mirror of https://gitee.com/openkylin/linux.git
MIPS: Initial implementation of a VDSO
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@imgtec.com:
- 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]
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11337/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Alex Smith
Ralf Baechle
parent
22773aa9b9
commit
ebb5e78cc6
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@ -17,6 +17,7 @@ obj- := $(platform-)
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obj-y += kernel/
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obj-y += mm/
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obj-y += net/
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obj-y += vdso/
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ifdef CONFIG_KVM
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obj-y += kvm/
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@ -11,19 +11,20 @@
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#include <asm/signal.h>
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#include <asm/siginfo.h>
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#include <asm/vdso.h>
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struct mips_abi {
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int (* const setup_frame)(void *sig_return, struct ksignal *ksig,
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struct pt_regs *regs, sigset_t *set);
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const unsigned long signal_return_offset;
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int (* const setup_rt_frame)(void *sig_return, struct ksignal *ksig,
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struct pt_regs *regs, sigset_t *set);
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const unsigned long rt_signal_return_offset;
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const unsigned long restart;
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unsigned off_sc_fpregs;
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unsigned off_sc_fpc_csr;
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unsigned off_sc_used_math;
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struct mips_vdso_image *vdso;
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};
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#endif /* _ASM_ABI_H */
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@ -8,6 +8,7 @@
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#ifndef _ASM_ELF_H
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#define _ASM_ELF_H
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#include <linux/auxvec.h>
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#include <linux/fs.h>
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#include <uapi/linux/elf.h>
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@ -419,6 +420,12 @@ extern const char *__elf_platform;
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#define ELF_ET_DYN_BASE (TASK_SIZE / 3 * 2)
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#endif
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#define ARCH_DLINFO \
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do { \
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NEW_AUX_ENT(AT_SYSINFO_EHDR, \
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(unsigned long)current->mm->context.vdso); \
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} while (0)
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#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
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struct linux_binprm;
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extern int arch_setup_additional_pages(struct linux_binprm *bprm,
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@ -36,12 +36,6 @@ extern unsigned int vced_count, vcei_count;
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*/
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#define HAVE_ARCH_PICK_MMAP_LAYOUT 1
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/*
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* A special page (the vdso) is mapped into all processes at the very
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* top of the virtual memory space.
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*/
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#define SPECIAL_PAGES_SIZE PAGE_SIZE
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#ifdef CONFIG_32BIT
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#ifdef CONFIG_KVM_GUEST
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/* User space process size is limited to 1GB in KVM Guest Mode */
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@ -80,7 +74,7 @@ extern unsigned int vced_count, vcei_count;
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#endif
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#define STACK_TOP ((TASK_SIZE & PAGE_MASK) - SPECIAL_PAGES_SIZE)
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#define STACK_TOP (TASK_SIZE & PAGE_MASK)
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/*
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* This decides where the kernel will search for a free chunk of vm
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@ -1,29 +1,70 @@
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/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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* Copyright (C) 2015 Imagination Technologies
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* Author: Alex Smith <alex.smith@imgtec.com>
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*
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* Copyright (C) 2009 Cavium Networks
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#ifndef __ASM_VDSO_H
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#define __ASM_VDSO_H
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#include <linux/types.h>
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#include <linux/mm_types.h>
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/**
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* struct mips_vdso_image - Details of a VDSO image.
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* @data: Pointer to VDSO image data (page-aligned).
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* @size: Size of the VDSO image data (page-aligned).
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* @off_sigreturn: Offset of the sigreturn() trampoline.
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* @off_rt_sigreturn: Offset of the rt_sigreturn() trampoline.
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* @mapping: Special mapping structure.
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*
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* This structure contains details of a VDSO image, including the image data
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* and offsets of certain symbols required by the kernel. It is generated as
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* part of the VDSO build process, aside from the mapping page array, which is
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* populated at runtime.
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*/
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struct mips_vdso_image {
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void *data;
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unsigned long size;
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#ifdef CONFIG_32BIT
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struct mips_vdso {
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u32 signal_trampoline[2];
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u32 rt_signal_trampoline[2];
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unsigned long off_sigreturn;
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unsigned long off_rt_sigreturn;
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struct vm_special_mapping mapping;
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};
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#else /* !CONFIG_32BIT */
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struct mips_vdso {
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u32 o32_signal_trampoline[2];
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u32 o32_rt_signal_trampoline[2];
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u32 rt_signal_trampoline[2];
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u32 n32_rt_signal_trampoline[2];
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/*
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* The following structures are auto-generated as part of the build for each
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* ABI by genvdso, see arch/mips/vdso/Makefile.
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*/
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extern struct mips_vdso_image vdso_image;
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#ifdef CONFIG_MIPS32_O32
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extern struct mips_vdso_image vdso_image_o32;
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#endif
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#ifdef CONFIG_MIPS32_N32
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extern struct mips_vdso_image vdso_image_n32;
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#endif
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/**
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* union mips_vdso_data - Data provided by the kernel for the VDSO.
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*
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* This structure contains data needed by functions within the VDSO. It is
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* populated by the kernel and mapped read-only into user memory.
