| Message ID | 1409779158-30963-19-git-send-email-apinski@cavium.com |
|---|---|
| State | New |
| Headers | show |
Hi Andrew, On 09/03/2014 05:19 PM, Andrew Pinski wrote: > This patch adds the VDSO for ILP32. We need to use a different > VDSO than LP64 since ILP32 uses ELF32 while LP64 uses ELF64. > > After this patch, signal handling works mostly. In that signals > go through their action and then returned correctly. > > Signed-off-by: Andrew Pinski <apinski@cavium.com> > --- > arch/arm64/include/asm/vdso.h | 4 + > arch/arm64/kernel/Makefile | 5 + > arch/arm64/kernel/signal.c | 4 + > arch/arm64/kernel/vdso-ilp32/.gitignore | 2 + > arch/arm64/kernel/vdso-ilp32/Makefile | 72 ++++++++++++++++++ > arch/arm64/kernel/vdso-ilp32/vdso-ilp32.S | 33 ++++++++ > arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S | 98 +++++++++++++++++++++++++ > arch/arm64/kernel/vdso.c | 69 ++++++++++++++--- > 8 files changed, 274 insertions(+), 13 deletions(-) > create mode 100644 arch/arm64/kernel/vdso-ilp32/.gitignore > create mode 100644 arch/arm64/kernel/vdso-ilp32/Makefile > create mode 100644 arch/arm64/kernel/vdso-ilp32/vdso-ilp32.S > create mode 100644 arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S > > diff --git a/arch/arm64/include/asm/vdso.h b/arch/arm64/include/asm/vdso.h > index 839ce00..84050c6 100644 > --- a/arch/arm64/include/asm/vdso.h > +++ b/arch/arm64/include/asm/vdso.h > @@ -29,6 +29,10 @@ > > #include <generated/vdso-offsets.h> > > +#ifdef CONFIG_ARM64_ILP32 > +#include <generated/vdso-ilp32-offsets.h> > +#endif > + > #define VDSO_SYMBOL(base, name) \ > ({ \ > (void *)(vdso_offset_##name - VDSO_LBASE + (unsigned long)(base)); \ > diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile > index 6de85f5..dcb9033 100644 > --- a/arch/arm64/kernel/Makefile > +++ b/arch/arm64/kernel/Makefile > @@ -31,6 +31,7 @@ arm64-obj-$(CONFIG_KGDB) += kgdb.o > arm64-obj-$(CONFIG_EFI) += efi.o efi-stub.o efi-entry.o > > obj-y += $(arm64-obj-y) vdso/ > +obj-$(CONFIG_ARM64_ILP32) += vdso-ilp32/ > obj-m += $(arm64-obj-m) > head-y := head.o > extra-y := $(head-y) vmlinux.lds > @@ -38,3 +39,7 @@ extra-y := $(head-y) vmlinux.lds > # vDSO - this must be built first to generate the symbol offsets > $(call objectify,$(arm64-obj-y)): $(obj)/vdso/vdso-offsets.h > $(obj)/vdso/vdso-offsets.h: $(obj)/vdso > + > +# vDSO - this must be built first to generate the symbol offsets > +$(call objectify,$(arm64-obj-y)): $(obj)/vdso-ilp32/vdso-ilp32-offsets.h > +$(obj)/vdso-ilp32/vdso-ilp32-offsets.h: $(obj)/vdso-ilp32 > diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c > index f47c064..5311147 100644 > --- a/arch/arm64/kernel/signal.c > +++ b/arch/arm64/kernel/signal.c > @@ -242,6 +242,10 @@ static void setup_return(struct pt_regs *regs, struct k_sigaction *ka, > > if (ka->sa.sa_flags & SA_RESTORER) > sigtramp = ka->sa.sa_restorer; > +#ifdef CONFIG_ARM64_ILP32 > + else if (is_ilp32_compat_task()) > + sigtramp = VDSO_SYMBOL(current->mm->context.vdso, sigtramp_ilp32); > +#endif > else > sigtramp = VDSO_SYMBOL(current->mm->context.vdso, sigtramp); In my opinion, moving the ifdef around the definition of is_ilp32_compat_task() would make the code easier to read and maintain. > diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c > index a777ac3..21b3726 100644 > --- a/arch/arm64/kernel/vdso.c > +++ b/arch/arm64/kernel/vdso.c > @@ -41,6 +41,12 @@ extern char vdso_start, vdso_end; > static unsigned long vdso_pages; > static struct page **vdso_pagelist; > > +#ifdef CONFIG_ARM64_ILP32 > +extern char vdso_ilp32_start, vdso_ilp32_end; > +static unsigned long vdso_ilp32_pages; > +static struct page **vdso_ilp32_pagelist; > +#endif > + > /* > * The vDSO data page. > */ > @@ -110,24 +116,31 @@ int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp) > } > #endif /* CONFIG_AARCH32_EL0 */ > > -static struct vm_special_mapping vdso_spec[2]; > +static struct vm_special_mapping vdso_spec[2][2]; > > -static int __init vdso_init(void) > +static inline int __init vdso_init_common(char *vdso_start, char *vdso_end, > + unsigned long *vdso_pagesp, > + struct page ***vdso_pagelistp, > + bool ilp32) > { > int i; > + unsigned long vdso_pages; > + struct page **vdso_pagelist; > > - if (memcmp(&vdso_start, "\177ELF", 4)) { > + if (memcmp(vdso_start, "\177ELF", 4)) { > pr_err("vDSO is not a valid ELF object!