From: Alex Smith <alex.smith@xxxxxxxxxx>
Add an initial implementation of a proper (i.e. an ELF shared library)
VDSO. With this commit it does not export any symbols, it only replaces
the current signal return trampoline page. A later commit will add user
implementations of gettimeofday()/clock_gettime().
To support both new toolchains and old ones which don't generate ABI
flags section, we define its content manually and then use a tool
(genvdso) to patch up the section to have the correct name and type.
genvdso also extracts symbol offsets ({,rt_}sigreturn) needed by the
kernel, and generates a C file containing a "struct mips_vdso_image"
containing both the VDSO data and these offsets. This C file is
compiled into the kernel.
On 64-bit kernels we require a different VDSO for each supported ABI,
so we may build up to 3 different VDSOs. The VDSO to use is selected by
the mips_abi structure.
A kernel/user shared data page is created and mapped below the VDSO
image. This is currently empty, but will be used by the user time
function implementations which are added later.
[markos.chandras@xxxxxxxxxx:
- Add more comments
- Move abi detection in genvdso.h since it's the get_symbol function
that needs it.
- Add an R6 specific way to calculate the base address of VDSO in order
to avoid the branch instruction which affects performance.
- Do not patch .gnu.attributes since it's not needed for dynamic linking.
- Simplify Makefile a little bit.
- checkpatch fixes
- Restrict VDSO support for binutils < 2.25 for pre-R6
- Include atomic64.h for O32 variant on MIPS64]
Cc: Matthew Fortune <matthew.fortune@xxxxxxxxxx>
Signed-off-by: Alex Smith <alex.smith@xxxxxxxxxx>
Signed-off-by: Markos Chandras <markos.chandras@xxxxxxxxxx>
---
Changes since v2:
- Restrict VDSO support for pre-R6 and binutils < 2.25 because a
suitable relocation is missing and we can't determine the base
of the VDSO during runtime. VDSO will work fine for R6
(because an R6 instruction is used to determine the base address)
or binutils >= 2.25
Changes since v1:
- Reword and rearrange comments
http://www.linux-mips.org/archives/linux-mips/2015-09/msg00315.html
---
arch/mips/Kbuild | 1 +
arch/mips/include/asm/abi.h | 5 +-
arch/mips/include/asm/elf.h | 7 +
arch/mips/include/asm/processor.h | 8 +-
arch/mips/include/asm/vdso.h | 73 +++++++--
arch/mips/include/uapi/asm/Kbuild | 2 +-
arch/mips/include/uapi/asm/auxvec.h | 17 +++
arch/mips/kernel/signal.c | 12 +-
arch/mips/kernel/signal32.c | 7 +-
arch/mips/kernel/signal_n32.c | 5 +-
arch/mips/kernel/vdso.c | 160 ++++++++++----------
arch/mips/vdso/.gitignore | 4 +
arch/mips/vdso/Makefile | 160 ++++++++++++++++++++
arch/mips/vdso/elf.S | 68 +++++++++
arch/mips/vdso/genvdso.c | 293 ++++++++++++++++++++++++++++++++++++
arch/mips/vdso/genvdso.h | 187 +++++++++++++++++++++++
arch/mips/vdso/sigreturn.S | 49 ++++++
arch/mips/vdso/vdso.h | 80 ++++++++++
arch/mips/vdso/vdso.lds.S | 100 ++++++++++++
19 files changed, 1114 insertions(+), 124 deletions(-)
create mode 100644 arch/mips/include/uapi/asm/auxvec.h
create mode 100644 arch/mips/vdso/.gitignore
create mode 100644 arch/mips/vdso/Makefile
create mode 100644 arch/mips/vdso/elf.S
create mode 100644 arch/mips/vdso/genvdso.c
create mode 100644 arch/mips/vdso/genvdso.h
create mode 100644 arch/mips/vdso/sigreturn.S
create mode 100644 arch/mips/vdso/vdso.h
create mode 100644 arch/mips/vdso/vdso.lds.S
diff --git a/arch/mips/Kbuild b/arch/mips/Kbuild
index dd295335891a..5c3f688a5232 100644
--- a/arch/mips/Kbuild
+++ b/arch/mips/Kbuild
@@ -17,6 +17,7 @@ obj- := $(platform-)
obj-y += kernel/
obj-y += mm/
obj-y += net/
+obj-y += vdso/
ifdef CONFIG_KVM
obj-y += kvm/
diff --git a/arch/mips/include/asm/abi.h b/arch/mips/include/asm/abi.h
index 37f84078e78a..940760844e2f 100644
--- a/arch/mips/include/asm/abi.h
+++ b/arch/mips/include/asm/abi.h
@@ -11,19 +11,20 @@
#include <asm/signal.h>
#include <asm/siginfo.h>
+#include <asm/vdso.h>
struct mips_abi {
int (* const setup_frame)(void *sig_return, struct ksignal *ksig,
struct pt_regs *regs, sigset_t *set);
- const unsigned long signal_return_offset;
int (* const setup_rt_frame)(void *sig_return, struct ksignal *ksig,
struct pt_regs *regs, sigset_t *set);
- const unsigned long rt_signal_return_offset;
const unsigned long restart;
unsigned off_sc_fpregs;
unsigned off_sc_fpc_csr;
unsigned off_sc_used_math;
+
+ struct mips_vdso_image *vdso;
};
#endif /* _ASM_ABI_H */
diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h
index 53b26933b12c..b01a6ff468e0 100644
--- a/arch/mips/include/asm/elf.h
+++ b/arch/mips/include/asm/elf.h
@@ -8,6 +8,7 @@
#ifndef _ASM_ELF_H
#define _ASM_ELF_H
+#include <linux/auxvec.h>
#include <linux/fs.h>
#include <uapi/linux/elf.h>
@@ -419,6 +420,12 @@ extern const char *__elf_platform;
#define ELF_ET_DYN_BASE (TASK_SIZE / 3 * 2)
#endif
+#define ARCH_DLINFO \
+do { \
+ NEW_AUX_ENT(AT_SYSINFO_EHDR, \
+ (unsigned long)current->mm->context.vdso); \
+} while (0)
+
#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
struct linux_binprm;
extern int arch_setup_additional_pages(struct linux_binprm *bprm,
diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h
index 59ee6dcf6eed..3f832c3dd8f5 100644
--- a/arch/mips/include/asm/processor.h
+++ b/arch/mips/include/asm/processor.h
@@ -36,12 +36,6 @@ extern unsigned int vced_count, vcei_count;
*/
#define HAVE_ARCH_PICK_MMAP_LAYOUT 1
-/*
- * A special page (the vdso) is mapped into all processes at the very
- * top of the virtual memory space.