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*
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* Note: Care should be taken when modifying as the layout must remain the same
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* for both 64- and 32-bit (for 32-bit userland on 64-bit kernel).
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*/
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union mips_vdso_data {
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struct {
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};
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u8 page[PAGE_SIZE];
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};
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#endif /* CONFIG_32BIT */
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#endif /* __ASM_VDSO_H */
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@ -1,9 +1,9 @@
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# UAPI Header export list
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include include/uapi/asm-generic/Kbuild.asm
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generic-y += auxvec.h
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generic-y += ipcbuf.h
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header-y += auxvec.h
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header-y += bitfield.h
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header-y += bitsperlong.h
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header-y += break.h
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@ -0,0 +1,17 @@
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/*
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* Copyright (C) 2015 Imagination Technologies
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* Author: Alex Smith <alex.smith@imgtec.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#ifndef __ASM_AUXVEC_H
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#define __ASM_AUXVEC_H
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/* Location of VDSO image. */
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#define AT_SYSINFO_EHDR 33
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#endif /* __ASM_AUXVEC_H */
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#include <asm/ucontext.h>
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#include <asm/cpu-features.h>
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#include <asm/war.h>
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#include <asm/vdso.h>
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#include <asm/dsp.h>
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#include <asm/inst.h>
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#include <asm/msa.h>
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@ -752,16 +751,15 @@ static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
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struct mips_abi mips_abi = {
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#ifdef CONFIG_TRAD_SIGNALS
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.setup_frame = setup_frame,
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.signal_return_offset = offsetof(struct mips_vdso, signal_trampoline),
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#endif
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.setup_rt_frame = setup_rt_frame,
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.rt_signal_return_offset =
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offsetof(struct mips_vdso, rt_signal_trampoline),
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.restart = __NR_restart_syscall,
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.off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
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.off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
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.off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
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.vdso = &vdso_image,
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};
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static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
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@ -801,11 +799,11 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
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}
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if (sig_uses_siginfo(&ksig->ka))
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ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset,
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ret = abi->setup_rt_frame(vdso + abi->vdso->off_rt_sigreturn,
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ksig, regs, oldset);
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else
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ret = abi->setup_frame(vdso + abi->signal_return_offset, ksig,
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regs, oldset);
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ret = abi->setup_frame(vdso + abi->vdso->off_sigreturn,
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ksig, regs, oldset);
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signal_setup_done(ret, ksig, 0);
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}
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@ -31,7 +31,6 @@
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#include <asm/ucontext.h>
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#include <asm/fpu.h>
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#include <asm/war.h>
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#include <asm/vdso.h>
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#include <asm/dsp.h>
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#include "signal-common.h"
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@ -406,14 +405,12 @@ static int setup_rt_frame_32(void *sig_return, struct ksignal *ksig,
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*/
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struct mips_abi mips_abi_32 = {
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.setup_frame = setup_frame_32,
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.signal_return_offset =
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offsetof(struct mips_vdso, o32_signal_trampoline),
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.setup_rt_frame = setup_rt_frame_32,
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.rt_signal_return_offset =
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offsetof(struct mips_vdso, o32_rt_signal_trampoline),
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.restart = __NR_O32_restart_syscall,
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.off_sc_fpregs = offsetof(struct sigcontext32, sc_fpregs),
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.off_sc_fpc_csr = offsetof(struct sigcontext32, sc_fpc_csr),
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.off_sc_used_math = offsetof(struct sigcontext32, sc_used_math),
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.vdso = &vdso_image_o32,
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};
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@ -38,7 +38,6 @@
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#include <asm/fpu.h>
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#include <asm/cpu-features.h>
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#include <asm/war.h>
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#include <asm/vdso.h>
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#include "signal-common.h"
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@ -151,11 +150,11 @@ static int setup_rt_frame_n32(void *sig_return, struct ksignal *ksig,
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struct mips_abi mips_abi_n32 = {
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.setup_rt_frame = setup_rt_frame_n32,
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.rt_signal_return_offset =
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offsetof(struct mips_vdso, n32_rt_signal_trampoline),
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.restart = __NR_N32_restart_syscall,
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.off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
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.off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
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.off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
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.vdso = &vdso_image_n32,
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};
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@ -1,122 +1,116 @@
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/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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* Copyright (C) 2015 Imagination Technologies
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* Author: Alex Smith <alex.smith@imgtec.com>
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*
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* Copyright (C) 2009, 2010 Cavium Networks, Inc.
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/err.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/init.h>
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#include <linux/binfmts.h>
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#include <linux/elf.h>
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#include <linux/vmalloc.h>
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#include <linux/unistd.h>
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#include <linux/random.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <asm/abi.h>
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#include <asm/vdso.h>
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#include <asm/uasm.h>
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#include <asm/processor.h>
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/* Kernel-provided data used by the VDSO. */
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static union mips_vdso_data vdso_data __page_aligned_data;
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/*
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* Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
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* Mapping for the VDSO data pages. The real pages are mapped manually, as
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* what we map and where within the area they are mapped is determined at
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* runtime.