\n"); > return -EINVAL; > } > > - vdso_pages = (&vdso_end - &vdso_start) >> PAGE_SHIFT; > + vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT; > + *vdso_pagesp = vdso_pages; > pr_info("vdso: %ld pages (%ld code @ %p, %ld data @ %p)\n", > - vdso_pages + 1, vdso_pages, &vdso_start, 1L, vdso_data); > + vdso_pages + 1, vdso_pages, vdso_start, 1L, vdso_data); > > /* Allocate the vDSO pagelist, plus a page for the data. */ > vdso_pagelist = kcalloc(vdso_pages + 1, sizeof(struct page *), > GFP_KERNEL); > + *vdso_pagelistp = vdso_pagelist; > if (vdso_pagelist == NULL) > return -ENOMEM; > > @@ -136,33 +149,63 @@ static int __init vdso_init(void) > > /* Grab the vDSO code pages. */ > for (i = 0; i < vdso_pages; i++) > - vdso_pagelist[i + 1] = virt_to_page(&vdso_start + i * PAGE_SIZE); > + vdso_pagelist[i + 1] = virt_to_page(vdso_start + i * PAGE_SIZE); > > /* Populate the special mapping structures */ > - vdso_spec[0] = (struct vm_special_mapping) { > + vdso_spec[ilp32][0] = (struct vm_special_mapping) { > .name = "[vvar]", > .pages = vdso_pagelist, > }; > > - vdso_spec[1] = (struct vm_special_mapping) { > + vdso_spec[ilp32][1] = (struct vm_special_mapping) { > .name = "[vdso]", > .pages = &vdso_pagelist[1], > }; > > return 0; > } > + > +static int __init vdso_init(void) > +{ > + return vdso_init_common(&vdso_start, &vdso_end, > + &vdso_pages, &vdso_pagelist, 0); > +} > arch_initcall(vdso_init); > > +#ifdef CONFIG_ARM64_ILP32 > +static int __init vdso_ilp32_init(void) > +{ > + return vdso_init_common(&vdso_ilp32_start, &vdso_ilp32_end, > + &vdso_ilp32_pages, &vdso_ilp32_pagelist, 1); > +} > +arch_initcall(vdso_ilp32_init); > +#endif > + > int arch_setup_additional_pages(struct linux_binprm *bprm, > int uses_interp) > { > struct mm_struct *mm = current->mm; > unsigned long vdso_base, vdso_text_len, vdso_mapping_len; > void *ret; > - > - vdso_text_len = vdso_pages << PAGE_SHIFT; > + struct page **pagelist; > + unsigned long pages; > + bool ilp32; > + > +#ifdef CONFIG_ARM64_ILP32 > + ilp32 = is_ilp32_compat_task(); > + if (is_ilp32_compat_task()) { > + pages = vdso_ilp32_pages; > + pagelist = vdso_ilp32_pagelist; > + } else > +#endif Same > + { > + ilp32 = false; > + pages = vdso_pages; > + pagelist = vdso_pagelist; > + } > + vdso_text_len = pages << PAGE_SHIFT; > /* Be sure to map the data page */ > - vdso_mapping_len = vdso_text_len + PAGE_SIZE; > + vdso_mapping_len = (pages + 1) << PAGE_SHIFT; > > down_write(&mm->mmap_sem); > vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0); > @@ -172,7 +215,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, > } > ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE, > VM_READ|VM_MAYREAD, > - &vdso_spec[0]); > + &vdso_spec[ilp32][0]); > if (IS_ERR(ret)) > goto up_fail; > > @@ -181,7 +224,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, > ret = _install_special_mapping(mm, vdso_base, vdso_text_len, > VM_READ|VM_EXEC| > VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, > - &vdso_spec[1]); > + &vdso_spec[ilp32][1]); > if (IS_ERR(ret)) > goto up_fail; > > Regards, Christopher
On Wed, Sep 03, 2014 at 10:19:12PM +0100, Andrew Pinski wrote: > This patch adds the VDSO for ILP32. We need to use a different > VDSO than LP64 since ILP32 uses ELF32 while LP64 uses ELF64. > > After this patch, signal handling works mostly. In that signals > go through their action and then returned correctly. As you say "mostly", is there anything that does not work?