- */
-#define SPECIAL_PAGES_SIZE PAGE_SIZE
-
#ifdef CONFIG_32BIT
#ifdef CONFIG_KVM_GUEST
/* User space process size is limited to 1GB in KVM Guest Mode */
@@ -80,7 +74,7 @@ extern unsigned int vced_count, vcei_count;
#endif
-#define STACK_TOP ((TASK_SIZE & PAGE_MASK) - SPECIAL_PAGES_SIZE)
+#define STACK_TOP (TASK_SIZE & PAGE_MASK)
/*
* This decides where the kernel will search for a free chunk of vm
diff --git a/arch/mips/include/asm/vdso.h b/arch/mips/include/asm/vdso.h
index cca56aa40ff4..db2d45be8f2e 100644
--- a/arch/mips/include/asm/vdso.h
+++ b/arch/mips/include/asm/vdso.h
@@ -1,29 +1,70 @@
/*
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file "COPYING" in the main directory of this archive
- * for more details.
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@xxxxxxxxxx>
*
- * Copyright (C) 2009 Cavium Networks
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
*/
#ifndef __ASM_VDSO_H
#define __ASM_VDSO_H
-#include <linux/types.h>
+#include <linux/mm_types.h>
+/**
+ * struct mips_vdso_image - Details of a VDSO image.
+ * @data: Pointer to VDSO image data (page-aligned).
+ * @size: Size of the VDSO image data (page-aligned).
+ * @off_sigreturn: Offset of the sigreturn() trampoline.
+ * @off_rt_sigreturn: Offset of the rt_sigreturn() trampoline.
+ * @mapping: Special mapping structure.
+ *
+ * This structure contains details of a VDSO image, including the image data
+ * and offsets of certain symbols required by the kernel. It is generated as
+ * part of the VDSO build process, aside from the mapping page array, which is
+ * populated at runtime.
+ */
+struct mips_vdso_image {
+ void *data;
+ unsigned long size;
-#ifdef CONFIG_32BIT
-struct mips_vdso {
- u32 signal_trampoline[2];
- u32 rt_signal_trampoline[2];
+ unsigned long off_sigreturn;
+ unsigned long off_rt_sigreturn;
+
+ struct vm_special_mapping mapping;
};
-#else /* !CONFIG_32BIT */
-struct mips_vdso {
- u32 o32_signal_trampoline[2];
- u32 o32_rt_signal_trampoline[2];
- u32 rt_signal_trampoline[2];
- u32 n32_rt_signal_trampoline[2];
+
+/*
+ * The following structures are auto-generated as part of the build for each
+ * ABI by genvdso, see arch/mips/vdso/Makefile.
+ */
+
+extern struct mips_vdso_image vdso_image;
+
+#ifdef CONFIG_MIPS32_O32
+extern struct mips_vdso_image vdso_image_o32;
+#endif
+
+#ifdef CONFIG_MIPS32_N32
+extern struct mips_vdso_image vdso_image_n32;
+#endif
+
+/**
+ * union mips_vdso_data - Data provided by the kernel for the VDSO.
+ *
+ * This structure contains data needed by functions within the VDSO. It is
+ * populated by the kernel and mapped read-only into user memory.
+ *
+ * Note: Care should be taken when modifying as the layout must remain the same
+ * for both 64- and 32-bit (for 32-bit userland on 64-bit kernel).
+ */
+union mips_vdso_data {
+ struct {
+ };
+
+ u8 page[PAGE_SIZE];
};
-#endif /* CONFIG_32BIT */
#endif /* __ASM_VDSO_H */
diff --git a/arch/mips/include/uapi/asm/Kbuild b/arch/mips/include/uapi/asm/Kbuild
index 96fe7395ed8d..f2cf41461146 100644
--- a/arch/mips/include/uapi/asm/Kbuild
+++ b/arch/mips/include/uapi/asm/Kbuild
@@ -1,9 +1,9 @@
# UAPI Header export list
include include/uapi/asm-generic/Kbuild.asm
-generic-y += auxvec.h
generic-y += ipcbuf.h
+header-y += auxvec.h
header-y += bitfield.h
header-y += bitsperlong.h
header-y += break.h
diff --git a/arch/mips/include/uapi/asm/auxvec.h b/arch/mips/include/uapi/asm/auxvec.h
new file mode 100644
index 000000000000..c9c7195272c4
--- /dev/null
+++ b/arch/mips/include/uapi/asm/auxvec.h
@@ -0,0 +1,17 @@
+/*
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#ifndef __ASM_AUXVEC_H
+#define __ASM_AUXVEC_H
+
+/* Location of VDSO image. */
+#define AT_SYSINFO_EHDR 33
+
+#endif /* __ASM_AUXVEC_H */
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 2fec67bfc457..bf792e2839a6 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -36,7 +36,6 @@
#include <asm/ucontext.h>
#include <asm/cpu-features.h>
#include <asm/war.h>
-#include <asm/vdso.h>
#include <asm/dsp.h>
#include <asm/inst.h>
#include <asm/msa.h>
@@ -752,16 +751,15 @@ static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
struct mips_abi mips_abi = {
#ifdef CONFIG_TRAD_SIGNALS
.setup_frame = setup_frame,
- .signal_return_offset = offsetof(struct mips_vdso, signal_trampoline),
#endif
.setup_rt_frame = setup_rt_frame,
- .rt_signal_return_offset =
- offsetof(struct mips_vdso, rt_signal_trampoline),
.restart = __NR_restart_syscall,
.off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
.off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
.off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
+
+ .vdso = &vdso_image,
};
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
@@ -801,11 +799,11 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
}
if (sig_uses_siginfo(&ksig->ka))
- ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset,
+ ret = abi->setup_rt_frame(vdso + abi->vdso->off_rt_sigreturn,
ksig, regs, oldset);
else
- ret = abi->setup_frame(vdso + abi->signal_return_offset, ksig,
- regs, oldset);
+ ret = abi->setup_frame(vdso + abi->vdso->off_sigreturn,
+ ksig, regs, oldset);
signal_setup_done(ret, ksig, 0);
}
diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c
index f7e89524e316..4909639aa35b 100644
--- a/arch/mips/kernel/signal32.c
+++ b/arch/mips/kernel/signal32.c
@@ -31,7 +31,6 @@
#include <asm/ucontext.h>
#include <asm/fpu.h>
#include <asm/war.h>
-#include <asm/vdso.h>
#include <asm/dsp.h>
#include "signal-common.h"
@@ -406,14 +405,12 @@ static int setup_rt_frame_32(void *sig_return, struct ksignal *ksig,
*/
struct mips_abi mips_abi_32 = {
.setup_frame = setup_frame_32,
- .signal_return_offset =
- offsetof(struct mips_vdso, o32_signal_trampoline),
.setup_rt_frame = setup_rt_frame_32,
- .rt_signal_return_offset =
- offsetof(struct mips_vdso, o32_rt_signal_trampoline),
.restart = __NR_O32_restart_syscall,
.off_sc_fpregs = offsetof(struct sigcontext32, sc_fpregs),
.off_sc_fpc_csr = offsetof(struct sigcontext32, sc_fpc_csr),
.off_sc_used_math = offsetof(struct sigcontext32, sc_used_math),
+
+ .vdso = &vdso_image_o32,
};
diff --git a/arch/mips/kernel/signal_n32.c b/arch/mips/kernel/signal_n32.c
index 0d017fdcaf07..a7bc38430500 100644
--- a/arch/mips/kernel/signal_n32.c
+++ b/arch/mips/kernel/signal_n32.c
@@ -38,7 +38,6 @@
#include <asm/fpu.h>
#include <asm/cpu-features.h>
#include <asm/war.h>
-#include <asm/vdso.h>
#include "signal-common.h"
@@ -151,11 +150,11 @@ static int setup_rt_frame_n32(void *sig_return, struct ksignal *ksig,
struct mips_abi mips_abi_n32 = {
.setup_rt_frame = setup_rt_frame_n32,
- .rt_signal_return_offset =
- offsetof(struct mips_vdso, n32_rt_signal_trampoline),
.restart = __NR_N32_restart_syscall,
.off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
.off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
.off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
+
+ .vdso = &vdso_image_n32,
};
diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c
index ed2a278722a9..56cc3c4377fb 100644
--- a/arch/mips/kernel/vdso.c
+++ b/arch/mips/kernel/vdso.c
@@ -1,122 +1,116 @@
/*
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file "COPYING" in the main directory of this archive
- * for more details.
