From: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Karim Taha <kariem.taha2.7@gmail.com>
---
bsd-user/freebsd/os-proc.c | 177 +++++++++++++++++++++++++++++++++++++
bsd-user/main.c | 2 +-
bsd-user/qemu.h | 1 +
3 files changed, 179 insertions(+), 1 deletion(-)
But see comment below.
diff --git a/bsd-user/freebsd/os-proc.c b/bsd-user/freebsd/os-proc.c
index cb35f29f10..12d78b7fc9 100644
--- a/bsd-user/freebsd/os-proc.c
+++ b/bsd-user/freebsd/os-proc.c
@@ -78,3 +78,180 @@ out:
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;
+ int argc, envc;
+ abi_ulong gp;
+ abi_ulong addr;
+ char **q;
+ int total_size = 0;
+ void *p;
+ abi_long ret;
+
+ argc = 0;
+ for (gp = guest_argp; gp; gp += sizeof(abi_ulong)) {
+ if (get_user_ual(addr, gp)) {
+ return -TARGET_EFAULT;
+ }
+ if (!addr) {
+ break;
+ }
+ argc++;
+ }
+ envc = 0;
+ for (gp = guest_envp; gp; gp += sizeof(abi_ulong)) {
+ if (get_user_ual(addr, gp)) {
+ return -TARGET_EFAULT;
+ }
+ if (!addr) {
+ break;
+ }
+ envc++;
+ }
+
+ qarg0 = argp = g_new0(char *, argc + 9);
+ /* save the first agrument 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)) {
+ ret = -TARGET_EFAULT;
+ goto execve_end;
+ }
+ if (!addr) {
+ break;
+ }
+ *q = lock_user_string(addr);
+ if (*q == NULL) {
+ ret = -TARGET_EFAULT;
+ goto execve_end;
+ }
+ 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)) {
+ ret = -TARGET_EFAULT;
+ goto execve_end;
+ }
+ if (!addr) {
+ break;
+ }
+ *q = lock_user_string(addr);
+ if (*q == NULL) {
+ ret = -TARGET_EFAULT;
+ goto execve_end;
+ }
+ total_size += strlen(*q) + 1;
+ }
+ *q = NULL;
+
+ /*
+ * This case will not be caught by the host's execve() if its
+ * page size is bigger than the target's.
+ */
+ if (total_size > MAX_ARG_PAGES * TARGET_PAGE_SIZE) {
+ ret = -TARGET_E2BIG;
+ goto execve_end;
+ }
+
+ 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.
+ */
So we do this fd dance so we can make things like 'qemu-arm-static /armv7/bin/sh' work.
Doug Rabson has some changes that means we can ditch this, I think, since the
kernel will just track it and it will default to 'what is doing the current process'
rather than the system default for the same binfmt entry.
+ 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
And we do this inheritance so we can pass in a non-standard library path,
maybe for testing, and have the above example also work.
Warner
+ 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));
+ }
+ } 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));
+ }
+ unlock_user(p, path_or_fd, 0);
+ }
It might be nice to unify these two if statements, but I'm thinking
we don't want to do it now since Doug's work will obsolete it if I
understand it correctly.
Warner
+execve_end:
+ for (gp = guest_argp, q = argp; *q; gp += sizeof(abi_ulong), q++) {
+ if (get_user_ual(addr, gp) || !addr) {
+ break;
+ }
+ unlock_user(*q, addr, 0);
+ }
+
+ for (gp = guest_envp, q = envp; *q; gp += sizeof(abi_ulong), q++) {
+ if (get_user_ual(addr, gp) || !addr) {
+ break;
+ }
+ unlock_user(*q, addr, 0);
+ }
+
+ g_free(qarg0);
+ g_free(envp);
+
+ return ret;
+}
+
diff --git a/bsd-user/main.c b/bsd-user/main.c
index f913cb55a7..a12b4be80f 100644
--- a/bsd-user/main.c
+++ b/bsd-user/main.c
@@ -88,7 +88,7 @@ unsigned long reserved_va = MAX_RESERVED_VA;
unsigned long reserved_va;
#endif
-static const char *interp_prefix = CONFIG_QEMU_INTERP_PREFIX;
+const char *interp_prefix = CONFIG_QEMU_INTERP_PREFIX;
const char *qemu_uname_release;
char qemu_proc_pathname[PATH_MAX]; /* full path to exeutable */
diff --git a/bsd-user/qemu.h b/bsd-user/qemu.h
index 2cf96d9a15..1ed6024b5d 100644
--- a/bsd-user/qemu.h
+++ b/bsd-user/qemu.h
@@ -111,6 +111,7 @@ typedef struct TaskState {
} __attribute__((aligned(16))) TaskState;
void stop_all_tasks(void);
+extern const char *interp_prefix;
extern const char *qemu_uname_release;
/*
--
2.42.0