[PATCH v11 1/4] ARM: miscellaneous vdso infrastructure, preparation
Nathan Lynch
nathan_lynch at mentor.com
Fri Mar 20 14:13:20 PDT 2015
Define the layout of the data structure shared between kernel and
userspace.
Track the vdso address in the mm_context; needed for communicating
AT_SYSINFO_EHDR to the ELF loader.
Add declarations for arm_install_vdso; implementation is in a
following patch.
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 <nathan_lynch at mentor.com>
---
arch/arm/include/asm/Kbuild | 1 -
arch/arm/include/asm/auxvec.h | 1 +
arch/arm/include/asm/elf.h | 9 ++++++
arch/arm/include/asm/mmu.h | 3 ++
arch/arm/include/asm/vdso.h | 32 +++++++++++++++++++
arch/arm/include/asm/vdso_datapage.h | 60 ++++++++++++++++++++++++++++++++++++
arch/arm/include/uapi/asm/Kbuild | 1 +
arch/arm/include/uapi/asm/auxvec.h | 7 +++++
8 files changed, 113 insertions(+), 1 deletion(-)
create mode 100644 arch/arm/include/asm/auxvec.h
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 fe74c0d1e485..eb0f43f3e3f1 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/auxvec.h b/arch/arm/include/asm/auxvec.h
new file mode 100644
index 000000000000..fbd388c46299
--- /dev/null
+++ b/arch/arm/include/asm/auxvec.h
@@ -0,0 +1 @@
+#include <uapi/asm/auxvec.h>
diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h
index afb9cafd3786..ac3f17fb4c8d 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 <asm/auxvec.h>
#include <asm/hwcap.h>
+#include <asm/vdso_datapage.h>
/*
* ELF register definitions..
@@ -130,6 +132,13 @@ 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 { \
+ NEW_AUX_ENT(AT_SYSINFO_EHDR, \
+ (elf_addr_t)current->mm->context.vdso); \
+} 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..d0295f1dd1a3
--- /dev/null
+++ b/arch/arm/include/asm/vdso.h
@@ -0,0 +1,32 @@
+#ifndef __ASM_VDSO_H
+#define __ASM_VDSO_H
+
+#ifdef __KERNEL__
+
+#ifndef __ASSEMBLY__
+
+struct mm_struct;
+
+#ifdef CONFIG_VDSO
+
+void arm_install_vdso(struct mm_struct *mm, unsigned long addr);
+
+extern char vdso_start, vdso_end;
+
+extern unsigned int vdso_total_pages;
+
+#else /* CONFIG_VDSO */
+
+static inline void arm_install_vdso(struct mm_struct *mm, unsigned long addr)
+{
+}
+
+#define vdso_total_pages 0
+
+#endif /* CONFIG_VDSO */
+
+#endif /* __ASSEMBLY__ */
+
+#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..9be259442fca
--- /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 <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_VDSO_DATAPAGE_H
+#define __ASM_VDSO_DATAPAGE_H
+
+#ifdef __KERNEL__
+
+#ifndef __ASSEMBLY__
+
+#include <asm/page.h>
+
+/* 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 tk_is_cntvct; /* fall back to syscall if false */
+ 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..cb02a767a500
--- /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
--
1.9.3
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