From: Richard Henderson Date: Thu, 17 Jun 2021 21:39:14 +0000 (-0700) Subject: linux-user/x86_64: Add vdso X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=6b1a9d38b570d6b2812711cfadb6eb60ed3a709d;p=qmiga%2Fqemu.git linux-user/x86_64: Add vdso Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 46f73a4166..62a33481e1 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -318,10 +318,10 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUX86State *en } \ } while (0) -#define VDSO_HEADER "vdso.c.inc" - #endif /* TARGET_X86_64 */ +#define VDSO_HEADER "vdso.c.inc" + #define USE_ELF_CORE_DUMP #define ELF_EXEC_PAGESIZE 4096 diff --git a/linux-user/x86_64/Makefile.vdso b/linux-user/x86_64/Makefile.vdso new file mode 100644 index 0000000000..26552b66db --- /dev/null +++ b/linux-user/x86_64/Makefile.vdso @@ -0,0 +1,11 @@ +include $(BUILD_DIR)/tests/tcg/x86_64-linux-user/config-target.mak + +SUBDIR = $(SRC_PATH)/linux-user/x86_64 +VPATH += $(SUBDIR) + +all: $(SUBDIR)/vdso.so + +$(SUBDIR)/vdso.so: vdso.S vdso.ld + $(CC) -o $@ -nostdlib -shared -Wl,-h,linux-vdso.so.1 \ + -Wl,--build-id=sha1 -Wl,--hash-style=both \ + -Wl,-T,$(SUBDIR)/vdso.ld $< diff --git a/linux-user/x86_64/meson.build b/linux-user/x86_64/meson.build index 203af9a60c..8c60da7a60 100644 --- a/linux-user/x86_64/meson.build +++ b/linux-user/x86_64/meson.build @@ -3,3 +3,7 @@ syscall_nr_generators += { arguments: [ meson.current_source_dir() / 'syscallhdr.sh', '@INPUT@', '@OUTPUT@', '@EXTRA_ARGS@' ], output: '@BASENAME@_nr.h') } + +vdso_inc = gen_vdso.process('vdso.so') + +linux_user_ss.add(when: 'TARGET_X86_64', if_true: vdso_inc) diff --git a/linux-user/x86_64/vdso.S b/linux-user/x86_64/vdso.S new file mode 100644 index 0000000000..47d16c00ab --- /dev/null +++ b/linux-user/x86_64/vdso.S @@ -0,0 +1,78 @@ +/* + * x86-64 linux replacement vdso. + * + * Copyright 2023 Linaro, Ltd. + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include + +.macro endf name + .globl \name + .type \name, @function + .size \name, . - \name +.endm + +.macro weakalias name +\name = __vdso_\name + .weak \name +.endm + +.macro vdso_syscall name, nr +__vdso_\name: + mov $\nr, %eax + syscall + ret +endf __vdso_\name +weakalias \name +.endm + + .cfi_startproc + +vdso_syscall clock_gettime, __NR_clock_gettime +vdso_syscall clock_getres, __NR_clock_getres +vdso_syscall gettimeofday, __NR_gettimeofday +vdso_syscall time, __NR_time + +__vdso_getcpu: + /* + * There is no syscall number for this allocated on x64. + * We can handle this several ways: + * + * (1) Invent a syscall number for use within qemu. + * It should be easy enough to pick a number that + * is well out of the way of the kernel numbers. + * + * (2) Force the emulated cpu to support the rdtscp insn, + * and initialize the TSC_AUX value the appropriate value. + * + * (3) Pretend that we're always running on cpu 0. + * + * This last is the one that's implemented here, with the + * tiny bit of extra code to support rdtscp in place. + */ + xor %ecx, %ecx /* rdtscp w/ tsc_aux = 0 */ + + /* if (cpu != NULL) *cpu = (ecx & 0xfff); */ + test %rdi, %rdi + jz 1f + mov %ecx, %eax + and $0xfff, %eax + mov %eax, (%rdi) + + /* if (node != NULL) *node = (ecx >> 12); */ +1: test %rsi, %rsi + jz 2f + shr $12, %ecx + mov %ecx, (%rsi) + +2: xor %eax, %eax + ret +endf __vdso_getcpu + +weakalias getcpu + + .cfi_endproc + +/* TODO: Add elf note for LINUX_VERSION_CODE */ diff --git a/linux-user/x86_64/vdso.ld b/linux-user/x86_64/vdso.ld new file mode 100644 index 0000000000..ca6001cc3c --- /dev/null +++ b/linux-user/x86_64/vdso.ld @@ -0,0 +1,73 @@ +/* + * Linker script for linux x86-64 replacement vdso. + * + * Copyright 2023 Linaro, Ltd. + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +VERSION { + LINUX_2.6 { + global: + clock_gettime; + __vdso_clock_gettime; + gettimeofday; + __vdso_gettimeofday; + getcpu; + __vdso_getcpu; + time; + __vdso_time; + clock_getres; + __vdso_clock_getres; + + local: *; + }; +} + + +PHDRS { + phdr PT_PHDR FLAGS(4) PHDRS; + load PT_LOAD FLAGS(7) FILEHDR PHDRS; /* FLAGS=RWX */ + dynamic PT_DYNAMIC FLAGS(4); + eh_frame_hdr PT_GNU_EH_FRAME; + note PT_NOTE FLAGS(4); +} + +SECTIONS { + . = SIZEOF_HEADERS; + + /* + * The following, including the FILEHDRS and PHDRS, are modified + * when we relocate the binary. We want them to be initially + * writable for the relocation; we'll force them read-only after. + */ + .note : { *(.note*) } :load :note + .dynamic : { *(.dynamic) } :load :dynamic + .dynsym : { *(.dynsym) } :load + .data : { + /* + * There ought not be any real read-write data. + * But since we manipulated the segment layout, + * we have to put these sections somewhere. + */ + *(.data*) + *(.sdata*) + *(.got.plt) *(.got) + *(.gnu.linkonce.d.*) + *(.bss*) + *(.dynbss*) + *(.gnu.linkonce.b.*) + } + + .rodata : { *(.rodata*) } + .hash : { *(.hash) } + .gnu.hash : { *(.gnu.hash) } + .dynstr : { *(.dynstr) } + .gnu.version : { *(.gnu.version) } + .gnu.version_d : { *(.gnu.version_d) } + .gnu.version_r : { *(.gnu.version_r) } + .eh_frame_hdr : { *(.eh_frame_hdr) } :load :eh_frame_hdr + .eh_frame : { *(.eh_frame) } :load + + .text : { *(.text*) } :load =0x90909090 +} diff --git a/linux-user/x86_64/vdso.so b/linux-user/x86_64/vdso.so new file mode 100755 index 0000000000..c873d6ea58 Binary files /dev/null and b/linux-user/x86_64/vdso.so differ