From mboxrd@z Thu Jan 1 00:00:00 1970 From: nathan_lynch@mentor.com (Nathan Lynch) Date: Sun, 22 Jun 2014 22:11:55 -0500 Subject: [PATCH v7 6/9] ARM: miscellaneous vdso infrastructure, preparation In-Reply-To: <1403493118-7597-1-git-send-email-nathan_lynch@mentor.com> References: <1403493118-7597-1-git-send-email-nathan_lynch@mentor.com> Message-ID: <1403493118-7597-7-git-send-email-nathan_lynch@mentor.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Define the layout of the data structure shared between kernel and userspace. Track the vdso address in the mm_context; needed for reporting [vdso] via /proc/pid/maps and communicating AT_SYSINFO_EHDR to the ELF loader. Add declarations for vma_is_vdso, arm_install_vdso, and !CONFIG_VDSO implementations of same. The CONFIG_VDSO=y implementations of these come later. Make arch_vma_name recognize a vdso VMA, using vma_is_vdso to return "[vdso]" when appropriate. Define AT_SYSINFO_EHDR, and, if CONFIG_VDSO=y, report the vdso shared object address via the ELF auxiliary vector. Note - this adds the AT_SYSINFO_EHDR in a new user-visible header asm/auxvec.h; this is consistent with other architectures. Signed-off-by: Nathan Lynch --- arch/arm/include/asm/Kbuild | 1 - arch/arm/include/asm/elf.h | 11 +++++++ arch/arm/include/asm/mmu.h | 3 ++ arch/arm/include/asm/vdso.h | 47 ++++++++++++++++++++++++++++ arch/arm/include/asm/vdso_datapage.h | 60 ++++++++++++++++++++++++++++++++++++ arch/arm/include/uapi/asm/Kbuild | 1 + arch/arm/include/uapi/asm/auxvec.h | 7 +++++ arch/arm/kernel/process.c | 14 +++++++-- 8 files changed, 140 insertions(+), 4 deletions(-) create mode 100644 arch/arm/include/asm/vdso.h create mode 100644 arch/arm/include/asm/vdso_datapage.h create mode 100644 arch/arm/include/uapi/asm/auxvec.h diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild index f5a357601983..0e70f40e04ef 100644 --- a/arch/arm/include/asm/Kbuild +++ b/arch/arm/include/asm/Kbuild @@ -1,6 +1,5 @@ -generic-y += auxvec.h generic-y += bitsperlong.h generic-y += cputime.h generic-y += current.h diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h index f4b46d39b9cf..45d2ddff662a 100644 --- a/arch/arm/include/asm/elf.h +++ b/arch/arm/include/asm/elf.h @@ -1,7 +1,9 @@ #ifndef __ASMARM_ELF_H #define __ASMARM_ELF_H +#include #include +#include /* * ELF register definitions.. @@ -129,6 +131,15 @@ extern unsigned long arch_randomize_brk(struct mm_struct *mm); #define arch_randomize_brk arch_randomize_brk #ifdef CONFIG_MMU +#ifdef CONFIG_VDSO +#define ARCH_DLINFO \ +do { \ + /* Account for the data page at the beginning of the [vdso] VMA. */ \ + NEW_AUX_ENT(AT_SYSINFO_EHDR, \ + (elf_addr_t)current->mm->context.vdso + \ + sizeof(union vdso_data_store)); \ +} while (0) +#endif #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1 struct linux_binprm; int arch_setup_additional_pages(struct linux_binprm *, int); diff --git a/arch/arm/include/asm/mmu.h b/arch/arm/include/asm/mmu.h index 64fd15159b7d..a5b47421059d 100644 --- a/arch/arm/include/asm/mmu.h +++ b/arch/arm/include/asm/mmu.h @@ -11,6 +11,9 @@ typedef struct { #endif unsigned int vmalloc_seq; unsigned long sigpage; +#ifdef CONFIG_VDSO + unsigned long vdso; +#endif } mm_context_t; #ifdef CONFIG_CPU_HAS_ASID diff --git a/arch/arm/include/asm/vdso.h b/arch/arm/include/asm/vdso.h new file mode 100644 index 000000000000..0e2a6154eceb --- /dev/null +++ b/arch/arm/include/asm/vdso.h @@ -0,0 +1,47 @@ +#ifndef __ASM_VDSO_H +#define __ASM_VDSO_H + +#ifdef __KERNEL__ + +#ifndef __ASSEMBLY__ + +#include +#include + +#ifdef