On Wed, Sep 03, 2014 at 10:19:12PM +0100, Andrew Pinski wrote: > diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c > index f47c064..5311147 100644 > --- a/arch/arm64/kernel/signal.c > +++ b/arch/arm64/kernel/signal.c > @@ -242,6 +242,10 @@ static void setup_return(struct pt_regs *regs, struct k_sigaction *ka, > > if (ka->sa.sa_flags & SA_RESTORER) > sigtramp = ka->sa.sa_restorer; > +#ifdef CONFIG_ARM64_ILP32 > + else if (is_ilp32_compat_task()) > + sigtramp = VDSO_SYMBOL(current->mm->context.vdso, sigtramp_ilp32); > +#endif Could we avoid the #ifdef here given that is_ilp32_compat_task() returns 0 when !CONFIG_ARM64_ILP32? I haven't tried to compile it. > diff --git a/arch/arm64/kernel/vdso-ilp32/Makefile b/arch/arm64/kernel/vdso-ilp32/Makefile > new file mode 100644 > index 0000000..c8f5472 > --- /dev/null > +++ b/arch/arm64/kernel/vdso-ilp32/Makefile Do we expect so many ILP32 files as to use a separate vdso-ilp32 directory? I prefer a single vdso directory. > @@ -0,0 +1,72 @@ > +# > +# Building a vDSO image for AArch64. > +# > +# Author: Will Deacon <will.deacon@arm.com> > +# Heavily based on the vDSO Makefiles for other archs. > +# > + > +obj-ilp32-vdso := gettimeofday-ilp32.o note-ilp32.o sigreturn-ilp32.o > + > +# Build rules > +targets := $(obj-ilp32-vdso) vdso-ilp32.so vdso-ilp32.so.dbg > +obj-ilp32-vdso := $(addprefix $(obj)/, $(obj-ilp32-vdso)) > + > +ccflags-y := -shared -fno-common -fno-builtin > +ccflags-y += -nostdlib -Wl,-soname=linux-ilp32-vdso.so.1 \ > + $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) > + > +obj-y += vdso-ilp32.o > +extra-y += vdso-ilp32.lds vdso-ilp32-offsets.h > +CPPFLAGS_vdso-ilp32.lds += -P -C -U$(ARCH) -mabi=ilp32 > + > +# Force dependency (incbin is bad) > +$(obj)/vdso-ilp32.o : $(obj)/vdso-ilp32.so > + > +# Link rule for the .so file, .lds has to be first > +$(obj)/vdso-ilp32.so.dbg: $(src)/vdso-ilp32.lds $(obj-ilp32-vdso) > + $(call if_changed,vdso-ilp32ld) > + > +# Strip rule for the .so file > +$(obj)/%.so: OBJCOPYFLAGS := -S > +$(obj)/%.so: $(obj)/%.so.dbg FORCE > + $(call if_changed,objcopy) > + > +# Generate VDSO offsets using helper script > +gen-vdsosym := $(srctree)/$(src)/../vdso/gen_vdso_offsets.sh > +quiet_cmd_vdsosym = VDSOSYM $@ > +define cmd_vdsosym > + $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ && \ > + cp $@ include/generated/ > +endef > + > +$(obj)/vdso-ilp32-offsets.h: $(obj)/vdso-ilp32.so.dbg FORCE > + $(call if_changed,vdsosym) > + > +# Assembly rules for the .S files > +#$(obj-ilp32-vdso): %.o: $(src)/../vdso/$(subst -ilp32,,%.S) > +# $(call if_changed_dep,vdso-ilp32as) > + > +$(obj)/gettimeofday-ilp32.o: $(src)/../vdso/gettimeofday.S > + $(call if_changed_dep,vdso-ilp32as) > + > +$(obj)/note-ilp32.o: $(src)/../vdso/note.S > + $(call if_changed_dep,vdso-ilp32as) > + > +$(obj)/sigreturn-ilp32.o: $(src)/../vdso/sigreturn.S > + $(call if_changed_dep,vdso-ilp32as) So we don't even need many new files, just different compiler flags. > diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c > index a777ac3..21b3726 100644 > --- a/arch/arm64/kernel/vdso.c > +++ b/arch/arm64/kernel/vdso.c > @@ -41,6 +41,12 @@ extern char vdso_start, vdso_end; > static unsigned long vdso_pages; > static struct page **vdso_pagelist; > > +#ifdef CONFIG_ARM64_ILP32 > +extern char vdso_ilp32_start, vdso_ilp32_end; > +static unsigned long vdso_ilp32_pages; > +static struct page **vdso_ilp32_pagelist; > +#endif I think the compiler could optimise away some of these and avoid the #ifdef (similarly in the code where we check for is_ilp32_compat_task()).