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@xxxxxxxxxx>
*
- * Copyright (C) 2009, 2010 Cavium Networks, Inc.
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
*/
-
-#include <linux/kernel.h>
-#include <linux/err.h>
-#include <linux/sched.h>
-#include <linux/mm.h>
-#include <linux/init.h>
#include <linux/binfmts.h>
#include <linux/elf.h>
-#include <linux/vmalloc.h>
-#include <linux/unistd.h>
-#include <linux/random.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <asm/abi.h>
#include <asm/vdso.h>
-#include <asm/uasm.h>
-#include <asm/processor.h>
+
+/* Kernel-provided data used by the VDSO. */
+static union mips_vdso_data vdso_data __page_aligned_data;
/*
- * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
+ * Mapping for the VDSO data pages. The real pages are mapped manually, as
+ * what we map and where within the area they are mapped is determined at
+ * runtime.
*/
-#define __NR_O32_sigreturn 4119
-#define __NR_O32_rt_sigreturn 4193
-#define __NR_N32_rt_sigreturn 6211
+static struct page *no_pages[] = { NULL };
+static struct vm_special_mapping vdso_vvar_mapping = {
+ .name = "[vvar]",
+ .pages = no_pages,
+};
-static struct page *vdso_page;
-
-static void __init install_trampoline(u32 *tramp, unsigned int sigreturn)
+static void __init init_vdso_image(struct mips_vdso_image *image)
{
- uasm_i_addiu(&tramp, 2, 0, sigreturn); /* li v0, sigreturn */
- uasm_i_syscall(&tramp, 0);
+ unsigned long num_pages, i;
+
+ BUG_ON(!PAGE_ALIGNED(image->data));
+ BUG_ON(!PAGE_ALIGNED(image->size));
+
+ num_pages = image->size / PAGE_SIZE;
+
+ for (i = 0; i < num_pages; i++) {
+ image->mapping.pages[i] =
+ virt_to_page(image->data + (i * PAGE_SIZE));
+ }
}
static int __init init_vdso(void)
{
- struct mips_vdso *vdso;
-
- vdso_page = alloc_page(GFP_KERNEL);
- if (!vdso_page)
- panic("Cannot allocate vdso");
-
- vdso = vmap(&vdso_page, 1, 0, PAGE_KERNEL);
- if (!vdso)
- panic("Cannot map vdso");
- clear_page(vdso);
-
- install_trampoline(vdso->rt_signal_trampoline, __NR_rt_sigreturn);
-#ifdef CONFIG_32BIT
- install_trampoline(vdso->signal_trampoline, __NR_sigreturn);
-#else
- install_trampoline(vdso->n32_rt_signal_trampoline,
- __NR_N32_rt_sigreturn);
- install_trampoline(vdso->o32_signal_trampoline, __NR_O32_sigreturn);
- install_trampoline(vdso->o32_rt_signal_trampoline,
- __NR_O32_rt_sigreturn);
+ init_vdso_image(&vdso_image);
+
+#ifdef CONFIG_MIPS32_O32
+ init_vdso_image(&vdso_image_o32);
#endif
- vunmap(vdso);
+#ifdef CONFIG_MIPS32_N32
+ init_vdso_image(&vdso_image_n32);
+#endif
return 0;
}
subsys_initcall(init_vdso);
-static unsigned long vdso_addr(unsigned long start)
-{
- unsigned long offset = 0UL;
-
- if (current->flags & PF_RANDOMIZE) {
- offset = get_random_int();
- offset <<= PAGE_SHIFT;
- if (TASK_IS_32BIT_ADDR)
- offset &= 0xfffffful;
- else
- offset &= 0xffffffful;
- }
-
- return STACK_TOP + offset;
-}
-
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
- int ret;
- unsigned long addr;
+ struct mips_vdso_image *image = current->thread.abi->vdso;
struct mm_struct *mm = current->mm;
+ unsigned long base, vdso_addr;
+ struct vm_area_struct *vma;
+ int ret;
down_write(&mm->mmap_sem);
- addr = vdso_addr(mm->start_stack);
-
- addr = get_unmapped_area(NULL, addr, PAGE_SIZE, 0, 0);
- if (IS_ERR_VALUE(addr)) {
- ret = addr;
- goto up_fail;
+ base = get_unmapped_area(NULL, 0, PAGE_SIZE + image->size, 0, 0);
+ if (IS_ERR_VALUE(base)) {
+ ret = base;
+ goto out;
}
- ret = install_special_mapping(mm, addr, PAGE_SIZE,
- VM_READ|VM_EXEC|
- VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
- &vdso_page);
+ vdso_addr = base + PAGE_SIZE;
+
+ vma = _install_special_mapping(mm, base, PAGE_SIZE,
+ VM_READ | VM_MAYREAD,
+ &vdso_vvar_mapping);
+ if (IS_ERR(vma)) {
+ ret = PTR_ERR(vma);
+ goto out;
+ }
+ /* Map data page. */
+ ret = remap_pfn_range(vma, base,
+ virt_to_phys(&vdso_data) >> PAGE_SHIFT,
+ PAGE_SIZE, PAGE_READONLY);
if (ret)
- goto up_fail;
+ goto out;
+
+ /* Map VDSO image. */
+ vma = _install_special_mapping(mm, vdso_addr, image->size,
+ VM_READ | VM_EXEC |
+ VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
+ &image->mapping);
+ if (IS_ERR(vma)) {
+ ret = PTR_ERR(vma);
+ goto out;
+ }
- mm->context.vdso = (void *)addr;
+ mm->context.vdso = (void *)vdso_addr;
+ ret = 0;
-up_fail:
+out:
up_write(&mm->mmap_sem);
return ret;
}
-
-const char *arch_vma_name(struct vm_area_struct *vma)
-{
- if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
- return "[vdso]";
- return NULL;
-}
diff --git a/arch/mips/vdso/.gitignore b/arch/mips/vdso/.gitignore
new file mode 100644
index 000000000000..5286a7d73d79
--- /dev/null
+++ b/arch/mips/vdso/.gitignore
@@ -0,0 +1,4 @@
+*.so*
+vdso-*image.c
+genvdso
+vdso*.lds
diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile
new file mode 100644
index 000000000000..ef5f348f386a
--- /dev/null
+++ b/arch/mips/vdso/Makefile
@@ -0,0 +1,160 @@
+# Objects to go into the VDSO.
