[tip:x86/urgent] x86: Fix build with older binutils and consolidate linker script

[tip:x86/urgent] x86: Fix build with older binutils and consolidate linker script

[tip-bot for Jan Beulich]

Commit-ID:  ddc98b38b6320d5de2e3167673a06ec1a48e9d0e
Gitweb:     http://git.kernel.org/tip/ddc98b38b6320d5de2e3167673a06ec1a48e9d0e
Author:     Jan Beulich <JBeulich@novell.com>
AuthorDate: Tue, 18 Aug 2009 16:51:27 +0100
Committer:  H. Peter Anvin <hpa@zytor.com>
CommitDate: Mon, 24 Aug 2009 15:51:35 -0700

x86: Fix build with older binutils and consolidate linker script

binutils prior to 2.17 can't deal with the currently possible situation
of a new segment following the per-CPU segment, but that new segment
being empty - objcopy misplaces the .bss (and perhaps also the .brk)
sections outside of any segment. However, the current ordering of
sections really just appears to be the effect of cumulative unrelated
changes; re-ordering things allows to easily guarantee that the segment
following the per-CPU one is non-empty, and at once eliminates the need
for the bogus data.init2 segment.

Once touching this code, also use the various data section helper
macros from include/asm-generic/vmlinux.lds.h.

[ Impact: build fix ]

Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <4A8AEA1F0200007800010563@vpn.id2.novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>


---
 arch/x86/kernel/vmlinux.lds.S |  126 +++++++++++++++-------------------------
 1 files changed, 47 insertions(+), 79 deletions(-)

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 78d185d..9fbcd5b 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -46,11 +46,10 @@ PHDRS {
 	data PT_LOAD FLAGS(7);          /* RWE */
 #ifdef CONFIG_X86_64
 	user PT_LOAD FLAGS(7);          /* RWE */
-	data.init PT_LOAD FLAGS(7);     /* RWE */
 #ifdef CONFIG_SMP
 	percpu PT_LOAD FLAGS(7);        /* RWE */
+	init PT_LOAD FLAGS(7);          /* RWE */
 #endif
-	data.init2 PT_LOAD FLAGS(7);    /* RWE */
 #endif
 	note PT_NOTE FLAGS(0);          /* ___ */
 }
@@ -103,65 +102,43 @@ SECTIONS
 		__stop___ex_table = .;
 	} :text = 0x9090
 
-	RODATA
+	RO_DATA(PAGE_SIZE)
 
 	/* Data */
-	. = ALIGN(PAGE_SIZE);
 	.data : AT(ADDR(.data) - LOAD_OFFSET) {
 		/* Start of data section */
 		_sdata = .;
-		DATA_DATA
-		CONSTRUCTORS
-	} :data
+
+		/* init_task */
+		INIT_TASK_DATA(THREAD_SIZE)
 
 #ifdef CONFIG_X86_32
-	/* 32 bit has nosave before _edata */
-	. = ALIGN(PAGE_SIZE);
-	.data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
-		__nosave_begin = .;
-		*(.data.nosave)
-		. = ALIGN(PAGE_SIZE);
-		__nosave_end = .;
-	}
+		/* 32 bit has nosave before _edata */
+		NOSAVE_DATA
 #endif
 
-	. = ALIGN(PAGE_SIZE);
-	.data.page_aligned : AT(ADDR(.data.page_aligned) - LOAD_OFFSET) {
-		*(.data.page_aligned)
+		PAGE_ALIGNED_DATA(PAGE_SIZE)
 		*(.data.idt)
-	}
 
-#ifdef CONFIG_X86_32
-	. = ALIGN(32);
-#else
-	. = ALIGN(PAGE_SIZE);
-	. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
-#endif
-	.data.cacheline_aligned :
-		AT(ADDR(.data.cacheline_aligned) - LOAD_OFFSET) {
-		*(.data.cacheline_aligned)
-	}
+		CACHELINE_ALIGNED_DATA(CONFIG_X86_L1_CACHE_BYTES)
 
