From 405d967dc70002991f8fc35c20e0d3cbc7614f63 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 24 Jun 2009 15:13:38 +0900 Subject: linker script: throw away .discard section x86 throws away .discard section but no other archs do. Also, .discard is not thrown away while linking modules. Make every arch and module linking throw it away. This will be used to define dummy variables for percpu declarations and definitions. This patch is based on Ivan Kokshaysky's alpha percpu patch. [ Impact: always throw away everything in .discard ] Signed-off-by: Tejun Heo Cc: Ivan Kokshaysky Cc: Richard Henderson Cc: Russell King Cc: Haavard Skinnemoen Cc: Bryan Wu Cc: Mikael Starvik Cc: Jesper Nilsson Cc: David Howells Cc: Yoshinori Sato Cc: Tony Luck Cc: Hirokazu Takata Cc: Geert Uytterhoeven Cc: Michal Simek Cc: Ralf Baechle Cc: Kyle McMartin Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Paul Mundt Cc: David S. Miller Cc: Jeff Dike Cc: Chris Zankel Cc: Rusty Russell Cc: Ingo Molnar --- include/asm-generic/vmlinux.lds.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/asm-generic/vmlinux.lds.h') diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 55413e568f07..a19120c4e109 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -628,6 +628,14 @@ #define INITRAMFS #endif +#define DISCARDS \ + /DISCARD/ : { \ + EXIT_TEXT \ + EXIT_DATA \ + *(.exitcall.exit) \ + *(.discard) \ + } + /** * PERCPU_VADDR - define output section for percpu area * @vaddr: explicit base address (optional) -- cgit v1.2.1 From 023bf6f1b8bf58dc4da7f0dc1cf4787b0d5297c1 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 9 Jul 2009 11:27:40 +0900 Subject: linker script: unify usage of discard definition Discarded sections in different archs share some commonality but have considerable differences. This led to linker script for each arch implementing its own /DISCARD/ definition, which makes maintaining tedious and adding new entries error-prone. This patch makes all linker scripts to move discard definitions to the end of the linker script and use the common DISCARDS macro. As ld uses the first matching section definition, archs can include default discarded sections by including them earlier in the linker script. ia64 is notable because it first throws away some ia64 specific subsections and then include the rest of the sections into the final image, so those sections must be discarded before the inclusion. defconfig compile tested for x86, x86-64, powerpc, powerpc64, ia64, alpha, sparc, sparc64 and s390. Michal Simek tested microblaze. Signed-off-by: Tejun Heo Acked-by: Paul Mundt Acked-by: Mike Frysinger Tested-by: Michal Simek Cc: linux-arch@vger.kernel.org Cc: Michal Simek Cc: microblaze-uclinux@itee.uq.edu.au Cc: Sam Ravnborg Cc: Tony Luck --- include/asm-generic/vmlinux.lds.h | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'include/asm-generic/vmlinux.lds.h') diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index c5c18ac878ab..ab8ea9b7741e 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -35,13 +35,10 @@ * __bss_stop = .; * _end = .; * - * /DISCARD/ : { - * EXIT_TEXT - * EXIT_DATA - * EXIT_CALL - * } * STABS_DEBUG * DWARF_DEBUG + * + * DISCARDS // must be the last * } * * [__init_begin, __init_end] is the init section that may be freed after init @@ -629,11 +626,20 @@ #define INIT_RAM_FS #endif +/* + * Default discarded sections. + * + * Some archs want to discard exit text/data at runtime rather than + * link time due to cross-section references such as alt instructions, + * bug table, eh_frame, etc. DISCARDS must be the last of output + * section definitions so that such archs put those in earlier section + * definitions. + */ #define DISCARDS \ /DISCARD/ : { \ EXIT_TEXT \ EXIT_DATA \ - *(.exitcall.exit) \ + EXIT_CALL \ *(.discard) \ } -- cgit v1.2.1