+obj-vdso-y := elf.o gettimeofday.o sigreturn.o
+
+# Common compiler flags between ABIs.
+ccflags-vdso := \
+ $(filter -I%,$(KBUILD_CFLAGS)) \
+ $(filter -E%,$(KBUILD_CFLAGS)) \
+ $(filter -march=%,$(KBUILD_CFLAGS))
+cflags-vdso := $(ccflags-vdso) \
+ $(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \
+ -O2 -g -fPIC -fno-common -fno-builtin -G 0 -DDISABLE_BRANCH_PROFILING \
+ $(call cc-option, -fno-stack-protector)
+aflags-vdso := $(ccflags-vdso) \
+ $(filter -I%,$(KBUILD_CFLAGS)) \
+ $(filter -E%,$(KBUILD_CFLAGS)) \
+ -D__ASSEMBLY__ -Wa,-gdwarf-2
+
+#
+# For the pre-R6 code in arch/mips/vdso/vdso.h for locating
+# the base address of VDSO, the linker will emit a R_MIPS_PC32
+# relocation in binutils > 2.25 but it will fail with older versions
+# because that relocation is not supported for that symbol. As a result
+# of which we are forced to disable the VDSO symbols when building
+# with < 2.25 binutils on pre-R6 kernels. For more references on why we
+# can't use other methods to get the base address of VDSO please refer to
+# the comments on that file.
+#
+ifndef CONFIG_CPU_MIPSR6
+ ifeq ($(call ld-ifversion, -gt, 22400000, y),)
+ $(warning MIPS VDSO requires binutils > 2.24)
+ obj-vdso-y := $(filter-out gettimeofday.o, $(obj-vdso-y))
+ ccflags-vdso += -DDISABLE_MIPS_VDSO
+ endif
+endif
+
+# VDSO linker flags.
+VDSO_LDFLAGS := \
+ -Wl,-Bsymbolic -Wl,--no-undefined -Wl,-soname=linux-vdso.so.1 \
+ -nostdlib -shared \
+ $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
+ $(call cc-ldoption, -Wl$(comma)--build-id)
+
+GCOV_PROFILE := n
+
+#
+# Shared build commands.
+#
+
+quiet_cmd_vdsold = VDSO $@
+ cmd_vdsold = $(CC) $(c_flags) $(VDSO_LDFLAGS) \
+ -Wl,-T $(filter %.lds,$^) $(filter %.o,$^) -o $@
+
+hostprogs-y := genvdso
+
+quiet_cmd_genvdso = GENVDSO $@
+define cmd_genvdso
+ cp $< $(<:%.dbg=%) && \
+ $(OBJCOPY) -S $< $(<:%.dbg=%) && \
+ $(obj)/genvdso $< $(<:%.dbg=%) $@ $(VDSO_NAME)
+endef
+
+#
+# Build native VDSO.
+#
+
+native-abi := $(filter -mabi=%,$(KBUILD_CFLAGS))
+
+targets += $(obj-vdso-y)
+targets += vdso.lds vdso.so.dbg vdso.so vdso-image.c
+
+obj-vdso := $(obj-vdso-y:%.o=$(obj)/%.o)
+
+$(obj-vdso): KBUILD_CFLAGS := $(cflags-vdso) $(native-abi)
+$(obj-vdso): KBUILD_AFLAGS := $(aflags-vdso) $(native-abi)
+
+$(obj)/vdso.lds: KBUILD_CPPFLAGS := $(native-abi)
+
+$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
+ $(call if_changed,vdsold)
+
+$(obj)/vdso-image.c: $(obj)/vdso.so.dbg $(obj)/genvdso FORCE
+ $(call if_changed,genvdso)
+
+obj-y += vdso-image.o
+
+#
+# Build O32 VDSO.
+#
+
+# Define these outside the ifdef to ensure they are picked up by clean.
+targets += $(obj-vdso-y:%.o=%-o32.o)
+targets += vdso-o32.lds vdso-o32.so.dbg vdso-o32.so vdso-o32-image.c
+
+ifdef CONFIG_MIPS32_O32
+
+obj-vdso-o32 := $(obj-vdso-y:%.o=$(obj)/%-o32.o)
+
+$(obj-vdso-o32): KBUILD_CFLAGS := $(cflags-vdso) -mabi=32
+$(obj-vdso-o32): KBUILD_AFLAGS := $(aflags-vdso) -mabi=32
+
+$(obj)/%-o32.o: $(src)/%.S FORCE
+ $(call if_changed_dep,as_o_S)
+
+$(obj)/%-o32.o: $(src)/%.c FORCE
+ $(call cmd,force_checksrc)
+ $(call if_changed_rule,cc_o_c)
+
+$(obj)/vdso-o32.lds: KBUILD_CPPFLAGS := -mabi=32
+$(obj)/vdso-o32.lds: $(src)/vdso.lds.S FORCE
+ $(call if_changed_dep,cpp_lds_S)
+
+$(obj)/vdso-o32.so.dbg: $(obj)/vdso-o32.lds $(obj-vdso-o32) FORCE
+ $(call if_changed,vdsold)
+
+$(obj)/vdso-o32-image.c: VDSO_NAME := o32
+$(obj)/vdso-o32-image.c: $(obj)/vdso-o32.so.dbg $(obj)/genvdso FORCE
+ $(call if_changed,genvdso)
+
+obj-y += vdso-o32-image.o
+
+endif
+
+#
+# Build N32 VDSO.
