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linux/scripts/module-common.lds

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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 <tj@kernel.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Richard Henderson <rth@twiddle.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Bryan Wu <cooloney@kernel.org> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Tony Luck <tony.luck@intel.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: David S. Miller <davem@davemloft.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Chris Zankel <chris@zankel.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu>
2009-06-24 15:13:38 +09:00
objtool, modules: Discard objtool annotation sections for modules The '__unreachable' and '__func_stack_frame_non_standard' sections are only used at compile time. They're discarded for vmlinux but they should also be discarded for modules. Since this is a recurring pattern, prefix the section names with ".discard.". It's a nice convention and vmlinux.lds.h already discards such sections. Also remove the 'a' (allocatable) flag from the __unreachable section since it doesn't make sense for a discarded section. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jessica Yu <jeyu@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead ends") Link: http://lkml.kernel.org/r/20170301180444.lhd53c5tibc4ns77@treble Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-01 12:04:44 -06:00
module: Sort exported symbols This patch places every exported symbol in its own section (i.e. "___ksymtab+printk"). Thus the linker will use its SORT() directive to sort and finally merge all symbol in the right and final section (i.e. "__ksymtab"). The symbol prefixed archs use an underscore as prefix for symbols. To avoid collision we use a different character to create the temporary section names. This work was supported by a hardware donation from the CE Linux Forum. Signed-off-by: Alessio Igor Bogani <abogani@kernel.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (folded in '+' fixup) Tested-by: Dirk Behme <dirk.behme@googlemail.com>
2011-04-14 14:59:39 +02:00
module: set ksymtab/kcrctab* section addresses to 0x0 These __ksymtab*/__kcrctab* sections currently have non-zero addresses. Non-zero section addresses in a relocatable ELF confuse GDB and it ends up not relocating all symbols when add-symbol-file is used on modules which have exports. The kernel's module loader does not care about these addresses, so let's just set them to zero. Before: $ readelf -S lib/notifier-error-inject.ko | grep 'Name\| __ksymtab_gpl' [Nr] Name Type Addr Off Size ES Flg Lk Inf Al [ 8] __ksymtab_gpl PROGBITS 0000000c 0001b4 000010 00 A 0 0 4 (gdb) add-symbol-file lib/notifier-error-inject.ko 0x500000 -s .bss 0x700000 add symbol table from file "lib/notifier-error-inject.ko" at .text_addr = 0x500000 .bss_addr = 0x700000 (gdb) p &notifier_err_inject_dir $3 = (struct dentry **) 0x0 After: $ readelf -S lib/notifier-error-inject.ko | grep 'Name\| __ksymtab_gpl' [Nr] Name Type Addr Off Size ES Flg Lk Inf Al [ 8] __ksymtab_gpl PROGBITS 00000000 0001b4 000010 00 A 0 0 4 (gdb) add-symbol-file lib/notifier-error-inject.ko 0x500000 -s .bss 0x700000 add symbol table from file "lib/notifier-error-inject.ko" at .text_addr = 0x500000 .bss_addr = 0x700000 (gdb) p &notifier_err_inject_dir $3 = (struct dentry **) 0x700000 Signed-off-by: Rabin Vincent <rabin.vincent@axis.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-02-06 15:09:57 +10:30
kernel: add support for .init_array.* constructors KASan uses constructors for initializing redzones for global variables. Globals instrumentation in GCC 4.9.2 produces constructors with priority (.init_array.00099) Currently kernel ignores such constructors. Only constructors with default priority supported (.init_array) This patch adds support for constructors with priorities. For kernel image we put pointers to constructors between __ctors_start/__ctors_end and do_ctors() will call them on start up. For modules we merge .init_array.* sections into resulting .init_array. Module code properly handles constructors in .init_array section. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrey Konovalov <adech.fo@gmail.com> Cc: Yuri Gribov <tetra2005@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 14:40:10 -08:00
module: set .init_array alignment to 8 The proper idiom for aligning linker sections in modules is different than for built-in sections. ". = ALIGN();" followed by a forced output address of 0 does nothing, as forcing the address changes the value of ".". Use output section alignment specifier instead. Fixes: 9ddf82521c86 ("kernel: add support for .init_array.* constructors") Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Jessica Yu <jeyu@redhat.com>
2017-03-07 17:31:08 -08:00
module: set __jump_table alignment to 8 For powerpc the __jump_table section in modules is not aligned, this causes a WARN_ON() splat when loading a module containing a __jump_table. Strict alignment became necessary with commit 3821fd35b58d ("jump_label: Reduce the size of struct static_key"), currently in linux-next, which uses the two least significant bits of pointers to __jump_table elements. Fix by forcing __jump_table to 8, which is the same alignment used for this section in the kernel proper. Link: http://lkml.kernel.org/r/20170301220453.4756-1-david.daney@cavium.com Reviewed-by: Jason Baron <jbaron@akamai.com> Acked-by: Jessica Yu <jeyu@redhat.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-03-01 14:04:53 -08:00
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 <tj@kernel.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Richard Henderson <rth@twiddle.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Bryan Wu <cooloney@kernel.org> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Tony Luck <tony.luck@intel.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: David S. Miller <davem@davemloft.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Chris Zankel <chris@zankel.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu>
2009-06-24 15:13:38 +09:00