Commit e0d00591 authored by Michael Ellerman's avatar Michael Ellerman
Browse files

powerpc/vdso: Disable building the 32-bit VDSO on little endian 



The only little endian configuration we support is ppc64le. As such if
we're building little endian we don't need a 32-bit VDSO, because there
is no 32-bit userspace.

This patch is a fairly ugly mess of #ifdefs, but is the minimal logic
required to disable the 32-bit VDSO. We can hopefully clean up the
result in future with some further refactoring.

Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 6e5c0775

arch/powerpc/kernel/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -33,11 +33,12 @@ obj-y := cputable.o ptrace.o syscalls.o \ 
				   signal.o sysfs.o cacheinfo.o time.o \

				   prom.o traps.o setup-common.o \

				   udbg.o misc.o io.o dma.o \

				   misc_$(CONFIG_WORD_SIZE).o vdso32/ \

				   misc_$(CONFIG_WORD_SIZE).o \

				   of_platform.o prom_parse.o

obj-$(CONFIG_PPC64)		+= setup_64.o sys_ppc32.o \

				   signal_64.o ptrace32.o \

				   paca.o nvram_64.o firmware.o

obj-$(CONFIG_VDSO32)		+= vdso32/

obj-$(CONFIG_HAVE_HW_BREAKPOINT)	+= hw_breakpoint.o

obj-$(CONFIG_PPC_BOOK3S_64)	+= cpu_setup_ppc970.o cpu_setup_pa6t.o

obj-$(CONFIG_PPC_BOOK3S_64)	+= cpu_setup_power.o

arch/powerpc/kernel/vdso.c

+34 −2
Original line number Diff line number Diff line
@@ -49,13 +49,16 @@ 
/* The alignment of the vDSO */

#define VDSO_ALIGNMENT	(1 << 16)



extern char vdso32_start, vdso32_end;

static void *vdso32_kbase = &vdso32_start;

static unsigned int vdso32_pages;

static void *vdso32_kbase;

static struct page **vdso32_pagelist;

unsigned long vdso32_sigtramp;

unsigned long vdso32_rt_sigtramp;



#ifdef CONFIG_VDSO32

extern char vdso32_start, vdso32_end;

#endif



#ifdef CONFIG_PPC64

extern char vdso64_start, vdso64_end;

static void *vdso64_kbase = &vdso64_start;
@@ -248,6 +251,7 @@ const char *arch_vma_name(struct vm_area_struct *vma) 






#ifdef CONFIG_VDSO32

static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,

				  unsigned long *size)

{
@@ -335,6 +339,20 @@ static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32, 


	return 0;

}

#else /* !CONFIG_VDSO32 */

static unsigned long __init find_function32(struct lib32_elfinfo *lib,

					    const char *symname)

{

	return 0;

}



static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,

				       struct lib64_elfinfo *v64,

				       const char *orig, const char *fix)

{

	return 0;

}

#endif /* CONFIG_VDSO32 */





#ifdef CONFIG_PPC64
@@ -445,6 +463,7 @@ static __init int vdso_do_find_sections(struct lib32_elfinfo *v32, 
	 * Locate symbol tables & text section

	 */



#ifdef CONFIG_VDSO32

	v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);

	v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);

	if (v32->dynsym == NULL || v32->dynstr == NULL) {
@@ -457,6 +476,7 @@ static __init int vdso_do_find_sections(struct lib32_elfinfo *v32, 
		return -1;

	}

	v32->text = sect - vdso32_kbase;

#endif



#ifdef CONFIG_PPC64

	v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
@@ -493,7 +513,9 @@ static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32, 
static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,

				       struct lib64_elfinfo *v64)

{

#ifdef CONFIG_VDSO32

	Elf32_Sym *sym32;

#endif

#ifdef CONFIG_PPC64

	Elf64_Sym *sym64;
@@ -508,6 +530,7 @@ static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32, 
		(sym64->st_value - VDSO64_LBASE);

#endif /* CONFIG_PPC64 */



#ifdef CONFIG_VDSO32

	sym32 = find_symbol32(v32, "__kernel_datapage_offset");

	if (sym32 == NULL) {

		printk(KERN_ERR "vDSO32: Can't find symbol "
@@ -517,6 +540,7 @@ static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32, 
	*((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =

		(vdso32_pages << PAGE_SHIFT) -

		(sym32->st_value - VDSO32_LBASE);

#endif



	return 0;

}
@@ -550,6 +574,7 @@ static __init int vdso_fixup_features(struct lib32_elfinfo *v32, 
				 start, start + size);

#endif /* CONFIG_PPC64 */



#ifdef CONFIG_VDSO32

	start = find_section32(v32->hdr, "__ftr_fixup", &size);

	if (start)

		do_feature_fixups(cur_cpu_spec->cpu_features,
@@ -571,6 +596,7 @@ static __init int vdso_fixup_features(struct lib32_elfinfo *v32, 
	if (start)

		do_lwsync_fixups(cur_cpu_spec->cpu_features,

				 start, start + size);

#endif



	return 0;

}
@@ -732,11 +758,15 @@ static int __init vdso_init(void) 
#endif /* CONFIG_PPC64 */





#ifdef CONFIG_VDSO32

	vdso32_kbase = &vdso32_start;



	/*

	 * Calculate the size of the 32 bits vDSO

	 */

	vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;

	DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);

#endif





	/*
@@ -757,6 +787,7 @@ static int __init vdso_init(void) 
		return 0;

	}



#ifdef CONFIG_VDSO32

	/* Make sure pages are in the correct state */

	vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),

				  GFP_KERNEL);
@@ -769,6 +800,7 @@ static int __init vdso_init(void) 
	}

	vdso32_pagelist[i++] = virt_to_page(vdso_data);

	vdso32_pagelist[i] = NULL;

#endif



#ifdef CONFIG_PPC64

	vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 2),

arch/powerpc/platforms/Kconfig.cputype

+10 −0
Original line number Diff line number Diff line
@@ -405,6 +405,16 @@ config PPC_DOORBELL 


endmenu



config VDSO32

	def_bool y

	depends on PPC32 || CPU_BIG_ENDIAN

	help

	  This symbol controls whether we build the 32-bit VDSO. We obviously

	  want to do that if we're building a 32-bit kernel. If we're building

	  a 64-bit kernel then we only want a 32-bit VDSO if we're building for

	  big endian. That is because the only little endian configuration we

	  support is ppc64le which is 64-bit only.



choice

	prompt "Endianness selection"

	default CPU_BIG_ENDIAN

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