-	/* rarely changed data like cpu maps */
-#ifdef CONFIG_X86_32
-	. = ALIGN(32);
-#else
-	. = ALIGN(CONFIG_X86_INTERNODE_CACHE_BYTES);
-#endif
-	.data.read_mostly : AT(ADDR(.data.read_mostly) - LOAD_OFFSET) {
-		*(.data.read_mostly)
+		DATA_DATA
+		CONSTRUCTORS
+
+		/* rarely changed data like cpu maps */
+		READ_MOSTLY_DATA(CONFIG_X86_INTERNODE_CACHE_BYTES)
 
 		/* End of data section */
 		_edata = .;
-	}
+	} :data
 
 #ifdef CONFIG_X86_64
 
 #define VSYSCALL_ADDR (-10*1024*1024)
-#define VSYSCALL_PHYS_ADDR ((LOADADDR(.data.read_mostly) + \
-                            SIZEOF(.data.read_mostly) + 4095) & ~(4095))
-#define VSYSCALL_VIRT_ADDR ((ADDR(.data.read_mostly) + \
-                            SIZEOF(.data.read_mostly) + 4095) & ~(4095))
+#define VSYSCALL_PHYS_ADDR ((LOADADDR(.data) + SIZEOF(.data) + \
+                            PAGE_SIZE - 1) & ~(PAGE_SIZE - 1))
+#define VSYSCALL_VIRT_ADDR ((ADDR(.data) + SIZEOF(.data) + \
+                            PAGE_SIZE - 1) & ~(PAGE_SIZE - 1))
 
 #define VLOAD_OFFSET (VSYSCALL_ADDR - VSYSCALL_PHYS_ADDR)
 #define VLOAD(x) (ADDR(x) - VLOAD_OFFSET)
@@ -227,35 +204,29 @@ SECTIONS
 
 #endif /* CONFIG_X86_64 */
 
-	/* init_task */
-	. = ALIGN(THREAD_SIZE);
-	.data.init_task : AT(ADDR(.data.init_task) - LOAD_OFFSET) {
-		*(.data.init_task)
+	/* Init code and data - will be freed after init */
+	. = ALIGN(PAGE_SIZE);
+	.init.begin : AT(ADDR(.init.begin) - LOAD_OFFSET) {
+		__init_begin = .; /* paired with __init_end */
 	}
-#ifdef CONFIG_X86_64
-	 :data.init
-#endif
 
+#if defined(CONFIG_X86_64) && defined(CONFIG_SMP)
 	/*
-	 * smp_locks might be freed after init
-	 * start/end must be page aligned
+	 * percpu offsets are zero-based on SMP.  PERCPU_VADDR() changes the
+	 * output PHDR, so the next output section - .init.text - should
+	 * start another segment - init.
 	 */
-	. = ALIGN(PAGE_SIZE);
-	.smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
-		__smp_locks = .;
-		*(.smp_locks)
-		__smp_locks_end = .;
-		. = ALIGN(PAGE_SIZE);
-	}
+	PERCPU_VADDR(0, :percpu)
+#endif
 
-	/* Init code and data - will be freed after init */
-	. = ALIGN(PAGE_SIZE);
 	.init.text : AT(ADDR(.init.text) - LOAD_OFFSET) {
-		__init_begin = .; /* paired with __init_end */
 		_sinittext = .;
 		INIT_TEXT
 		_einittext = .;
 	}
+#if defined(CONFIG_X86_64) && defined(CONFIG_SMP)
+	:init
+#endif
 
 	.init.data : AT(ADDR(.init.data) - LOAD_OFFSET) {
 		INIT_DATA
@@ -326,17 +297,7 @@ SECTIONS
 	}
 #endif
 
-#if defined(CONFIG_X86_64) && defined(CONFIG_SMP)
-	/*
-	 * percpu offsets are zero-based on SMP.  PERCPU_VADDR() changes the
-	 * output PHDR, so the next output section - __data_nosave - should
-	 * start another section data.init2.  Also, pda should be at the head of
-	 * percpu area.  Preallocate it and define the percpu offset symbol
-	 * so that it can be accessed as a percpu variable.
-	 */
-	. = ALIGN(PAGE_SIZE);
-	PERCPU_VADDR(0, :percpu)
-#else
+#if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP)
 	PERCPU(PAGE_SIZE)
 #endif
 