+#
+
+targets += $(obj-vdso-y:%.o=%-n32.o)
+targets += vdso-n32.lds vdso-n32.so.dbg vdso-n32.so vdso-n32-image.c
+
+ifdef CONFIG_MIPS32_N32
+
+obj-vdso-n32 := $(obj-vdso-y:%.o=$(obj)/%-n32.o)
+
+$(obj-vdso-n32): KBUILD_CFLAGS := $(cflags-vdso) -mabi=n32
+$(obj-vdso-n32): KBUILD_AFLAGS := $(aflags-vdso) -mabi=n32
+
+$(obj)/%-n32.o: $(src)/%.S FORCE
+ $(call if_changed_dep,as_o_S)
+
+$(obj)/%-n32.o: $(src)/%.c FORCE
+ $(call cmd,force_checksrc)
+ $(call if_changed_rule,cc_o_c)
+
+$(obj)/vdso-n32.lds: KBUILD_CPPFLAGS := -mabi=n32
+$(obj)/vdso-n32.lds: $(src)/vdso.lds.S FORCE
+ $(call if_changed_dep,cpp_lds_S)
+
+$(obj)/vdso-n32.so.dbg: $(obj)/vdso-n32.lds $(obj-vdso-n32) FORCE
+ $(call if_changed,vdsold)
+
+$(obj)/vdso-n32-image.c: VDSO_NAME := n32
+$(obj)/vdso-n32-image.c: $(obj)/vdso-n32.so.dbg $(obj)/genvdso FORCE
+ $(call if_changed,genvdso)
+
+obj-y += vdso-n32-image.o
+
+endif
+
+# FIXME: Need install rule for debug.
+# Needs to deal with dependency for generation of dbg by cmd_genvdso...
diff --git a/arch/mips/vdso/elf.S b/arch/mips/vdso/elf.S
new file mode 100644
index 000000000000..be37bbb1f061
--- /dev/null
+++ b/arch/mips/vdso/elf.S
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include "vdso.h"
+
+#include <linux/elfnote.h>
+#include <linux/version.h>
+
+ELFNOTE_START(Linux, 0, "a")
+ .long LINUX_VERSION_CODE
+ELFNOTE_END
+
+/*
+ * The .MIPS.abiflags section must be defined with the FP ABI flags set
+ * to 'any' to be able to link with both old and new libraries.
+ * Newer toolchains are capable of automatically generating this, but we want
+ * to work with older toolchains as well. Therefore, we define the contents of
+ * this section here (under different names), and then genvdso will patch
+ * it to have the correct name and type.
+ *
+ * We base the .MIPS.abiflags section on preprocessor definitions rather than
+ * CONFIG_* because we need to match the particular ABI we are building the
+ * VDSO for.
+ *
+ * See https://dmz-portal.mips.com/wiki/MIPS_O32_ABI_-_FR0_and_FR1_Interlinking
+ * for the .MIPS.abiflags section description.
+ */
+
+ .section .mips_abiflags, "a"
+ .align 3
+__mips_abiflags:
+ .hword 0 /* version */
+ .byte __mips /* isa_level */
+
+ /* isa_rev */
+#ifdef __mips_isa_rev
+ .byte __mips_isa_rev
+#else
+ .byte 0
+#endif
+
+ /* gpr_size */
+#ifdef __mips64
+ .byte 2 /* AFL_REG_64 */
+#else
+ .byte 1 /* AFL_REG_32 */
+#endif
+
+ /* cpr1_size */
+#if (defined(__mips_isa_rev) && __mips_isa_rev >= 6) || defined(__mips64)
+ .byte 2 /* AFL_REG_64 */
+#else
+ .byte 1 /* AFL_REG_32 */
+#endif
+
+ .byte 0 /* cpr2_size (AFL_REG_NONE) */
+ .byte 0 /* fp_abi (Val_GNU_MIPS_ABI_FP_ANY) */
+ .word 0 /* isa_ext */
+ .word 0 /* ases */
+ .word 0 /* flags1 */
+ .word 0 /* flags2 */
diff --git a/arch/mips/vdso/genvdso.c b/arch/mips/vdso/genvdso.c
new file mode 100644
index 000000000000..530a36f465ce
--- /dev/null
+++ b/arch/mips/vdso/genvdso.c
@@ -0,0 +1,293 @@
+/*
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+/*
+ * This tool is used to generate the real VDSO images from the raw image. It
+ * first patches up the MIPS ABI flags and GNU attributes sections defined in
+ * elf.S to have the correct name and type. It then generates a C source file
+ * to be compiled into the kernel containing the VDSO image data and a
+ * mips_vdso_image struct for it, including symbol offsets extracted from the
+ * image.
+ *
+ * We need to be passed both a stripped and unstripped VDSO image. The stripped
+ * image is compiled into the kernel, but we must also patch up the unstripped
+ * image's ABI flags sections so that it can be installed and used for
+ * debugging.
+ */
+
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <byteswap.h>
+#include <elf.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+/* Define these in case the system elf.h is not new enough to have them. */
+#ifndef SHT_GNU_ATTRIBUTES
+# define SHT_GNU_ATTRIBUTES 0x6ffffff5
+#endif
+#ifndef SHT_MIPS_ABIFLAGS
+# define SHT_MIPS_ABIFLAGS 0x7000002a
+#endif
+
+enum {
+ ABI_O32 = (1 << 0),
+ ABI_N32 = (1 << 1),
+ ABI_N64 = (1 << 2),
+
+ ABI_ALL = ABI_O32 | ABI_N32 | ABI_N64,
+};
+
+/* Symbols the kernel requires offsets for. */
+static struct {
+ const char *name;
+ const char *offset_name;
+ unsigned int abis;
+} vdso_symbols[] = {
+ { "__vdso_sigreturn", "off_sigreturn", ABI_O32 },
+ { "__vdso_rt_sigreturn", "off_rt_sigreturn", ABI_ALL },
+ {}
+};
+
+static const char *program_name;
+static const char *vdso_name;
+static unsigned char elf_class;
+static unsigned int elf_abi;
+static bool need_swap;
+static FILE *out_file;
+
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+# define HOST_ORDER ELFDATA2LSB
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+# define HOST_ORDER ELFDATA2MSB
+#endif
+
+#define BUILD_SWAP(bits) \
+ static uint##bits##_t swap_uint##bits(uint##bits##_t val) \
+ { \
+ return need_swap ? bswap_##bits(val) : val; \
+ }
+
+BUILD_SWAP(16)
+BUILD_SWAP(32)
+BUILD_SWAP(64)
+
+#define __FUNC(name, bits) name##bits
+#define _FUNC(name, bits) __FUNC(name, bits)
+#define FUNC(name) _FUNC(name, ELF_BITS)
+
+#define __ELF(x, bits) Elf##bits##_##x
+#define _ELF(x, bits) __ELF(x, bits)
+#define ELF(x) _ELF(x, ELF_BITS)
+
+/*
+ * Include genvdso.h twice with ELF_BITS defined differently to get functions
+ * for both ELF32 and ELF64.
