* [RFC 1/1] vmlinux.lds.h: Add new SECTION() macro
@ 2014-05-15 21:25 Geoff Levand
2014-05-16 10:12 ` Sam Ravnborg
0 siblings, 1 reply; 2+ messages in thread
From: Geoff Levand @ 2014-05-15 21:25 UTC (permalink / raw)
To: Michal Marek; +Cc: linux-kbuild, linux-kernel
Add a new preprocessor macro SECTION() to vmlinux.lds.h that defines a
linker script output section with the section attributes commonly used,
and replace all occurrences of equivalent descriptions in vmlinux.lds.h
with the new macro.
Based on linker script fixes in the commit log, creating or maintaining
linker script output section descriptions seems to be error prone, often
not having the correct section attributes. This new macro should help
to reduce these errors.
Signed-off-by: Geoff Levand <geoff@infradead.org>
---
Hi,
I thought I'd send this out to see if this is of interest. If so, I can
go through and apply the SECTION() macro to all the linker scripts in the
kernel. I think there are just under 100 possible replacements.
The name OUTPUT_SECTION() could also be used. It is a little more
descriptive.
Comments welcome.
-Geoff
include/asm-generic/vmlinux.lds.h | 66 ++++++++++++++++++++-------------------
1 file changed, 34 insertions(+), 32 deletions(-)
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 146e4ff..f9e3dce 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -64,6 +64,8 @@
#define STRUCT_ALIGNMENT 32
#define STRUCT_ALIGN() . = ALIGN(STRUCT_ALIGNMENT)
+#define SECTION(_x) _x : AT(ADDR(_x) - LOAD_OFFSET)
+
/* The actual configuration determine if the init/exit sections
* are handled as text/data or they can be discarded (which
* often happens at runtime)
@@ -248,7 +250,7 @@
*/
#define RO_DATA_SECTION(align) \
. = ALIGN((align)); \
- .rodata : AT(ADDR(.rodata) - LOAD_OFFSET) { \
+ SECTION(.rodata) { \
VMLINUX_SYMBOL(__start_rodata) = .; \
*(.rodata) *(.rodata.*) \
*(__vermagic) /* Kernel version magic */ \
@@ -259,14 +261,14 @@
*(__tracepoints_strings)/* Tracepoints: strings */ \
} \
\
- .rodata1 : AT(ADDR(.rodata1) - LOAD_OFFSET) { \
+ SECTION(.rodata1) { \
*(.rodata1) \
} \
\
BUG_TABLE \
\
/* PCI quirks */ \
- .pci_fixup : AT(ADDR(.pci_fixup) - LOAD_OFFSET) { \
+ SECTION(.pci_fixup) { \
VMLINUX_SYMBOL(__start_pci_fixups_early) = .; \
*(.pci_fixup_early) \
VMLINUX_SYMBOL(__end_pci_fixups_early) = .; \
@@ -291,7 +293,7 @@
} \
\
/* Built-in firmware blobs */ \
- .builtin_fw : AT(ADDR(.builtin_fw) - LOAD_OFFSET) { \
+ SECTION(.builtin_fw) { \
VMLINUX_SYMBOL(__start_builtin_fw) = .; \
*(.builtin_fw) \
VMLINUX_SYMBOL(__end_builtin_fw) = .; \
@@ -300,96 +302,96 @@
TRACEDATA \
\
/* Kernel symbol table: Normal symbols */ \
- __ksymtab : AT(ADDR(__ksymtab) - LOAD_OFFSET) { \
+ SECTION(__ksymtab) { \
VMLINUX_SYMBOL(__start___ksymtab) = .; \
*(SORT(___ksymtab+*)) \
VMLINUX_SYMBOL(__stop___ksymtab) = .; \
} \
\
/* Kernel symbol table: GPL-only symbols */ \
- __ksymtab_gpl : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) { \
+ SECTION(__ksymtab_gpl) { \
VMLINUX_SYMBOL(__start___ksymtab_gpl) = .; \
*(SORT(___ksymtab_gpl+*)) \
VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .; \
} \
\
/* Kernel symbol table: Normal unused symbols */ \
- __ksymtab_unused : AT(ADDR(__ksymtab_unused) - LOAD_OFFSET) { \
+ SECTION(__ksymtab_unused) { \
VMLINUX_SYMBOL(__start___ksymtab_unused) = .; \
*(SORT(___ksymtab_unused+*)) \
VMLINUX_SYMBOL(__stop___ksymtab_unused) = .; \
} \
\
/* Kernel symbol table: GPL-only unused symbols */ \