@@ -347,15 +308,22 @@ SECTIONS
 		__init_end = .;
 	}
 
+	/*
+	 * smp_locks might be freed after init
+	 * start/end must be page aligned
+	 */
+	. = ALIGN(PAGE_SIZE);
+	.smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
+		__smp_locks = .;
+		*(.smp_locks)
+		__smp_locks_end = .;
+		. = ALIGN(PAGE_SIZE);
+	}
+
 #ifdef CONFIG_X86_64
 	.data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
-		. = ALIGN(PAGE_SIZE);
-		__nosave_begin = .;
-		*(.data.nosave)
-		. = ALIGN(PAGE_SIZE);
-		__nosave_end = .;
-	} :data.init2
-	/* use another section data.init2, see PERCPU_VADDR() above */
+		NOSAVE_DATA
+	}
 #endif
 
 	/* BSS */

Re: [tip:x86/urgent] x86: Fix build with older binutils and consolidate linker script

[Ingo Molnar]

* tip-bot for Jan Beulich <JBeulich@novell.com> wrote:

> Commit-ID:  ddc98b38b6320d5de2e3167673a06ec1a48e9d0e
> Gitweb:     http://git.kernel.org/tip/ddc98b38b6320d5de2e3167673a06ec1a48e9d0e
> Author:     Jan Beulich <JBeulich@novell.com>
> AuthorDate: Tue, 18 Aug 2009 16:51:27 +0100
> Committer:  H. Peter Anvin <hpa@zytor.com>
> CommitDate: Mon, 24 Aug 2009 15:51:35 -0700
> 
> x86: Fix build with older binutils and consolidate linker script

this breaks the build with newer binutils:

  LD      .tmp_vmlinux1
ld: .tmp_vmlinux1: section `.init.text' can't be allocated in segment 2
LOAD: .vsyscall_0 .vsyscall_fn .vsyscall_gtod_data .vsyscall_1 
.vsyscall_2 .vgetcpu_mode .jiffies .init.text .init.data .init.setup 
.initcall.init .con_initcall.init .x86_cpu_dev.init 
.security_initcall.init .parainstructions .altinstructions 
.altinstr_replacement .exit.text .bss .brk
ld: final link failed: Bad value
make: *** [.tmp_vmlinux1] Error 1

	Ingo

Re: [tip:x86/urgent] x86: Fix build with older binutils and consolidate linker script

[Jan Beulich]

Was that using a UP config perhaps?

Jan

>>> Ingo Molnar <mingo@elte.hu> 25.08.09 09:50 >>>

* tip-bot for Jan Beulich <JBeulich@novell.com> wrote:

> Commit-ID:  ddc98b38b6320d5de2e3167673a06ec1a48e9d0e
> Gitweb:     http://git.kernel.org/tip/ddc98b38b6320d5de2e3167673a06ec1a48e9d0e 
> Author:     Jan Beulich <JBeulich@novell.com>
> AuthorDate: Tue, 18 Aug 2009 16:51:27 +0100
> Committer:  H. Peter Anvin <hpa@zytor.com>
> CommitDate: Mon, 24 Aug 2009 15:51:35 -0700
> 
> x86: Fix build with older binutils and consolidate linker script

this breaks the build with newer binutils:

  LD      .tmp_vmlinux1
ld: .tmp_vmlinux1: section `.init.text' can't be allocated in segment 2
LOAD: .vsyscall_0 .vsyscall_fn .vsyscall_gtod_data .vsyscall_1 
.vsyscall_2 .vgetcpu_mode .jiffies .init.text .init.data .init.setup 
.initcall.init .con_initcall.init .x86_cpu_dev.init 
.security_initcall.init .parainstructions .altinstructions 
.altinstr_replacement .exit.text .bss .brk
ld: final link failed: Bad value
make: *** [.tmp_vmlinux1] Error 1

	Ingo

Re: [tip:x86/urgent] x86: Fix build with older binutils and consolidate linker script

[Ingo Molnar]

* Jan Beulich <JBeulich@novell.com> wrote:

> Was that using a UP config perhaps?

yeah - UP 64-bit.

