ALIGN(8);
 	}
 
+	BUG_TABLE
+
 	_edata = .;
 
 	__bss_start = .;

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. */

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;

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)

arch/mips/kernel/vmlinux.lds.S

@@ -97,6 +97,7 @@ SECTIONS
 		DATA_DATA
 		CONSTRUCTORS
 	}
+	BUG_TABLE
 	_gp = . + 0x8000;
 	.lit8 : {
 		*(.lit8)

arch/powerpc/kernel/vmlinux.lds.S

@@ -312,6 +312,8 @@ SECTIONS
 		NOSAVE_DATA
 	}
 
+	BUG_TABLE
+
 	. = ALIGN(PAGE_SIZE);
 	_edata  =  .;
 	PROVIDE32 (edata = .);

arch/x86/kernel/vmlinux.lds.S

@@ -146,6 +146,7 @@ SECTIONS
 		_edata = .;
 	} :data
 
+	BUG_TABLE
 
 	. = ALIGN(PAGE_SIZE);
 	__vvar_page = .;