+ */
+
+#define ELF_BITS 64
+#include "genvdso.h"
+#undef ELF_BITS
+
+#define ELF_BITS 32
+#include "genvdso.h"
+#undef ELF_BITS
+
+static void *map_vdso(const char *path, size_t *_size)
+{
+ int fd;
+ struct stat stat;
+ void *addr;
+ const Elf32_Ehdr *ehdr;
+
+ fd = open(path, O_RDWR);
+ if (fd < 0) {
+ fprintf(stderr, "%s: Failed to open '%s': %s\n", program_name,
+ path, strerror(errno));
+ return NULL;
+ }
+
+ if (fstat(fd, &stat) != 0) {
+ fprintf(stderr, "%s: Failed to stat '%s': %s\n", program_name,
+ path, strerror(errno));
+ return NULL;
+ }
+
+ addr = mmap(NULL, stat.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd,
+ 0);
+ if (addr == MAP_FAILED) {
+ fprintf(stderr, "%s: Failed to map '%s': %s\n", program_name,
+ path, strerror(errno));
+ return NULL;
+ }
+
+ /* ELF32/64 header formats are the same for the bits we're checking. */
+ ehdr = addr;
+
+ if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) != 0) {
+ fprintf(stderr, "%s: '%s' is not an ELF file\n", program_name,
+ path);
+ return NULL;
+ }
+
+ elf_class = ehdr->e_ident[EI_CLASS];
+ switch (elf_class) {
+ case ELFCLASS32:
+ case ELFCLASS64:
+ break;
+ default:
+ fprintf(stderr, "%s: '%s' has invalid ELF class\n",
+ program_name, path);
+ return NULL;
+ }
+
+ switch (ehdr->e_ident[EI_DATA]) {
+ case ELFDATA2LSB:
+ case ELFDATA2MSB:
+ need_swap = ehdr->e_ident[EI_DATA] != HOST_ORDER;
+ break;
+ default:
+ fprintf(stderr, "%s: '%s' has invalid ELF data order\n",
+ program_name, path);
+ return NULL;
+ }
+
+ if (swap_uint16(ehdr->e_machine) != EM_MIPS) {
+ fprintf(stderr,
+ "%s: '%s' has invalid ELF machine (expected EM_MIPS)\n",
+ program_name, path);
+ return NULL;
+ } else if (swap_uint16(ehdr->e_type) != ET_DYN) {
+ fprintf(stderr,
+ "%s: '%s' has invalid ELF type (expected ET_DYN)\n",
+ program_name, path);
+ return NULL;
+ }
+
+ *_size = stat.st_size;
+ return addr;
+}
+
+static bool patch_vdso(const char *path, void *vdso)
+{
+ if (elf_class == ELFCLASS64)
+ return patch_vdso64(path, vdso);
+ else
+ return patch_vdso32(path, vdso);
+}
+
+static bool get_symbols(const char *path, void *vdso)
+{
+ if (elf_class == ELFCLASS64)
+ return get_symbols64(path, vdso);
+ else
+ return get_symbols32(path, vdso);
+}
+
+int main(int argc, char **argv)
+{
+ const char *dbg_vdso_path, *vdso_path, *out_path;
+ void *dbg_vdso, *vdso;
+ size_t dbg_vdso_size, vdso_size, i;
+
+ program_name = argv[0];
+
+ if (argc < 4 || argc > 5) {
+ fprintf(stderr,
+ "Usage: %s <debug VDSO> <stripped VDSO> <output file> [<name>]\n",
+ program_name);
+ return EXIT_FAILURE;
+ }
+
+ dbg_vdso_path = argv[1];
+ vdso_path = argv[2];
+ out_path = argv[3];
+ vdso_name = (argc > 4) ? argv[4] : "";
+
+ dbg_vdso = map_vdso(dbg_vdso_path, &dbg_vdso_size);
+ if (!dbg_vdso)
+ return EXIT_FAILURE;
+
+ vdso = map_vdso(vdso_path, &vdso_size);
+ if (!vdso)
+ return EXIT_FAILURE;
+
+ /* Patch both the VDSOs' ABI flags sections. */
+ if (!patch_vdso(dbg_vdso_path, dbg_vdso))
+ return EXIT_FAILURE;
+ if (!patch_vdso(vdso_path, vdso))
+ return EXIT_FAILURE;
+
+ if (msync(dbg_vdso, dbg_vdso_size, MS_SYNC) != 0) {
+ fprintf(stderr, "%s: Failed to sync '%s': %s\n", program_name,
+ dbg_vdso_path, strerror(errno));
+ return EXIT_FAILURE;
+ } else if (msync(vdso, vdso_size, MS_SYNC) != 0) {
+ fprintf(stderr, "%s: Failed to sync '%s': %s\n", program_name,
+ vdso_path, strerror(errno));
+ return EXIT_FAILURE;
+ }
+
+ out_file = fopen(out_path, "w");
+ if (!out_file) {
+ fprintf(stderr, "%s: Failed to open '%s': %s\n", program_name,
+ out_path, strerror(errno));
+ return EXIT_FAILURE;
+ }
+
+ fprintf(out_file, "/* Automatically generated - do not edit */\n");
+ fprintf(out_file, "#include <linux/linkage.h>\n");
+ fprintf(out_file, "#include <linux/mm.h>\n");
+ fprintf(out_file, "#include <asm/vdso.h>\n");
+
+ /* Write out the stripped VDSO data. */
+ fprintf(out_file,
+ "static unsigned char vdso_data[PAGE_ALIGN(%zu)] __page_aligned_data = {\n\t",
+ vdso_size);
+ for (i = 0; i < vdso_size; i++) {
+ if (!(i % 10))
+ fprintf(out_file, "\n\t");
+ fprintf(out_file, "0x%02x, ", ((unsigned char *)vdso)[i]);
+ }
+ fprintf(out_file, "\n};\n");
+
+ /* Preallocate a page array. */
+ fprintf(out_file,
+ "static struct page *vdso_pages[PAGE_ALIGN(%zu) / PAGE_SIZE];\n",
+ vdso_size);
+
+ fprintf(out_file, "struct mips_vdso_image vdso_image%s%s = {\n",
+ (vdso_name[0]) ? "_" : "", vdso_name);
+ fprintf(out_file, "\t.data = vdso_data,\n");
+ fprintf(out_file, "\t.size = PAGE_ALIGN(%zu),\n", vdso_size);
+ fprintf(out_file, "\t.mapping = {\n");
+ fprintf(out_file, "\t\t.name = \"[vdso]\",\n");
+ fprintf(out_file, "\t\t.pages = vdso_pages,\n");
+ fprintf(out_file, "\t},\n");
+
+ /* Calculate and write symbol offsets to <output file> */