	Ingo

[PATCH] x86: fix build with older binutils and consolidate linker script (v2)

[Jan Beulich]

Impact: build fix

binutils prior to 2.17 can't deal with the currently possible situation
of a new segment following the per-CPU segment, but that new segment
being empty - objcopy misplaces the .bss (and perhaps also the .brk)
sections outside of any segment. However, the current ordering of
sections really just appears to be the effect of cumulative unrelated
changes; re-ordering things allows to easily guarantee that the segment
following the per-CPU one is non-empty, and at once eliminates the need
for the bogus data.init2 segment.

Once touching this code, also use the various data section helper
macros from include/asm-generic/vmlinux.lds.h.

Change from previous submission is an adjustment to fix !SMP builds.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

---
 arch/x86/kernel/vmlinux.lds.S |  126 +++++++++++++++---------------------------
 1 file changed, 47 insertions(+), 79 deletions(-)

--- linux-2.6.31-rc7/arch/x86/kernel/vmlinux.lds.S	2009-08-25 15:16:34.000000000 +0200
+++ 2.6.31-rc7-x86-link-order/arch/x86/kernel/vmlinux.lds.S	2009-08-25 15:36:42.000000000 +0200
@@ -46,11 +46,10 @@ PHDRS {
 	data PT_LOAD FLAGS(7);          /* RWE */
 #ifdef CONFIG_X86_64
 	user PT_LOAD FLAGS(7);          /* RWE */
-	data.init PT_LOAD FLAGS(7);     /* RWE */
 #ifdef CONFIG_SMP
 	percpu PT_LOAD FLAGS(7);        /* RWE */
 #endif
-	data.init2 PT_LOAD FLAGS(7);    /* RWE */
+	init PT_LOAD FLAGS(7);          /* RWE */
 #endif
 	note PT_NOTE FLAGS(0);          /* ___ */
 }
@@ -103,65 +102,43 @@ SECTIONS
 		__stop___ex_table = .;
 	} :text = 0x9090
 
-	RODATA
+	RO_DATA(PAGE_SIZE)
 
 	/* Data */
-	. = ALIGN(PAGE_SIZE);
 	.data : AT(ADDR(.data) - LOAD_OFFSET) {
 		/* Start of data section */
 		_sdata = .;
-		DATA_DATA
-		CONSTRUCTORS
-	} :data
+
+		/* init_task */
+		INIT_TASK_DATA(THREAD_SIZE)
 
 #ifdef CONFIG_X86_32
-	/* 32 bit has nosave before _edata */
-	. = ALIGN(PAGE_SIZE);
-	.data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
-		__nosave_begin = .;
-		*(.data.nosave)
-		. = ALIGN(PAGE_SIZE);
-		__nosave_end = .;
-	}
+		/* 32 bit has nosave before _edata */
+		NOSAVE_DATA
 #endif
 
-	. = ALIGN(PAGE_SIZE);
-	.data.page_aligned : AT(ADDR(.data.page_aligned) - LOAD_OFFSET) {
-		*(.data.page_aligned)
+		PAGE_ALIGNED_DATA(PAGE_SIZE)
 		*(.data.idt)
-	}
 
-#ifdef CONFIG_X86_32
-	. = ALIGN(32);
-#else
-	. = ALIGN(PAGE_SIZE);
-	. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
-#endif
-	.data.cacheline_aligned :
-		AT(ADDR(.data.cacheline_aligned) - LOAD_OFFSET) {
-		*(.data.cacheline_aligned)
-	}
+		CACHELINE_ALIGNED_DATA(CONFIG_X86_L1_CACHE_BYTES)
 
-	/* rarely changed data like cpu maps */
-#ifdef CONFIG_X86_32
-	. = ALIGN(32);
-#else
-	. = ALIGN(CONFIG_X86_INTERNODE_CACHE_BYTES);
-#endif
-	.data.read_mostly : AT(ADDR(.data.read_mostly) - LOAD_OFFSET) {
-		*(.data.read_mostly)
+		DATA_DATA
+		CONSTRUCTORS
+
+		/* rarely changed data like cpu maps */
+		READ_MOSTLY_DATA(CONFIG_X86_INTERNODE_CACHE_BYTES)
 