- __ksymtab_unused_gpl : AT(ADDR(__ksymtab_unused_gpl) - LOAD_OFFSET) { \
+ SECTION(__ksymtab_unused_gpl) { \
VMLINUX_SYMBOL(__start___ksymtab_unused_gpl) = .; \
*(SORT(___ksymtab_unused_gpl+*)) \
VMLINUX_SYMBOL(__stop___ksymtab_unused_gpl) = .; \
} \
\
/* Kernel symbol table: GPL-future-only symbols */ \
- __ksymtab_gpl_future : AT(ADDR(__ksymtab_gpl_future) - LOAD_OFFSET) { \
+ SECTION(__ksymtab_gpl_future) { \
VMLINUX_SYMBOL(__start___ksymtab_gpl_future) = .; \
*(SORT(___ksymtab_gpl_future+*)) \
VMLINUX_SYMBOL(__stop___ksymtab_gpl_future) = .; \
} \
\
/* Kernel symbol table: Normal symbols */ \
- __kcrctab : AT(ADDR(__kcrctab) - LOAD_OFFSET) { \
+ SECTION(__kcrctab) { \
VMLINUX_SYMBOL(__start___kcrctab) = .; \
*(SORT(___kcrctab+*)) \
VMLINUX_SYMBOL(__stop___kcrctab) = .; \
} \
\
/* Kernel symbol table: GPL-only symbols */ \
- __kcrctab_gpl : AT(ADDR(__kcrctab_gpl) - LOAD_OFFSET) { \
+ SECTION(__kcrctab_gpl) { \
VMLINUX_SYMBOL(__start___kcrctab_gpl) = .; \
*(SORT(___kcrctab_gpl+*)) \
VMLINUX_SYMBOL(__stop___kcrctab_gpl) = .; \
} \
\
/* Kernel symbol table: Normal unused symbols */ \
- __kcrctab_unused : AT(ADDR(__kcrctab_unused) - LOAD_OFFSET) { \
+ SECTION(__kcrctab_unused) { \
VMLINUX_SYMBOL(__start___kcrctab_unused) = .; \
*(SORT(___kcrctab_unused+*)) \
VMLINUX_SYMBOL(__stop___kcrctab_unused) = .; \
} \
\
/* Kernel symbol table: GPL-only unused symbols */ \
- __kcrctab_unused_gpl : AT(ADDR(__kcrctab_unused_gpl) - LOAD_OFFSET) { \
+ SECTION(__kcrctab_unused_gpl) { \
VMLINUX_SYMBOL(__start___kcrctab_unused_gpl) = .; \
*(SORT(___kcrctab_unused_gpl+*)) \
VMLINUX_SYMBOL(__stop___kcrctab_unused_gpl) = .; \
} \
\
/* Kernel symbol table: GPL-future-only symbols */ \
- __kcrctab_gpl_future : AT(ADDR(__kcrctab_gpl_future) - LOAD_OFFSET) { \
+ SECTION(__kcrctab_gpl_future) { \
VMLINUX_SYMBOL(__start___kcrctab_gpl_future) = .; \
*(SORT(___kcrctab_gpl_future+*)) \
VMLINUX_SYMBOL(__stop___kcrctab_gpl_future) = .; \
} \
\
/* Kernel symbol table: strings */ \
- __ksymtab_strings : AT(ADDR(__ksymtab_strings) - LOAD_OFFSET) { \
+ SECTION( __ksymtab_strings) { \
*(__ksymtab_strings) \
} \
\
/* __*init sections */ \
- __init_rodata : AT(ADDR(__init_rodata) - LOAD_OFFSET) { \
+ SECTION(__init_rodata) { \
*(.ref.rodata) \
MEM_KEEP(init.rodata) \
MEM_KEEP(exit.rodata) \
} \
\
/* Built-in module parameters. */ \
- __param : AT(ADDR(__param) - LOAD_OFFSET) { \
+ SECTION(__param) { \
VMLINUX_SYMBOL(__start___param) = .; \
*(__param) \
VMLINUX_SYMBOL(__stop___param) = .; \
} \
\
/* Built-in module versions. */ \
- __modver : AT(ADDR(__modver) - LOAD_OFFSET) { \
+ SECTION(__modver) { \
VMLINUX_SYMBOL(__start___modver) = .; \
*(__modver) \
VMLINUX_SYMBOL(__stop___modver) = .; \
@@ -404,7 +406,7 @@
#define RO_DATA(align) RO_DATA_SECTION(align)
#define SECURITY_INIT \
- .security_initcall.init : AT(ADDR(.security_initcall.init) - LOAD_OFFSET) { \
+ SECTION(.security_initcall.init) { \
VMLINUX_SYMBOL(__security_initcall_start) = .; \
*(.security_initcall.init) \
VMLINUX_SYMBOL(__security_initcall_end) = .; \
@@ -463,8 +465,8 @@
/* Section used for early init (in .S files) */
#define HEAD_TEXT *(.head.text)
-#define HEAD_TEXT_SECTION \
- .head.text : AT(ADDR(.head.text) - LOAD_OFFSET) { \
+#define HEAD_TEXT_SECTION \
+ SECTION(.head.text) { \
HEAD_TEXT \
}
@@ -473,7 +475,7 @@
*/
#define EXCEPTION_TABLE(align) \
. = ALIGN(align); \
- __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) { \
+ SECTION(__ex_table) { \
