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: Michael Ellerman <m...@ellerman.id.au>
---
arch/powerpc/kernel/Makefile | 3 ++-
arch/powerpc/kernel/signal_32.c | 11 ++++++++--
arch/powerpc/kernel/vdso.c | 38 +++++++++++++++++++++++++++++++++-
arch/powerpc/perf/callchain.c | 5 +++++
arch/powerpc/platforms/Kconfig.cputype | 10 +++++++++
5 files changed, 63 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index c1ebbdaac28f..87c7d1473488 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -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
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index d3a831ac0f92..561df3c153cc 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -1011,10 +1011,14 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t
*oldset,
/* Save user registers on the stack */
frame = &rt_sf->uc.uc_mcontext;
addr = frame;
+
+#ifdef CONFIG_VDSO32
if (vdso32_rt_sigtramp && current->mm->context.vdso_base) {
sigret = 0;
tramp = current->mm->context.vdso_base + vdso32_rt_sigtramp;
- } else {
+ } else
+#endif
+ {
sigret = __NR_rt_sigreturn;
tramp = (unsigned long) frame->tramp;
}
@@ -1436,10 +1440,13 @@ int handle_signal32(struct ksignal *ksig, sigset_t
*oldset, struct pt_regs *regs
|| __put_user(ksig->sig, &sc->signal))
goto badframe;
+#ifdef CONFIG_VDSO32
if (vdso32_sigtramp && current->mm->context.vdso_base) {
sigret = 0;
tramp = current->mm->context.vdso_base + vdso32_sigtramp;
- } else {
+ } else
+#endif
+ {
sigret = __NR_sigreturn;
tramp = (unsigned long) frame->mctx.tramp;
}
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index 305eb0d9b768..3cdf4e87917d 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -49,12 +49,14 @@
/* The alignment of the vDSO */
#define VDSO_ALIGNMENT (1 << 16)
+#ifdef CONFIG_VDSO32
extern char vdso32_start, vdso32_end;
static void *vdso32_kbase = &vdso32_start;
static unsigned int vdso32_pages;
static struct page **vdso32_pagelist;
unsigned long vdso32_sigtramp;
unsigned long vdso32_rt_sigtramp;
+#endif
#ifdef CONFIG_PPC64
extern char vdso64_start, vdso64_end;
@@ -159,6 +161,7 @@ static void dump_vdso_pages(struct vm_area_struct * vma)
{
int i;
+#ifdef CONFIG_VDSO32
if (!vma || is_32bit_task()) {
printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
for (i=0; i<vdso32_pages; i++) {
@@ -170,6 +173,8 @@ static void dump_vdso_pages(struct vm_area_struct * vma)
dump_one_vdso_page(pg, upg);
}
}
+#endif
+
if (!vma || !is_32bit_task()) {
printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
for (i=0; i<vdso64_pages; i++) {
@@ -200,11 +205,14 @@ int arch_setup_additional_pages(struct linux_binprm
*bprm, int uses_interp)
return 0;
#ifdef CONFIG_PPC64
+#ifdef CONFIG_VDSO32
if (is_32bit_task()) {
vdso_pagelist = vdso32_pagelist;
vdso_pages = vdso32_pages;
vdso_base = VDSO32_MBASE;
- } else {
+ } else
+#endif
+ {
vdso_pagelist = vdso64_pagelist;
vdso_pages = vdso64_pages;
/*
@@ -292,6 +300,7 @@ 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)
{
@@ -314,7 +323,9 @@ static void * __init find_section32(Elf32_Ehdr *ehdr, const
char *secname,
*size = 0;
return NULL;
}
+#endif
+#ifdef CONFIG_VDSO32
static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
const char *symname)
{
@@ -334,7 +345,9 @@ static Elf32_Sym * __init find_symbol32(struct
lib32_elfinfo *lib,
}
return NULL;
}
+#endif
+#ifdef CONFIG_VDSO32
/* Note that we assume the section is .text and the symbol is relative to
* the library base
*/
@@ -379,6 +392,7 @@ static int __init vdso_do_func_patch32(struct lib32_elfinfo
*v32,
return 0;
}
+#endif
#ifdef CONFIG_PPC64
@@ -489,6 +503,7 @@ 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) {