 		/* End of data section */
 		_edata = .;
-	}
+	} :data
 
 #ifdef CONFIG_X86_64
 
 #define VSYSCALL_ADDR (-10*1024*1024)
-#define VSYSCALL_PHYS_ADDR ((LOADADDR(.data.read_mostly) + \
-                            SIZEOF(.data.read_mostly) + 4095) & ~(4095))
-#define VSYSCALL_VIRT_ADDR ((ADDR(.data.read_mostly) + \
-                            SIZEOF(.data.read_mostly) + 4095) & ~(4095))
+#define VSYSCALL_PHYS_ADDR ((LOADADDR(.data) + SIZEOF(.data) + \
+                            PAGE_SIZE - 1) & ~(PAGE_SIZE - 1))
+#define VSYSCALL_VIRT_ADDR ((ADDR(.data) + SIZEOF(.data) + \
+                            PAGE_SIZE - 1) & ~(PAGE_SIZE - 1))
 
 #define VLOAD_OFFSET (VSYSCALL_ADDR - VSYSCALL_PHYS_ADDR)
 #define VLOAD(x) (ADDR(x) - VLOAD_OFFSET)
@@ -227,35 +204,29 @@ SECTIONS
 
 #endif /* CONFIG_X86_64 */
 
-	/* init_task */
-	. = ALIGN(THREAD_SIZE);
-	.data.init_task : AT(ADDR(.data.init_task) - LOAD_OFFSET) {
-		*(.data.init_task)
+	/* Init code and data - will be freed after init */
+	. = ALIGN(PAGE_SIZE);
+	.init.begin : AT(ADDR(.init.begin) - LOAD_OFFSET) {
+		__init_begin = .; /* paired with __init_end */
 	}
-#ifdef CONFIG_X86_64
-	 :data.init
-#endif
 
+#if defined(CONFIG_X86_64) && defined(CONFIG_SMP)
 	/*
-	 * smp_locks might be freed after init
-	 * start/end must be page aligned
+	 * percpu offsets are zero-based on SMP.  PERCPU_VADDR() changes the
+	 * output PHDR, so the next output section - .init.text - should
+	 * start another segment - init.
 	 */
-	. = ALIGN(PAGE_SIZE);
-	.smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
-		__smp_locks = .;
-		*(.smp_locks)
-		__smp_locks_end = .;
-		. = ALIGN(PAGE_SIZE);
-	}
+	PERCPU_VADDR(0, :percpu)
+#endif
 
-	/* Init code and data - will be freed after init */
-	. = ALIGN(PAGE_SIZE);
 	.init.text : AT(ADDR(.init.text) - LOAD_OFFSET) {
-		__init_begin = .; /* paired with __init_end */
 		_sinittext = .;
 		INIT_TEXT
 		_einittext = .;
 	}
+#ifdef CONFIG_X86_64
+	:init
+#endif
 
 	.init.data : AT(ADDR(.init.data) - LOAD_OFFSET) {
 		INIT_DATA
@@ -326,17 +297,7 @@ SECTIONS
 	}
 #endif
 
-#if defined(CONFIG_X86_64) && defined(CONFIG_SMP)
-	/*
-	 * percpu offsets are zero-based on SMP.  PERCPU_VADDR() changes the
-	 * output PHDR, so the next output section - __data_nosave - should
-	 * start another section data.init2.  Also, pda should be at the head of
-	 * percpu area.  Preallocate it and define the percpu offset symbol
-	 * so that it can be accessed as a percpu variable.
-	 */
-	. = ALIGN(PAGE_SIZE);
-	PERCPU_VADDR(0, :percpu)
-#else
+#if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP)
 	PERCPU(PAGE_SIZE)
 #endif
 