diff --git a/arch/arm64/include/asm/vdso.h b/arch/arm64/include/asm/vdso.h index 839ce00..84050c6 100644 --- a/arch/arm64/include/asm/vdso.h +++ b/arch/arm64/include/asm/vdso.h @@ -29,6 +29,10 @@ #include <generated/vdso-offsets.h> +#ifdef CONFIG_ARM64_ILP32 +#include <generated/vdso-ilp32-offsets.h> +#endif + #define VDSO_SYMBOL(base, name) \ ({ \ (void *)(vdso_offset_##name - VDSO_LBASE + (unsigned long)(base)); \ diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 6de85f5..dcb9033 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -31,6 +31,7 @@ arm64-obj-$(CONFIG_KGDB) += kgdb.o arm64-obj-$(CONFIG_EFI) += efi.o efi-stub.o efi-entry.o obj-y += $(arm64-obj-y) vdso/ +obj-$(CONFIG_ARM64_ILP32) += vdso-ilp32/ obj-m += $(arm64-obj-m) head-y := head.o extra-y := $(head-y) vmlinux.lds @@ -38,3 +39,7 @@ extra-y := $(head-y) vmlinux.lds # vDSO - this must be built first to generate the symbol offsets $(call objectify,$(arm64-obj-y)): $(obj)/vdso/vdso-offsets.h $(obj)/vdso/vdso-offsets.h: $(obj)/vdso + +# vDSO - this must be built first to generate the symbol offsets +$(call objectify,$(arm64-obj-y)): $(obj)/vdso-ilp32/vdso-ilp32-offsets.h +$(obj)/vdso-ilp32/vdso-ilp32-offsets.h: $(obj)/vdso-ilp32 diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index f47c064..5311147 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -242,6 +242,10 @@ static void setup_return(struct pt_regs *regs, struct k_sigaction *ka, if (ka->sa.sa_flags & SA_RESTORER) sigtramp = ka->sa.sa_restorer; +#ifdef CONFIG_ARM64_ILP32 + else if (is_ilp32_compat_task()) + sigtramp = VDSO_SYMBOL(current->mm->context.vdso, sigtramp_ilp32); +#endif else sigtramp = VDSO_SYMBOL(current->mm->context.vdso, sigtramp); diff --git a/arch/arm64/kernel/vdso-ilp32/.gitignore b/arch/arm64/kernel/vdso-ilp32/.gitignore new file mode 100644 index 0000000..61806c3 --- /dev/null +++ b/arch/arm64/kernel/vdso-ilp32/.gitignore @@ -0,0 +1,2 @@ +vdso-ilp32.lds +vdso-ilp32-offsets.h diff --git a/arch/arm64/kernel/vdso-ilp32/Makefile b/arch/arm64/kernel/vdso-ilp32/Makefile new file mode 100644 index 0000000..c8f5472 --- /dev/null +++ b/arch/arm64/kernel/vdso-ilp32/Makefile @@ -0,0 +1,72 @@ +# +# Building a vDSO image for AArch64. +# +# Author: Will Deacon <will.deacon@arm.com> +# Heavily based on the vDSO Makefiles for other archs. +# + +obj-ilp32-vdso := gettimeofday-ilp32.o note-ilp32.o sigreturn-ilp32.o + +# Build rules +targets := $(obj-ilp32-vdso) vdso-ilp32.so vdso-ilp32.so.dbg +obj-ilp32-vdso := $(addprefix $(obj)/, $(obj-ilp32-vdso)) + +ccflags-y := -shared -fno-common -fno-builtin +ccflags-y += -nostdlib -Wl,-soname=linux-ilp32-vdso.so.1 \ + $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) + +obj-y += vdso-ilp32.o +extra-y += vdso-ilp32.lds