CONFIG_VDSO + +static inline bool vma_is_vdso(struct vm_area_struct *vma) +{ + if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso) + return true; + return false; +} + +void arm_install_vdso(struct mm_struct *mm, unsigned long addr); + +extern char vdso_start, vdso_end; + +extern unsigned long vdso_mapping_len; + +#else /* CONFIG_VDSO */ + +static inline bool vma_is_vdso(struct vm_area_struct *vma) +{ + return false; +} + +static inline void arm_install_vdso(struct mm_struct *mm, unsigned long addr) +{ +} + +#define vdso_mapping_len 0 + +#endif /* CONFIG_VDSO */ + +#endif /* __ASSEMBLY__ */ + +#define VDSO_LBASE 0x0 + +#endif /* __KERNEL__ */ + +#endif /* __ASM_VDSO_H */ diff --git a/arch/arm/include/asm/vdso_datapage.h b/arch/arm/include/asm/vdso_datapage.h new file mode 100644 index 000000000000..f08bdb73d3f4 --- /dev/null +++ b/arch/arm/include/asm/vdso_datapage.h @@ -0,0 +1,60 @@ +/* + * Adapted from arm64 version. + * + * 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 . + */ +#ifndef __ASM_VDSO_DATAPAGE_H +#define __ASM_VDSO_DATAPAGE_H + +#ifdef __KERNEL__ + +#ifndef __ASSEMBLY__ + +#include + +/* Try to be cache-friendly on systems that don't implement the + * generic timer: fit the unconditionally updated fields in the first + * 32 bytes. + */ +struct vdso_data { + u32 seq_count; /* sequence count - odd during updates */ + u16 use_syscall; /* whether to fall back to syscalls */ + u16 cs_shift; /* clocksource shift */ + u32 xtime_coarse_sec; /* coarse time */ + u32 xtime_coarse_nsec; + + u32 wtm_clock_sec; /* wall to monotonic offset */ + u32 wtm_clock_nsec; + u32 xtime_clock_sec; /* CLOCK_REALTIME - seconds */ + u32 cs_mult; /* clocksource multiplier */ + + u64 cs_cycle_last; /* last cycle value */ + u64 cs_mask; /* clocksource mask */ + + u64 xtime_clock_snsec; /* CLOCK_REALTIME sub-ns base */ + u32 tz_minuteswest; /* timezone info for gettimeofday(2) */ + u32 tz_dsttime; +}; + +union vdso_data_store { + struct vdso_data data; + u8 page[PAGE_SIZE]; +}; + +#endif /* !__ASSEMBLY__ */ + +#endif /* __KERNEL__ */ + +#endif /* __ASM_VDSO_DATAPAGE_H */ diff --git a/arch/arm/include/uapi/asm/Kbuild b/arch/arm/include/uapi/asm/Kbuild index 70a1c9da30ca..a1c05f93d920 100644 --- a/arch/arm/include/uapi/asm/Kbuild +++ b/arch/arm/include/uapi/asm/Kbuild @@ -1,6 +1,7 @@ # UAPI Header export list include include/uapi/asm-generic/Kbuild.asm +header-y += auxvec.h header-y += byteorder.h header-y += fcntl.h header-y += hwcap.h diff --git a/arch/arm/include/uapi/asm/auxvec.h b/arch/arm/include/uapi/asm/auxvec.h new file mode 100644 index 000000000000..f56936b97ec2 --- /dev/null +++ b/arch/arm/include/uapi/asm/auxvec.h @@ -0,0 +1,7 @@ +#ifndef __ASM_AUXVEC_H +#define __ASM_AUXVEC_H + +/* vDSO location */ +#define AT_SYSINFO_EHDR 33 + +#endif diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 219a0d1d10fc..40445fb71ac9 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -41,6 +41,7 @@ #include #include #include +#include #ifdef CONFIG_CC_STACKPROTECTOR #include @@ -472,9 +473,16 @@ int in_gate_area_no_mm(unsigned long addr) const char *arch_vma_name(struct vm_area_struct *vma) { - return is_gate_vma(vma) ? "[vectors]" : - (vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ? - "[sigpage]" : NULL; + if (is_gate_vma(vma)) + return "[vectors]"; + + if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) + return "[sigpage]"; + + if (vma_is_vdso(vma)) + return "[vdso]"; + + return NULL; } static unsigned long vdso_addr(const struct mm_struct *mm, unsigned int npages) -- 1.9.3