@@ -347,15 +308,22 @@ SECTIONS
 		__init_end = .;
 	}
 
+	/*
+	 * smp_locks might be freed after init
+	 * start/end must be page aligned
+	 */
+	. = ALIGN(PAGE_SIZE);
+	.smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
+		__smp_locks = .;
+		*(.smp_locks)
+		__smp_locks_end = .;
+		. = ALIGN(PAGE_SIZE);
+	}
+
 #ifdef CONFIG_X86_64
 	.data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
-		. = ALIGN(PAGE_SIZE);
-		__nosave_begin = .;
-		*(.data.nosave)
-		. = ALIGN(PAGE_SIZE);
-		__nosave_end = .;
-	} :data.init2
-	/* use another section data.init2, see PERCPU_VADDR() above */
+		NOSAVE_DATA
+	}
 #endif
 
 	/* BSS */

Re: [tip:x86/urgent] x86: Fix build with older binutils and consolidate linker script

[Jan Beulich]

>>> Ingo Molnar <mingo@elte.hu> 25.08.09 09:50 >>>
>
>* tip-bot for Jan Beulich <JBeulich@novell.com> wrote:
>
>> Commit-ID:  ddc98b38b6320d5de2e3167673a06ec1a48e9d0e
>> Gitweb:     http://git.kernel.org/tip/ddc98b38b6320d5de2e3167673a06ec1a48e9d0e 
>> Author:     Jan Beulich <JBeulich@novell.com>
>> AuthorDate: Tue, 18 Aug 2009 16:51:27 +0100
>> Committer:  H. Peter Anvin <hpa@zytor.com>
>> CommitDate: Mon, 24 Aug 2009 15:51:35 -0700
>> 
>> x86: Fix build with older binutils and consolidate linker script
>
>this breaks the build with newer binutils:

With the updated patch just submitted I made sure UP and SMP builds
work as well as building with old and current binutils. Sorry for having
forgotten to do so before submitting the first time (I know I had
intended to).

Jan

Re: [tip:x86/urgent] x86: Fix build with older binutils and consolidate linker script

[Ingo Molnar]

* Jan Beulich <JBeulich@novell.com> wrote:

> >>> Ingo Molnar <mingo@elte.hu> 25.08.09 09:50 >>>
> >
> >* tip-bot for Jan Beulich <JBeulich@novell.com> wrote:
> >
> >> Commit-ID:  ddc98b38b6320d5de2e3167673a06ec1a48e9d0e
> >> Gitweb:     http://git.kernel.org/tip/ddc98b38b6320d5de2e3167673a06ec1a48e9d0e 
> >> Author:     Jan Beulich <JBeulich@novell.com>
> >> AuthorDate: Tue, 18 Aug 2009 16:51:27 +0100
> >> Committer:  H. Peter Anvin <hpa@zytor.com>
> >> CommitDate: Mon, 24 Aug 2009 15:51:35 -0700
> >> 
> >> x86: Fix build with older binutils and consolidate linker script
> >
> >this breaks the build with newer binutils:
> 
> With the updated patch just submitted I made sure UP and SMP 
> builds work as well as building with old and current binutils. 

Thanks, applied.

> Sorry for having forgotten to do so before submitting the first 
> time (I know I had intended to).

This happens. I'm still unsure whether we can do it in .31.0 or need 
to delay it to .31.1 via a -stable backport tag. One more problem 
with it and i think we'll need to delay it - it's just too large and 
changes too many aspects of the linker script.

Would it be possible to split it into two pieces: 'minimal fix' and 
'clean up' portions?

	Ingo

[tip:x86/urgent] x86: Fix build with older binutils and consolidate linker script

[tip-bot for Jan Beulich]

Commit-ID:  c62e43202e7cf50ca24bce58b255df7bf5de69d0
Gitweb:     http://git.kernel.org/tip/c62e43202e7cf50ca24bce58b255df7bf5de69d0
Author:     Jan Beulich <JBeulich@novell.com>
AuthorDate: Tue, 25 Aug 2009 14:50:53 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Tue, 25 Aug 2009 15:54:16 +0200

x86: Fix build with older binutils and consolidate linker script

binutils prior to 2.17 can't deal with the currently possible
situation of a new segment following the per-CPU segment, but
that new segment being empty - objcopy misplaces the .bss (and
perhaps also the .brk) sections outside of any segment.