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*/
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#define __NR_O32_sigreturn 4119
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#define __NR_O32_rt_sigreturn 4193
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#define __NR_N32_rt_sigreturn 6211
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static struct page *no_pages[] = { NULL };
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static struct vm_special_mapping vdso_vvar_mapping = {
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.name = "[vvar]",
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.pages = no_pages,
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};
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|
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static struct page *vdso_page;
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static void __init install_trampoline(u32 *tramp, unsigned int sigreturn)
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static void __init init_vdso_image(struct mips_vdso_image *image)
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{
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uasm_i_addiu(&tramp, 2, 0, sigreturn); /* li v0, sigreturn */
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uasm_i_syscall(&tramp, 0);
|
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unsigned long num_pages, i;
|
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|
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BUG_ON(!PAGE_ALIGNED(image->data));
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BUG_ON(!PAGE_ALIGNED(image->size));
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num_pages = image->size / PAGE_SIZE;
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for (i = 0; i < num_pages; i++) {
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image->mapping.pages[i] =
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virt_to_page(image->data + (i * PAGE_SIZE));
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}
|
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}
|
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|
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static int __init init_vdso(void)
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{
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struct mips_vdso *vdso;
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init_vdso_image(&vdso_image);
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|
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vdso_page = alloc_page(GFP_KERNEL);
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if (!vdso_page)
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panic("Cannot allocate vdso");
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vdso = vmap(&vdso_page, 1, 0, PAGE_KERNEL);
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if (!vdso)
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panic("Cannot map vdso");
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clear_page(vdso);
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install_trampoline(vdso->rt_signal_trampoline, __NR_rt_sigreturn);
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#ifdef CONFIG_32BIT
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install_trampoline(vdso->signal_trampoline, __NR_sigreturn);
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#else
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install_trampoline(vdso->n32_rt_signal_trampoline,
|
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__NR_N32_rt_sigreturn);
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install_trampoline(vdso->o32_signal_trampoline, __NR_O32_sigreturn);
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install_trampoline(vdso->o32_rt_signal_trampoline,
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__NR_O32_rt_sigreturn);
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#ifdef CONFIG_MIPS32_O32
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init_vdso_image(&vdso_image_o32);
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#endif
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|
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vunmap(vdso);
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#ifdef CONFIG_MIPS32_N32
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init_vdso_image(&vdso_image_n32);
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#endif
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return 0;
|
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}
|
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subsys_initcall(init_vdso);
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|
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static unsigned long vdso_addr(unsigned long start)
|
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{
|
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unsigned long offset = 0UL;
|
||||
|
||||
if (current->flags & PF_RANDOMIZE) {
|
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offset = get_random_int();
|
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offset <<= PAGE_SHIFT;
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if (TASK_IS_32BIT_ADDR)
|
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offset &= 0xfffffful;
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||||
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;
|
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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;
|
||||
|
||||
mm->context.vdso = (void *)addr;
|
||||
/* 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;
|
||||
}
|
||||
|
||||
up_fail:
|
||||
mm->context.vdso = (void *)vdso_addr;
|
||||
ret = 0;
|
||||
|
||||
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;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -0,0 +1,4 @@
|
|||
*.so*
|
||||
vdso-*image.c
|
||||
genvdso
|
||||
vdso*.lds
|
||||
|
|
@ -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...
|
||||
|
|
@ -0,0 +1,68 @@
|
|||
/*
|
||||
* Copyright (C) 2015 Imagination Technologies
|
||||
* Author: Alex Smith <alex.smith@imgtec.com>
|
||||
*
|
||||
* 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 */
|
||||
|
|
@ -0,0 +1,293 @@
|
|||
/*
|
||||
* Copyright (C) 2015 Imagination Technologies
|
||||
* Author: Alex Smith <alex.smith@imgtec.com>
|
||||
*
|
||||
* 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;
|
||||
}
|
||||
|
|
@ -0,0 +1,187 @@
|
|||
/*
|
||||
* Copyright (C) 2015 Imagination Technologies
|
||||
* Author: Alex Smith <alex.smith@imgtec.com>
|
||||
*
|
||||
* 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;
|
||||
}
|
||||
|
|
@ -0,0 +1,49 @@
|
|||
/*
|
||||
* Copyright (C) 2015 Imagination Technologies
|
||||
* Author: Alex Smith <alex.smith@imgtec.com>
|
||||
*
|
||||
* 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
|
||||
|
|
@ -0,0 +1,80 @@
|
|||
/*
|
||||
* Copyright (C) 2015 Imagination Technologies
|
||||
* Author: Alex Smith <alex.smith@imgtec.com>
|
||||
*
|
||||
* 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__ */
|
||||
|
|
@ -0,0 +1,100 @@
|
|||
/*
|
||||
* Copyright (C) 2015 Imagination Technologies
|
||||
* Author: Alex Smith <alex.smith@imgtec.com>
|
||||
*
|
||||
* 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: *;
|
||||
};
|
||||
}
|
||||
Loading…
Reference in New Issue