vdso-ilp32-offsets.h +CPPFLAGS_vdso-ilp32.lds += -P -C -U$(ARCH) -mabi=ilp32 + +# Force dependency (incbin is bad) +$(obj)/vdso-ilp32.o : $(obj)/vdso-ilp32.so + +# Link rule for the .so file, .lds has to be first +$(obj)/vdso-ilp32.so.dbg: $(src)/vdso-ilp32.lds $(obj-ilp32-vdso) + $(call if_changed,vdso-ilp32ld) + +# Strip rule for the .so file +$(obj)/%.so: OBJCOPYFLAGS := -S +$(obj)/%.so: $(obj)/%.so.dbg FORCE + $(call if_changed,objcopy) + +# Generate VDSO offsets using helper script +gen-vdsosym := $(srctree)/$(src)/../vdso/gen_vdso_offsets.sh +quiet_cmd_vdsosym = VDSOSYM $@ +define cmd_vdsosym + $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ && \ + cp $@ include/generated/ +endef + +$(obj)/vdso-ilp32-offsets.h: $(obj)/vdso-ilp32.so.dbg FORCE + $(call if_changed,vdsosym) + +# Assembly rules for the .S files +#$(obj-ilp32-vdso): %.o: $(src)/../vdso/$(subst -ilp32,,%.S) +# $(call if_changed_dep,vdso-ilp32as) + +$(obj)/gettimeofday-ilp32.o: $(src)/../vdso/gettimeofday.S + $(call if_changed_dep,vdso-ilp32as) + +$(obj)/note-ilp32.o: $(src)/../vdso/note.S + $(call if_changed_dep,vdso-ilp32as) + +$(obj)/sigreturn-ilp32.o: $(src)/../vdso/sigreturn.S + $(call if_changed_dep,vdso-ilp32as) + +# Actual build commands +quiet_cmd_vdso-ilp32ld = VDSOILP32L $@ + cmd_vdso-ilp32ld = $(CC) $(c_flags) -mabi=ilp32 -Wl,-n -Wl,-T $^ -o $@ +quiet_cmd_vdso-ilp32as = VDSOILP32A $@ + cmd_vdso-ilp32as = $(CC) $(a_flags) -mabi=ilp32 -c -o $@ $< + +# Install commands for the unstripped file +quiet_cmd_vdso_install = INSTALL $@ + cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@ + +vdso-ilp32.so: $(obj)/vdso-ilp32.so.dbg + @mkdir -p $(MODLIB)/vdso + $(call cmd,vdso_install) + +vdso_install: vdso-ilp32.so diff --git a/arch/arm64/kernel/vdso-ilp32/vdso-ilp32.S b/arch/arm64/kernel/vdso-ilp32/vdso-ilp32.S new file mode 100644 index 0000000..46ac072 --- /dev/null +++ b/arch/arm64/kernel/vdso-ilp32/vdso-ilp32.S @@ -0,0 +1,33 @@ +/* + * Copyright (C) 2012 ARM Limited + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * Author: Will Deacon <will.deacon@arm.com> + */ + +#include <linux/init.h> +#include <linux/linkage.h> +#include <linux/const.h> +#include <asm/page.h> + + __PAGE_ALIGNED_DATA + + .globl vdso_ilp32_start, vdso_ilp32_end + .balign PAGE_SIZE +vdso_ilp32_start: + .incbin "arch/arm64/kernel/vdso-ilp32/vdso-ilp32.so" + .balign PAGE_SIZE +vdso_ilp32_end: + + .previous diff --git a/arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S b/arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S new file mode 100644 index 0000000..ac8029b --- /dev/null +++ b/arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S @@ -0,0 +1,98 @@ +/* + * GNU linker script for the VDSO library. + * + * Copyright (C) 2012 ARM Limited + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * Author: Will Deacon <will.deacon@arm.com> + * Heavily based on the vDSO linker scripts for other archs. + */ + +#include <linux/const.h> +#include <asm/page.h> +#include <asm/vdso.h> + +/*OUTPUT_FORMAT("elf32-littleaarch64", "elf32-bigaarch64", "elf32-littleaarch64") +OUTPUT_ARCH(aarch64) +*/ +SECTIONS +{ + PROVIDE(_vdso_data = . - PAGE_SIZE); + . = VDSO_LBASE + SIZEOF_HEADERS; + + .hash : { *(.hash) } :text + .gnu.hash : { *(.gnu.hash) } + .dynsym : { *(.dynsym) } + .dynstr : { *(.dynstr) } + .gnu.version : { *(.gnu.version) } + .gnu.version_d : { *(.gnu.version_d) } + .gnu.version_r : { *(.gnu.version_r) } + + .note : { *(.note.