However, the current ordering of sections really just appears
to be the effect of cumulative unrelated changes; re-ordering
things allows to easily guarantee that the segment following
the per-CPU one is non-empty, and at once eliminates the need
for the bogus data.init2 segment.

Once touching this code, also use the various data section
helper macros from include/asm-generic/vmlinux.lds.h.

-v2: fix !SMP builds.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: <sam@ravnborg.org>
LKML-Reference: <4A94085D02000078000119A5@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


---
 arch/x86/kernel/vmlinux.lds.S |  126 +++++++++++++++-------------------------
 1 files changed, 47 insertions(+), 79 deletions(-)

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 78d185d..9fc1782 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -46,11 +46,10 @@ PHDRS {
 	data PT_LOAD FLAGS(7);          /* RWE */
 #ifdef CONFIG_X86_64
 	user PT_LOAD FLAGS(7);          /* RWE */
-	data.init PT_LOAD FLAGS(7);     /* RWE */
 #ifdef CONFIG_SMP
 	percpu PT_LOAD FLAGS(7);        /* RWE */
 #endif
-	data.init2 PT_LOAD FLAGS(7);    /* RWE */
+	init PT_LOAD FLAGS(7);          /* RWE */
 #endif
 	note PT_NOTE FLAGS(0);          /* ___ */
 }
@@ -103,65 +102,43 @@ SECTIONS
 		__stop___ex_table = .;
 	} :text = 0x9090
 
-	RODATA
+	RO_DATA(PAGE_SIZE)
 
 	/* Data */
-	. = ALIGN(PAGE_SIZE);
 	.data : AT(ADDR(.data) - LOAD_OFFSET) {
 		/* Start of data section */
 		_sdata = .;
-		DATA_DATA
-		CONSTRUCTORS
-	} :data
+
+		/* init_task */
+		INIT_TASK_DATA(THREAD_SIZE)
 
 #ifdef CONFIG_X86_32
-	/* 32 bit has nosave before _edata */
-	. = ALIGN(PAGE_SIZE);
-	.data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
-		__nosave_begin = .;
-		*(.data.nosave)
-		. = ALIGN(PAGE_SIZE);
-		__nosave_end = .;
-	}
+		/* 32 bit has nosave before _edata */
+		NOSAVE_DATA
 #endif
 
-	. = ALIGN(PAGE_SIZE);
-	.data.page_aligned : AT(ADDR(.data.page_aligned) - LOAD_OFFSET) {
-		*(.data.page_aligned)
+		PAGE_ALIGNED_DATA(PAGE_SIZE)
 		*(.data.idt)
-	}
 
-#ifdef CONFIG_X86_32
-	. = ALIGN(32);
-#else
-	. = ALIGN(PAGE_SIZE);
-	. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
-#endif
-	.data.cacheline_aligned :
-		AT(ADDR(.data.cacheline_aligned) - LOAD_OFFSET) {
-		*(.data.cacheline_aligned)
-	}
+		CACHELINE_ALIGNED_DATA(CONFIG_X86_L1_CACHE_BYTES)
 
-	/* rarely changed data like cpu maps */
-#ifdef CONFIG_X86_32
-	. = ALIGN(32);
-#else
-	. = ALIGN(CONFIG_X86_INTERNODE_CACHE_BYTES);
-#endif
-	.data.read_mostly : AT(ADDR(.data.read_mostly) - LOAD_OFFSET) {
-		*(.data.read_mostly)
+		DATA_DATA
+		CONSTRUCTORS
+
+		/* rarely changed data like cpu maps */
+		READ_MOSTLY_DATA(CONFIG_X86_INTERNODE_CACHE_BYTES)
 