@@ -501,6 +516,7 @@ 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);
@@ -530,14 +546,18 @@ static __init void vdso_setup_trampolines(struct
lib32_elfinfo *v32,
#ifdef CONFIG_PPC64
vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
#endif
+#ifdef CONFIG_VDSO32
vdso32_sigtramp = find_function32(v32, "__kernel_sigtramp32");
vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
+#endif
}
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;
@@ -552,6 +572,7 @@ 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 "
@@ -561,6 +582,7 @@ 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;
}
@@ -569,8 +591,10 @@ static __init int vdso_fixup_datapage(struct lib32_elfinfo
*v32,
static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
struct lib64_elfinfo *v64)
{
+#ifdef CONFIG_VDSO32
void *start32;
unsigned long size32;
+#endif
#ifdef CONFIG_PPC64
void *start64;
@@ -597,6 +621,7 @@ static __init int vdso_fixup_features(struct lib32_elfinfo
*v32,
start64, start64 + size64);
#endif /* CONFIG_PPC64 */
+#ifdef CONFIG_VDSO32
start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
if (start32)
do_feature_fixups(cur_cpu_spec->cpu_features,
@@ -618,6 +643,7 @@ static __init int vdso_fixup_features(struct lib32_elfinfo
*v32,
if (start32)
do_lwsync_fixups(cur_cpu_spec->cpu_features,
start32, start32 + size32);
+#endif
return 0;
}
@@ -643,8 +669,10 @@ static __init int vdso_fixup_alt_funcs(struct
lib32_elfinfo *v32,
* It would be easy to do, but doesn't seem to be necessary,
* patching the OPD symbol is enough.
*/
+#ifdef CONFIG_VDSO32
vdso_do_func_patch32(v32, v64, patch->gen_name,
patch->fix_name);
+#endif
#ifdef CONFIG_PPC64
vdso_do_func_patch64(v32, v64, patch->gen_name,
patch->fix_name);
@@ -660,7 +688,9 @@ static __init int vdso_setup(void)
struct lib32_elfinfo v32;
struct lib64_elfinfo v64;
+#ifdef CONFIG_VDSO32
v32.hdr = vdso32_kbase;
+#endif
#ifdef CONFIG_PPC64
v64.hdr = vdso64_kbase;
#endif
@@ -779,11 +809,13 @@ static int __init vdso_init(void)
#endif /* CONFIG_PPC64 */
+#ifdef CONFIG_VDSO32
/*
* 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
/*
@@ -797,13 +829,16 @@ static int __init vdso_init(void)
*/
if (vdso_setup()) {
printk(KERN_ERR "vDSO setup failure, not enabled !\n");
+#ifdef CONFIG_VDSO32
vdso32_pages = 0;
+#endif
#ifdef CONFIG_PPC64
vdso64_pages = 0;
#endif
return 0;
}
+#ifdef CONFIG_VDSO32
/* Make sure pages are in the correct state */
vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),
GFP_KERNEL);
@@ -816,6 +851,7 @@ 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),
diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c
index ead55351b254..4ebb6640b23f 100644
--- a/arch/powerpc/perf/callchain.c
+++ b/arch/powerpc/perf/callchain.c
@@ -364,9 +364,11 @@ static int is_sigreturn_32_address(unsigned int nip,
unsigned int fp)
{
if (nip == fp + offsetof(struct signal_frame_32, mctx.mc_pad))
return 1;
+#ifdef CONFIG_VDSO32
if (vdso32_sigtramp && current->mm->context.vdso_base &&
nip == current->mm->context.vdso_base + vdso32_sigtramp)
return 1;
+#endif
return 0;
}
@@ -375,9 +377,12 @@ static int is_rt_sigreturn_32_address(unsigned int nip,
unsigned int fp)
if (nip == fp + offsetof(struct rt_signal_frame_32,
uc.uc_mcontext.mc_pad))
return 1;
+
+#ifdef CONFIG_VDSO32
if (vdso32_rt_sigtramp && current->mm->context.vdso_base &&
nip == current->mm->context.vdso_base + vdso32_rt_sigtramp)
return 1;
+#endif
return 0;
}
diff --git a/arch/powerpc/platforms/Kconfig.cputype
b/arch/powerpc/platforms/Kconfig.cputype
index 12fc443b9d54..1324f589f43a 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -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
--
2.1.0
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