VMLINUX_SYMBOL(__start___ex_table) = .; \
*(__ex_table) \
VMLINUX_SYMBOL(__stop___ex_table) = .; \
@@ -484,7 +486,7 @@
*/
#define INIT_TASK_DATA_SECTION(align) \
. = ALIGN(align); \
- .data..init_task : AT(ADDR(.data..init_task) - LOAD_OFFSET) { \
+ SECTION(.data..init_task) { \
INIT_TASK_DATA(align) \
}
@@ -537,7 +539,7 @@
*/
#define SBSS(sbss_align) \
. = ALIGN(sbss_align); \
- .sbss : AT(ADDR(.sbss) - LOAD_OFFSET) { \
+ SECTION(.sbss) { \
*(.sbss) \
*(.scommon) \
}
@@ -552,7 +554,7 @@
#define BSS(bss_align) \
. = ALIGN(bss_align); \
- .bss : AT(ADDR(.bss) - LOAD_OFFSET) { \
+ SECTION(.bss) { \
BSS_FIRST_SECTIONS \
*(.bss..page_aligned) \
*(.dynbss) \
@@ -603,7 +605,7 @@
#ifdef CONFIG_GENERIC_BUG
#define BUG_TABLE \
. = ALIGN(8); \
- __bug_table : AT(ADDR(__bug_table) - LOAD_OFFSET) { \
+ SECTION(__bug_table) { \
VMLINUX_SYMBOL(__start___bug_table) = .; \
*(__bug_table) \
VMLINUX_SYMBOL(__stop___bug_table) = .; \
@@ -615,7 +617,7 @@
#ifdef CONFIG_PM_TRACE
#define TRACEDATA \
. = ALIGN(4); \
- .tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) { \
+ SECTION(.tracedata) { \
VMLINUX_SYMBOL(__tracedata_start) = .; \
*(.tracedata) \
VMLINUX_SYMBOL(__tracedata_end) = .; \
@@ -625,7 +627,7 @@
#endif
#define NOTES \
- .notes : AT(ADDR(.notes) - LOAD_OFFSET) { \
+ SECTION(.notes) { \
VMLINUX_SYMBOL(__start_notes) = .; \
*(.note.*) \
VMLINUX_SYMBOL(__stop_notes) = .; \
@@ -763,7 +765,7 @@
*/
#define PERCPU_SECTION(cacheline) \
. = ALIGN(PAGE_SIZE); \
- .data..percpu : AT(ADDR(.data..percpu) - LOAD_OFFSET) { \
+ SECTION(.data..percpu) { \
VMLINUX_SYMBOL(__per_cpu_load) = .; \
PERCPU_INPUT(cacheline) \
}
@@ -789,7 +791,7 @@
* use 0 as page_align if page_aligned data is not used */
#define RW_DATA_SECTION(cacheline, pagealigned, inittask) \
. = ALIGN(PAGE_SIZE); \
- .data : AT(ADDR(.data) - LOAD_OFFSET) { \
+ SECTION(.data) { \
INIT_TASK_DATA(inittask) \
NOSAVE_DATA \
PAGE_ALIGNED_DATA(pagealigned) \
@@ -801,14 +803,14 @@
#define INIT_TEXT_SECTION(inittext_align) \
. = ALIGN(inittext_align); \
- .init.text : AT(ADDR(.init.text) - LOAD_OFFSET) { \
+ SECTION(.init.text) { \
VMLINUX_SYMBOL(_sinittext) = .; \
INIT_TEXT \
VMLINUX_SYMBOL(_einittext) = .; \
}
#define INIT_DATA_SECTION(initsetup_align) \
- .init.data : AT(ADDR(.init.data) - LOAD_OFFSET) { \
+ SECTION(.init.data) { \
INIT_DATA \
INIT_SETUP(initsetup_align) \
INIT_CALLS \
--
1.9.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [RFC 1/1] vmlinux.lds.h: Add new SECTION() macro
2014-05-15 21:25 [RFC 1/1] vmlinux.lds.h: Add new SECTION() macro Geoff Levand
@ 2014-05-16 10:12 ` Sam Ravnborg
0 siblings, 0 replies; 2+ messages in thread
From: Sam Ravnborg @ 2014-05-16 10:12 UTC (permalink / raw)
To: Geoff Levand; +Cc: Michal Marek, linux-kbuild, linux-kernel
On Thu, May 15, 2014 at 02:25:58PM -0700, Geoff Levand wrote:
> Add a new preprocessor macro SECTION() to vmlinux.lds.h that defines a
> linker script output section with the section attributes commonly used,
> and replace all occurrences of equivalent descriptions in vmlinux.lds.h
> with the new macro.
Looks good - but the name is too generic.
Use OUTPUT_SECTION() as you suggest in the comment below.
If you walk through all linker scripts then keep an eay out for
stuff where the generic stuff can be used.
And see if there is something else that really belongs in asm-generic.
Sam
^ permalink raw reply [flat|nested] 2+ messages in thread
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