*) } :text :note + + . = ALIGN(16); + + .text : { *(.text*) } :text =0xd503201f + PROVIDE (__etext = .); + PROVIDE (_etext = .); + PROVIDE (etext = .); + + .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr + .eh_frame : { KEEP (*(.eh_frame)) } :text + + .dynamic : { *(.dynamic) } :text :dynamic + + .rodata : { *(.rodata*) } :text + + _end = .; + PROVIDE(end = .); + + /DISCARD/ : { + *(.note.GNU-stack) + *(.data .data.* .gnu.linkonce.d.* .sdata*) + *(.bss .sbss .dynbss .dynsbss) + } +} + +/* + * We must supply the ELF program headers explicitly to get just one + * PT_LOAD segment, and set the flags explicitly to make segments read-only. + */ +PHDRS +{ + text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */ + dynamic PT_DYNAMIC FLAGS(4); /* PF_R */ + note PT_NOTE FLAGS(4); /* PF_R */ + eh_frame_hdr PT_GNU_EH_FRAME; +} + +/* + * This controls what symbols we export from the DSO. + */ +VERSION +{ + LINUX_2.6.39 { + global: + __kernel_rt_sigreturn; + __kernel_gettimeofday; + __kernel_clock_gettime; + __kernel_clock_getres; + local: *; + }; +} + +/* + * Make the sigreturn code visible to the kernel. + */ +VDSO_sigtramp_ilp32 = __kernel_rt_sigreturn; diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index a777ac3..21b3726 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -41,6 +41,12 @@ extern char vdso_start, vdso_end; static unsigned long vdso_pages; static struct page **vdso_pagelist; +#ifdef CONFIG_ARM64_ILP32 +extern char vdso_ilp32_start, vdso_ilp32_end; +static unsigned long vdso_ilp32_pages; +static struct page **vdso_ilp32_pagelist; +#endif + /* * The vDSO data page. */ @@ -110,24 +116,31 @@ int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp) } #endif /* CONFIG_AARCH32_EL0 */ -static struct vm_special_mapping vdso_spec[2]; +static struct vm_special_mapping vdso_spec[2][2]; -static int __init vdso_init(void) +static inline int __init vdso_init_common(char *vdso_start, char *vdso_end, + unsigned long *vdso_pagesp, + struct page ***vdso_pagelistp, + bool ilp32) { int i; + unsigned long vdso_pages; + struct page **vdso_pagelist; - if (memcmp(&vdso_start, "\177ELF", 4)) { + if (memcmp(vdso_start, "\177ELF", 4)) { pr_err("vDSO is not a valid ELF object!\n"); return -EINVAL; } - vdso_pages = (&vdso_end - &vdso_start) >> PAGE_SHIFT; + vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT; + *vdso_pagesp = vdso_pages; pr_info("vdso: %ld pages (%ld code @ %p, %ld data @ %p)\n", - vdso_pages + 1, vdso_pages, &vdso_start, 1L, vdso_data); + vdso_pages + 1, vdso_pages, vdso_start, 1L, vdso_data); /* Allocate the vDSO pagelist, plus a page for the data. */ vdso_pagelist = kcalloc(vdso_pages + 1, sizeof(struct page *), GFP_KERNEL); + *vdso_pagelistp = vdso_pagelist; if (vdso_pagelist == NULL) return -ENOMEM; @@ -136,33 +149,63 @@ static int __init vdso_init(void) /* Grab the vDSO code pages. */ for (i = 0; i < vdso_pages; i++) - vdso_pagelist[i + 1] = virt_to_page(&vdso_start + i * PAGE_SIZE); + vdso_pagelist[i + 1] = virt_to_page(vdso_start + i * PAGE_SIZE); /* Populate the special mapping structures */ - vdso_spec[0] = (struct vm_special_mapping) { + vdso_spec[ilp32][0] = (struct vm_special_mapping) { .name = "[vvar]", .pages = vdso_pagelist, }; - vdso_spec[1] = (struct vm_special_mapping) { + vdso_spec[ilp32][1] = (struct vm_special_mapping) { .name = "[vdso]", .pages = &vdso_pagelist[1], }; return 0; } + +static int __init vdso_init(void) +{ + return vdso_init_common(&vdso_start, &vdso_end, + &vdso_pages, &vdso_pagelist, 0); +} arch_initcall(vdso_init); +#ifdef CONFIG_ARM64_ILP32 +static int __init vdso_ilp32_init(void) +{ + return vdso_init_common(&vdso_ilp32_start, &vdso_ilp32_end, + &vdso_ilp32_pages, &vdso_ilp32_pagelist, 1); +} +arch_initcall(vdso_ilp32_init); +#endif + int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) { struct mm_struct *mm = current->mm; unsigned long vdso_base, vdso_text_len, vdso_mapping_len; void *ret; - - vdso_text_len = vdso_pages << PAGE_SHIFT; + struct page **pagelist; + unsigned long pages; + bool ilp32; + +#ifdef CONFIG_ARM64_ILP32 + ilp32 = is_ilp32_compat_task(); + if (is_ilp32_compat_task()) { + pages = vdso_ilp32_pages; + pagelist = vdso_ilp32_pagelist; + } else +#endif + { + ilp32 = false; + pages = vdso_pages; + pagelist = vdso_pagelist; + } + vdso_text_len = pages << PAGE_SHIFT; /* Be sure to map the data page */ - vdso_mapping_len = vdso_text_len + PAGE_SIZE; + vdso_mapping_len = (pages + 1) << PAGE_SHIFT; down_write(&mm->mmap_sem); vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0); @@ -172,7 +215,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, } ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE, VM_READ|VM_MAYREAD, - &vdso_spec[0]); + &vdso_spec[ilp32][0]); if (IS_ERR(ret)) goto up_fail; @@ -181,7 +224,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, ret = _install_special_mapping(mm, vdso_base, vdso_text_len, VM_READ|VM_EXEC| VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, - &vdso_spec[1]); + &vdso_spec[ilp32][1]); if (IS_ERR(ret)) goto up_fail;
This patch adds the VDSO for ILP32. We need to use a different VDSO than LP64 since ILP32 uses ELF32 while LP64 uses ELF64. After this patch, signal handling works mostly. In that signals go through their action and then returned correctly. Signed-off-by: Andrew Pinski <apinski@cavium.com> --- arch/arm64/include/asm/vdso.h | 4 + arch/arm64/kernel/Makefile | 5 + arch/arm64/kernel/signal.c | 4 + arch/arm64/kernel/vdso-ilp32/.gitignore | 2 + arch/arm64/kernel/vdso-ilp32/Makefile | 72 ++++++++++++++++++ arch/arm64/kernel/vdso-ilp32/vdso-ilp32.S | 33 ++++++++ arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S | 98 +++++++++++++++++++++++++ arch/arm64/kernel/vdso.c | 69 ++++++++++++++--- 8 files changed, 274 insertions(+), 13 deletions(-) create mode 100644 arch/arm64/kernel/vdso-ilp32/.gitignore create mode 100644 arch/arm64/kernel/vdso-ilp32/Makefile create mode 100644 arch/arm64/kernel/vdso-ilp32/vdso-ilp32.S create mode 100644 arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S