From 768fe76e92477870ab14399dbc6bb8d801621c5c Mon Sep 17 00:00:00 2001 From: YunQiang Su Date: Tue, 20 Feb 2018 18:33:05 +0100 Subject: linux-user: introduce functions to detect CPU type Add a function to return ELF e_flags and use it to select the CPU model. Signed-off-by: YunQiang Su [lv: split the patch and some cleanup in get_elf_eflags()] Signed-off-by: Laurent Vivier Reviewed-by: Richard Henderson Message-Id: <20180220173307.25125-3-laurent@vivier.eu> --- linux-user/elfload.c | 35 +++++++++++++++++++++++++++++++++++ linux-user/main.c | 20 ++++++++++---------- linux-user/qemu.h | 1 + 3 files changed, 46 insertions(+), 10 deletions(-) (limited to 'linux-user') diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 8bb9a2c3e8..0208022445 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -2396,6 +2396,41 @@ give_up: g_free(syms); } +uint32_t get_elf_eflags(int fd) +{ + struct elfhdr ehdr; + off_t offset; + int ret; + + /* Read ELF header */ + offset = lseek(fd, 0, SEEK_SET); + if (offset == (off_t) -1) { + return 0; + } + ret = read(fd, &ehdr, sizeof(ehdr)); + if (ret < sizeof(ehdr)) { + return 0; + } + offset = lseek(fd, offset, SEEK_SET); + if (offset == (off_t) -1) { + return 0; + } + + /* Check ELF signature */ + if (!elf_check_ident(&ehdr)) { + return 0; + } + + /* check header */ + bswap_ehdr(&ehdr); + if (!elf_check_ehdr(&ehdr)) { + return 0; + } + + /* return architecture id */ + return ehdr.e_flags; +} + int load_elf_binary(struct linux_binprm *bprm, struct image_info *info) { struct image_info interp_info; diff --git a/linux-user/main.c b/linux-user/main.c index 079b98235b..bbeb78fb89 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -4344,8 +4344,17 @@ int main(int argc, char **argv, char **envp) init_qemu_uname_release(); + execfd = qemu_getauxval(AT_EXECFD); + if (execfd == 0) { + execfd = open(filename, O_RDONLY); + if (execfd < 0) { + printf("Error while loading %s: %s\n", filename, strerror(errno)); + _exit(EXIT_FAILURE); + } + } + if (cpu_model == NULL) { - cpu_model = cpu_get_model(0); + cpu_model = cpu_get_model(get_elf_eflags(execfd)); } tcg_exec_init(0); /* NOTE: we need to init the CPU at this stage to get @@ -4438,15 +4447,6 @@ int main(int argc, char **argv, char **envp) cpu->opaque = ts; task_settid(ts); - execfd = qemu_getauxval(AT_EXECFD); - if (execfd == 0) { - execfd = open(filename, O_RDONLY); - if (execfd < 0) { - printf("Error while loading %s: %s\n", filename, strerror(errno)); - _exit(EXIT_FAILURE); - } - } - ret = loader_exec(execfd, filename, target_argv, target_environ, regs, info, &bprm); if (ret != 0) { diff --git a/linux-user/qemu.h b/linux-user/qemu.h index bc4bf35036..f4b4ca72ad 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -186,6 +186,7 @@ int loader_exec(int fdexec, const char *filename, char **argv, char **envp, struct target_pt_regs * regs, struct image_info *infop, struct linux_binprm *); +uint32_t get_elf_eflags(int fd); int load_elf_binary(struct linux_binprm *bprm, struct image_info *info); int load_flt_binary(struct linux_binprm *bprm, struct image_info *info); -- cgit v1.2.3