From e6e102b972c5228d9d50b3208b83b025ccfd1455 Mon Sep 17 00:00:00 2001 From: Doug Rabson Date: Thu, 8 Dec 2022 14:21:52 +0000 Subject: bsd-user: Simplify the implementation of execve This removes the logic which prepends the emulator to each call to execve and fexecve. This is not necessary with the existing imgact_binmisc support and it avoids the need to install the emulator binary into jail environments when using 'binmiscctl --pre-open'. Signed-off-by: Doug Rabson Reviewed-by: Warner Losh Signed-off-by: Warner Losh Acked-by: Richard Henderson --- bsd-user/freebsd/os-proc.c | 118 ++------------------------------------------- bsd-user/main.c | 18 ------- 2 files changed, 3 insertions(+), 133 deletions(-) diff --git a/bsd-user/freebsd/os-proc.c b/bsd-user/freebsd/os-proc.c index e0203e2..bf993f1 100644 --- a/bsd-user/freebsd/os-proc.c +++ b/bsd-user/freebsd/os-proc.c @@ -27,64 +27,12 @@ struct kinfo_proc; #include "qemu.h" /* - * Get the filename for the given file descriptor. - * Note that this may return NULL (fail) if no longer cached in the kernel. - */ -static char * -get_filename_from_fd(pid_t pid, int fd, char *filename, size_t len) -{ - char *ret = NULL; - unsigned int cnt; - struct procstat *procstat = NULL; - struct kinfo_proc *kp = NULL; - struct filestat_list *head = NULL; - struct filestat *fst; - - procstat = procstat_open_sysctl(); - if (procstat == NULL) { - goto out; - } - - kp = procstat_getprocs(procstat, KERN_PROC_PID, pid, &cnt); - if (kp == NULL) { - goto out; - } - - head = procstat_getfiles(procstat, kp, 0); - if (head == NULL) { - goto out; - } - - STAILQ_FOREACH(fst, head, next) { - if (fd == fst->fs_fd) { - if (fst->fs_path != NULL) { - (void)strlcpy(filename, fst->fs_path, len); - ret = filename; - } - break; - } - } - -out: - if (head != NULL) { - procstat_freefiles(procstat, head); - } - if (kp != NULL) { - procstat_freeprocs(procstat, kp); - } - if (procstat != NULL) { - procstat_close(procstat); - } - return ret; -} - -/* * execve/fexecve */ abi_long freebsd_exec_common(abi_ulong path_or_fd, abi_ulong guest_argp, abi_ulong guest_envp, int do_fexec) { - char **argp, **envp, **qargp, **qarg1, **qarg0, **qargend; + char **argp, **envp, **qarg0; int argc, envc; abi_ulong gp; abi_ulong addr; @@ -117,9 +65,7 @@ abi_long freebsd_exec_common(abi_ulong path_or_fd, abi_ulong guest_argp, qarg0 = argp = g_new0(char *, argc + 9); /* save the first argument for the emulator */ *argp++ = (char *)getprogname(); - qargp = argp; *argp++ = (char *)getprogname(); - qarg1 = argp; envp = g_new0(char *, envc + 1); for (gp = guest_argp, q = argp; gp; gp += sizeof(abi_ulong), q++) { if (get_user_ual(addr, gp)) { @@ -137,7 +83,6 @@ abi_long freebsd_exec_common(abi_ulong path_or_fd, abi_ulong guest_argp, total_size += strlen(*q) + 1; } *q++ = NULL; - qargend = q; for (gp = guest_envp, q = envp; gp; gp += sizeof(abi_ulong), q++) { if (get_user_ual(addr, gp)) { @@ -166,71 +111,14 @@ abi_long freebsd_exec_common(abi_ulong path_or_fd, abi_ulong guest_argp, } if (do_fexec) { - if (((int)path_or_fd > 0 && - is_target_elf_binary((int)path_or_fd)) == 1) { - char execpath[PATH_MAX]; - - /* - * The executable is an elf binary for the target - * arch. execve() it using the emulator if we can - * determine the filename path from the fd. - */ - if (get_filename_from_fd(getpid(), (int)path_or_fd, execpath, - sizeof(execpath)) != NULL) { - memmove(qarg1 + 2, qarg1, (qargend - qarg1) * sizeof(*qarg1)); - qarg1[1] = qarg1[0]; - qarg1[0] = (char *)"-0"; - qarg1 += 2; - qargend += 2; - *qarg1 = execpath; -#ifndef DONT_INHERIT_INTERP_PREFIX - memmove(qarg1 + 2, qarg1, (qargend - qarg1) * sizeof(*qarg1)); - *qarg1++ = (char *)"-L"; - *qarg1++ = (char *)interp_prefix; -#endif - ret = get_errno(execve(qemu_proc_pathname, qargp, envp)); - } else { - /* Getting the filename path failed. */ - ret = -TARGET_EBADF; - goto execve_end; - } - } else { - ret = get_errno(fexecve((int)path_or_fd, argp, envp)); - } + ret = get_errno(fexecve((int)path_or_fd, argp, envp)); } else { - int fd; - p = lock_user_string(path_or_fd); if (p == NULL) { ret = -TARGET_EFAULT; goto execve_end; } - - /* - * Check the header and see if it a target elf binary. If so - * then execute using qemu user mode emulator. - */ - fd = open(p, O_RDONLY | O_CLOEXEC); - if (fd > 0 && is_target_elf_binary(fd) == 1) { - close(fd); - /* execve() as a target binary using emulator. */ - memmove(qarg1 + 2, qarg1, (qargend - qarg1) * sizeof(*qarg1)); - qarg1[1] = qarg1[0]; - qarg1[0] = (char *)"-0"; - qarg1 += 2; - qargend += 2; - *qarg1 = (char *)p; -#ifndef DONT_INHERIT_INTERP_PREFIX - memmove(qarg1 + 2, qarg1, (qargend - qarg1) * sizeof(*qarg1)); - *qarg1++ = (char *)"-L"; - *qarg1++ = (char *)interp_prefix; -#endif - ret = get_errno(execve(qemu_proc_pathname, qargp, envp)); - } else { - close(fd); - /* Execve() as a host native binary. */ - ret = get_errno(execve(p, argp, envp)); - } + ret = get_errno(execve(p, argp, envp)); unlock_user(p, path_or_fd, 0); } diff --git a/bsd-user/main.c b/bsd-user/main.c index dcad266..82e94a0 100644 --- a/bsd-user/main.c +++ b/bsd-user/main.c @@ -90,7 +90,6 @@ unsigned long reserved_va; const char *interp_prefix = CONFIG_QEMU_INTERP_PREFIX; const char *qemu_uname_release; -char qemu_proc_pathname[PATH_MAX]; /* full path to exeutable */ unsigned long target_maxtsiz = TARGET_MAXTSIZ; /* max text size */ unsigned long target_dfldsiz = TARGET_DFLDSIZ; /* initial data size limit */ @@ -247,22 +246,6 @@ adjust_ssize(void) setrlimit(RLIMIT_STACK, &rl); } -static void save_proc_pathname(char *argv0) -{ - int mib[4]; - size_t len; - - mib[0] = CTL_KERN; - mib[1] = KERN_PROC; - mib[2] = KERN_PROC_PATHNAME; - mib[3] = -1; - - len = sizeof(qemu_proc_pathname); - if (sysctl(mib, 4, qemu_proc_pathname, &len, NULL, 0)) { - perror("sysctl"); - } -} - int main(int argc, char **argv) { const char *filename; @@ -292,7 +275,6 @@ int main(int argc, char **argv) usage(); } - save_proc_pathname(argv[0]); error_init(argv[0]); module_call_init(MODULE_INIT_TRACE); -- cgit v1.1