 		/* End of data section */
 		_edata = .;
-	}
+	} :data
 
 #ifdef CONFIG_X86_64
 
 #define VSYSCALL_ADDR (-10*1024*1024)
-#define VSYSCALL_PHYS_ADDR ((LOADADDR(.data.read_mostly) + \
-                            SIZEOF(.data.read_mostly) + 4095) & ~(4095))
-#define VSYSCALL_VIRT_ADDR ((ADDR(.data.read_mostly) + \
-                            SIZEOF(.data.read_mostly) + 4095) & ~(4095))
+#define VSYSCALL_PHYS_ADDR ((LOADADDR(.data) + SIZEOF(.data) + \
+                            PAGE_SIZE - 1) & ~(PAGE_SIZE - 1))
+#define VSYSCALL_VIRT_ADDR ((ADDR(.data) + SIZEOF(.data) + \
+                            PAGE_SIZE - 1) & ~(PAGE_SIZE - 1))
 
 #define VLOAD_OFFSET (VSYSCALL_ADDR - VSYSCALL_PHYS_ADDR)
 #define VLOAD(x) (ADDR(x) - VLOAD_OFFSET)
@@ -227,35 +204,29 @@ SECTIONS
 
 #endif /* CONFIG_X86_64 */
 
-	/* init_task */
-	. = ALIGN(THREAD_SIZE);
-	.data.init_task : AT(ADDR(.data.init_task) - LOAD_OFFSET) {
-		*(.data.init_task)
+	/* Init code and data - will be freed after init */
+	. = ALIGN(PAGE_SIZE);
+	.init.begin : AT(ADDR(.init.begin) - LOAD_OFFSET) {
+		__init_begin = .; /* paired with __init_end */
 	}
-#ifdef CONFIG_X86_64
-	 :data.init
-#endif
 
+#if defined(CONFIG_X86_64) && defined(CONFIG_SMP)
 	/*
-	 * smp_locks might be freed after init
-	 * start/end must be page aligned
+	 * percpu offsets are zero-based on SMP.  PERCPU_VADDR() changes the
+	 * output PHDR, so the next output section - .init.text - should
+	 * start another segment - init.
 	 */
-	. = ALIGN(PAGE_SIZE);
-	.smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
-		__smp_locks = .;
-		*(.smp_locks)
-		__smp_locks_end = .;
-		. = ALIGN(PAGE_SIZE);
-	}
+	PERCPU_VADDR(0, :percpu)
+#endif
 
-	/* Init code and data - will be freed after init */
-	. = ALIGN(PAGE_SIZE);
 	.init.text : AT(ADDR(.init.text) - LOAD_OFFSET) {
-		__init_begin = .; /* paired with __init_end */
 		_sinittext = .;
 		INIT_TEXT
 		_einittext = .;
 	}
+#ifdef CONFIG_X86_64
+	:init
+#endif
 
 	.init.data : AT(ADDR(.init.data) - LOAD_OFFSET) {
 		INIT_DATA
@@ -326,17 +297,7 @@ SECTIONS
 	}
 #endif
 
-#if defined(CONFIG_X86_64) && defined(CONFIG_SMP)
-	/*
-	 * percpu offsets are zero-based on SMP.  PERCPU_VADDR() changes the
-	 * output PHDR, so the next output section - __data_nosave - should
-	 * start another section data.init2.  Also, pda should be at the head of
-	 * percpu area.  Preallocate it and define the percpu offset symbol
-	 * so that it can be accessed as a percpu variable.
-	 */
-	. = ALIGN(PAGE_SIZE);
-	PERCPU_VADDR(0, :percpu)
-#else
+#if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP)
 	PERCPU(PAGE_SIZE)
 #endif
 
@@ -347,15 +308,22 @@ SECTIONS
 		__init_end = .;
 	}
 
+	/*
+	 * smp_locks might be freed after init
+	 * start/end must be page aligned
+	 */
+	. = ALIGN(PAGE_SIZE);
+	.smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
+		__smp_locks = .;
+		*(.smp_locks)
+		__smp_locks_end = .;
+		. = ALIGN(PAGE_SIZE);
+	}
+
 #ifdef CONFIG_X86_64
 	.data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
-		. = ALIGN(PAGE_SIZE);
-		__nosave_begin = .;
-		*(.data.nosave)
-		. = ALIGN(PAGE_SIZE);
-		__nosave_end = .;
-	} :data.init2
-	/* use another section data.init2, see PERCPU_VADDR() above */
+		NOSAVE_DATA
+	}
 #endif
 
 	/* BSS */