+ if (!get_symbols(dbg_vdso_path, dbg_vdso)) {
+ unlink(out_path);
+ return EXIT_FAILURE;
+ }
+
+ fprintf(out_file, "};\n");
+
+ return EXIT_SUCCESS;
+}
diff --git a/arch/mips/vdso/genvdso.h b/arch/mips/vdso/genvdso.h
new file mode 100644
index 000000000000..94334727059a
--- /dev/null
+++ b/arch/mips/vdso/genvdso.h
@@ -0,0 +1,187 @@
+/*
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+static inline bool FUNC(patch_vdso)(const char *path, void *vdso)
+{
+ const ELF(Ehdr) *ehdr = vdso;
+ void *shdrs;
+ ELF(Shdr) *shdr;
+ char *shstrtab, *name;
+ uint16_t sh_count, sh_entsize, i;
+ unsigned int local_gotno, symtabno, gotsym;
+ ELF(Dyn) *dyn = NULL;
+
+ shdrs = vdso + FUNC(swap_uint)(ehdr->e_shoff);
+ sh_count = swap_uint16(ehdr->e_shnum);
+ sh_entsize = swap_uint16(ehdr->e_shentsize);
+
+ shdr = shdrs + (sh_entsize * swap_uint16(ehdr->e_shstrndx));
+ shstrtab = vdso + FUNC(swap_uint)(shdr->sh_offset);
+
+ for (i = 0; i < sh_count; i++) {
+ shdr = shdrs + (i * sh_entsize);
+ name = shstrtab + swap_uint32(shdr->sh_name);
+
+ /*
+ * Ensure there are no relocation sections - ld.so does not
+ * relocate the VDSO so if there are relocations things will
+ * break.
+ */
+ switch (swap_uint32(shdr->sh_type)) {
+ case SHT_REL:
+ case SHT_RELA:
+ fprintf(stderr,
+ "%s: '%s' contains relocation sections\n",
+ program_name, path);
+ return false;
+ case SHT_DYNAMIC:
+ dyn = vdso + FUNC(swap_uint)(shdr->sh_offset);
+ break;
+ }
+
+ /* Check for existing sections. */
+ if (strcmp(name, ".MIPS.abiflags") == 0) {
+ fprintf(stderr,
+ "%s: '%s' already contains a '.MIPS.abiflags' section\n",
+ program_name, path);
+ return false;
+ }
+
+ if (strcmp(name, ".mips_abiflags") == 0) {
+ strcpy(name, ".MIPS.abiflags");
+ shdr->sh_type = swap_uint32(SHT_MIPS_ABIFLAGS);
+ shdr->sh_entsize = shdr->sh_size;
+ }
+ }
+
+ /*
+ * Ensure the GOT has no entries other than the standard 2, for the same
+ * reason we check that there's no relocation sections above.
+ * The standard two entries are:
+ * - Lazy resolver
+ * - Module pointer
+ */
+ if (dyn) {
+ local_gotno = symtabno = gotsym = 0;
+
+ while (FUNC(swap_uint)(dyn->d_tag) != DT_NULL) {
+ switch (FUNC(swap_uint)(dyn->d_tag)) {
+ /*
+ * This member holds the number of local GOT entries.
+ */
+ case DT_MIPS_LOCAL_GOTNO:
+ local_gotno = FUNC(swap_uint)(dyn->d_un.d_val);
+ break;
+ /*
+ * This member holds the number of entries in the
+ * .dynsym section.
+ */
+ case DT_MIPS_SYMTABNO:
+ symtabno = FUNC(swap_uint)(dyn->d_un.d_val);
+ break;
+ /*
+ * This member holds the index of the first dynamic
+ * symbol table entry that corresponds to an entry in
+ * the GOT.
+ */
+ case DT_MIPS_GOTSYM:
+ gotsym = FUNC(swap_uint)(dyn->d_un.d_val);
+ break;
+ }
+
+ dyn++;
+ }
+
+ if (local_gotno > 2 || symtabno - gotsym) {
+ fprintf(stderr,
+ "%s: '%s' contains unexpected GOT entries\n",
+ program_name, path);
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static inline bool FUNC(get_symbols)(const char *path, void *vdso)
+{
+ const ELF(Ehdr) *ehdr = vdso;
+ void *shdrs, *symtab;
+ ELF(Shdr) *shdr;
+ const ELF(Sym) *sym;
+ char *strtab, *name;
+ uint16_t sh_count, sh_entsize, st_count, st_entsize, i, j;
+ uint64_t offset;
+ uint32_t flags;
+
+ shdrs = vdso + FUNC(swap_uint)(ehdr->e_shoff);
+ sh_count = swap_uint16(ehdr->e_shnum);
+ sh_entsize = swap_uint16(ehdr->e_shentsize);
+
+ for (i = 0; i < sh_count; i++) {
+ shdr = shdrs + (i * sh_entsize);
+
+ if (swap_uint32(shdr->sh_type) == SHT_SYMTAB)
+ break;
+ }
+
+ if (i == sh_count) {
+ fprintf(stderr, "%s: '%s' has no symbol table\n", program_name,
+ path);
+ return false;
+ }
+
+ /* Get flags */
+ flags = swap_uint32(ehdr->e_flags);
+ if (elf_class == ELFCLASS64)
+ elf_abi = ABI_N64;
+ else if (flags & EF_MIPS_ABI2)
+ elf_abi = ABI_N32;
+ else
+ elf_abi = ABI_O32;
+
+ /* Get symbol table. */
+ symtab = vdso + FUNC(swap_uint)(shdr->sh_offset);
+ st_entsize = FUNC(swap_uint)(shdr->sh_entsize);
+ st_count = FUNC(swap_uint)(shdr->sh_size) / st_entsize;
+
+ /* Get string table. */
+ shdr = shdrs + (swap_uint32(shdr->sh_link) * sh_entsize);
+ strtab = vdso + FUNC(swap_uint)(shdr->sh_offset);
+
+ /* Write offsets for symbols needed by the kernel. */
+ for (i = 0; vdso_symbols[i].name; i++) {
+ if (!(vdso_symbols[i].abis & elf_abi))
+ continue;
+
+ for (j = 0; j < st_count; j++) {
+ sym = symtab + (j * st_entsize);
+ name = strtab + swap_uint32(sym->st_name);
+
+ if (!strcmp(name, vdso_symbols[i].name)) {
+ offset = FUNC(swap_uint)(sym->st_value);
+
+ fprintf(out_file,
+ "\t.%s = 0x%" PRIx64 ",\n",
+ vdso_symbols[i].offset_name, offset);
+ break;
+ }
+ }
+
+ if (j == st_count) {
+ fprintf(stderr,
+ "%s: '%s' is missing required symbol '%s'\n",
+ program_name, path, vdso_symbols[i].name);
+ return false;
+ }
+ }
+
+ return true;
+}
diff --git a/arch/mips/vdso/sigreturn.S b/arch/mips/vdso/sigreturn.S
new file mode 100644
index 000000000000..715bf5993529
--- /dev/null
+++ b/arch/mips/vdso/sigreturn.S
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include "vdso.h"
+
+#include <uapi/asm/unistd.h>
+
+#include <asm/regdef.h>
+#include <asm/asm.h>
+
+ .section .text
+ .cfi_sections .debug_frame
+
+LEAF(__vdso_rt_sigreturn)
+ .cfi_startproc
+ .frame sp, 0, ra
+ .mask 0x00000000, 0
+ .fmask 0x00000000, 0
+ .cfi_signal_frame
+
+ li v0, __NR_rt_sigreturn
+ syscall
+
+ .cfi_endproc
+ END(__vdso_rt_sigreturn)
+
+#if _MIPS_SIM == _MIPS_SIM_ABI32
+
+LEAF(__vdso_sigreturn)
+ .cfi_startproc
+ .frame sp, 0, ra
+ .mask 0x00000000, 0
+ .fmask 0x00000000, 0
+ .cfi_signal_frame
+
+ li v0, __NR_sigreturn
+ syscall
+
+ .cfi_endproc
+ END(__vdso_sigreturn)
+
+#endif
diff --git a/arch/mips/vdso/vdso.h b/arch/mips/vdso/vdso.h
new file mode 100644
index 000000000000..0bb6b1adc385
--- /dev/null
+++ b/arch/mips/vdso/vdso.h
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <asm/sgidefs.h>
+
+#if _MIPS_SIM != _MIPS_SIM_ABI64 && defined(CONFIG_64BIT)
+
+/* Building 32-bit VDSO for the 64-bit kernel. Fake a 32-bit Kconfig. */
+#undef CONFIG_64BIT
+#define CONFIG_32BIT 1
+#ifndef __ASSEMBLY__
+#include <asm-generic/atomic64.h>
+#endif
+#endif
+
+#ifndef __ASSEMBLY__
+
+#include <asm/asm.h>
+#include <asm/page.h>
+#include <asm/vdso.h>
+
+static inline unsigned long get_vdso_base(void)
+{
+ unsigned long addr;
+
+ /*
+ * We can't use cpu_has_mips_r6 since it needs the cpu_data[]
+ * kernel symbol.
+ */
+#ifdef CONFIG_CPU_MIPSR6
+ /*
+ * lapc <symbol> is an alias to addiupc reg, <symbol> - .
+ *
+ * We can't use addiupc because there is no label-label
+ * support for the addiupc reloc
+ */
+ __asm__("lapc %0, _start \n"
+ : "=r" (addr) : :);
+#else
+ /*
+ * Get the base load address of the VDSO. We have to avoid generating
+ * relocations and references to the GOT because ld.so does not peform
+ * relocations on the VDSO. We use the current offset from the VDSO base
+ * and perform a PC-relative branch which gives the absolute address in
+ * ra, and take the difference. The assembler chokes on
+ * "li %0, _start - .", so embed the offset as a word and branch over
+ * it.
+ *
+ */
+
+ __asm__(
+ " .set push \n"
+ " .set noreorder \n"
+ " bal 1f \n"
+ " nop \n"
+ " .word _start - . \n"
+ "1: lw %0, 0($31) \n"
+ " " STR(PTR_ADDU) " %0, $31, %0 \n"
+ " .set pop \n"
+ : "=r" (addr)
+ :
+ : "$31");
+#endif /* CONFIG_CPU_MIPSR6 */
+
+ return addr;
+}
+
+static inline const union mips_vdso_data *get_vdso_data(void)
+{
+ return (const union mips_vdso_data *)(get_vdso_base() - PAGE_SIZE);
+}
+
+#endif /* __ASSEMBLY__ */
diff --git a/arch/mips/vdso/vdso.lds.S b/arch/mips/vdso/vdso.lds.S
new file mode 100644
index 000000000000..21655b6fefc5
--- /dev/null
+++ b/arch/mips/vdso/vdso.lds.S
@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <asm/sgidefs.h>
+
+#if _MIPS_SIM == _MIPS_SIM_ABI64
+OUTPUT_FORMAT("elf64-tradlittlemips", "elf64-tradbigmips", "elf64-tradlittlemips")
+#elif _MIPS_SIM == _MIPS_SIM_NABI32
+OUTPUT_FORMAT("elf32-ntradlittlemips", "elf32-ntradbigmips", "elf32-ntradlittlemips")
+#else
+OUTPUT_FORMAT("elf32-tradlittlemips", "elf32-tradbigmips", "elf32-tradlittlemips")
+#endif
+
+OUTPUT_ARCH(mips)
+
+SECTIONS
+{
+ PROVIDE(_start = .);
+ . = SIZEOF_HEADERS;
+
+ /*
+ * In order to retain compatibility with older toolchains we provide the
+ * ABI flags section ourself. Newer assemblers will automatically
+ * generate .MIPS.abiflags sections so we discard such input sections,
+ * and then manually define our own section here. genvdso will patch
+ * this section to have the correct name/type.
+ */
+ .mips_abiflags : { *(.mips_abiflags) } :text :abiflags
+
+ .reginfo : { *(.reginfo) } :text :reginfo
+
+ .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
+
+ .text : { *(.text*) } :text
+ 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/ : {
+ *(.MIPS.abiflags)
+ *(.gnu.attributes)
+ *(.note.GNU-stack)
+ *(.data .data.* .gnu.linkonce.d.* .sdata*)
+ *(.bss .sbss .dynbss .dynsbss)
+ }
+}
+
+PHDRS
+{
+ /*
+ * Provide a PT_MIPS_ABIFLAGS header to assign the ABI flags section
+ * to. We can specify the header type directly here so no modification
+ * is needed later on.
+ */
+ abiflags 0x70000003;
+
+ /*
+ * The ABI flags header must exist directly after the PT_INTERP header,
+ * so we must explicitly place the PT_MIPS_REGINFO header after it to
+ * stop the linker putting one in at the start.
+ */
+ reginfo 0x70000000;
+
+ 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;
+}
+
+VERSION
+{
+ LINUX_2.6 {
+ local: *;
+ };
+}
--
2.6.2
