| Message ID | 20230212111044.610942-2-bugaevc@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | Towards glibc on x86_64-gnu | expand |
Applied, thanks! Sergey Bugaev via Libc-alpha, le dim. 12 févr. 2023 14:10:32 +0300, a ecrit: > Make the code flow more linear using early returns where possible. This > makes it so much easier to reason about what runs on error / successful > code paths. > > Signed-off-by: Sergey Bugaev <bugaevc@gmail.com> > --- > sysdeps/mach/hurd/readlinkat.c | 55 ++++++++++++++++++++-------------- > 1 file changed, 32 insertions(+), 23 deletions(-) > > diff --git a/sysdeps/mach/hurd/readlinkat.c b/sysdeps/mach/hurd/readlinkat.c > index 1efb09ca..dabdbb37 100644 > --- a/sysdeps/mach/hurd/readlinkat.c > +++ b/sysdeps/mach/hurd/readlinkat.c > @@ -31,38 +31,47 @@ __readlinkat (int fd, const char *file_name, char *buf, size_t len) > error_t err; > file_t file_stat; > struct stat64 st; > + enum retry_type doretry; > + char retryname[1024]; > + file_t file; > + char *rbuf = buf; > > file_stat = __file_name_lookup_at (fd, 0, file_name, O_NOLINK, 0); > if (file_stat == MACH_PORT_NULL) > return -1; > > err = __io_stat (file_stat, &st); > - if (! err) > - if (S_ISLNK (st.st_mode)) > - { > - enum retry_type doretry; > - char retryname[1024]; > - file_t file; > - char *rbuf = buf; > + if (err) > + goto out; > + if (!S_ISLNK (st.st_mode)) > + { > + err = EINVAL; > + goto out; > + } > > - err = __dir_lookup (file_stat, "", O_READ | O_NOLINK, 0, &doretry, retryname, &file); > - if (! err && (doretry != FS_RETRY_NORMAL || retryname[0] != '\0')) > - err = EGRATUITOUS; > - if (! err) > - { > - err = __io_read (file, &rbuf, &len, 0, len); > - if (!err && rbuf != buf) > - { > - memcpy (buf, rbuf, len); > - __vm_deallocate (__mach_task_self (), (vm_address_t)rbuf, len); > - } > + err = __dir_lookup (file_stat, "", O_READ | O_NOLINK, > + 0, &doretry, retryname, &file); > + if (err) > + goto out; > + if (doretry != FS_RETRY_NORMAL || retryname[0] != '\0') > + { > + err = EGRATUITOUS; > + goto out; > + } > + > + err = __io_read (file, &rbuf, &len, 0, len); > + __mach_port_deallocate (__mach_task_self (), file); > + if (err) > + goto out; > + > + if (rbuf != buf) > + { > + memcpy (buf, rbuf, len); > + __vm_deallocate (__mach_task_self (), (vm_address_t) rbuf, len); > + } > > - __mach_port_deallocate (__mach_task_self (), file); > - } > - } > - else > - err = EINVAL; > > + out: > __mach_port_deallocate (__mach_task_self (), file_stat); > > return err ? __hurd_fail (err) : len; > -- > 2.39.1 >
diff --git a/sysdeps/mach/hurd/readlinkat.c b/sysdeps/mach/hurd/readlinkat.c index 1efb09ca..dabdbb37 100644 --- a/sysdeps/mach/hurd/readlinkat.c +++ b/sysdeps/mach/hurd/readlinkat.c @@ -31,38 +31,47 @@ __readlinkat (int fd, const char *file_name, char *buf, size_t len) error_t err; file_t file_stat; struct stat64 st; + enum retry_type doretry; + char retryname[1024]; + file_t file; + char *rbuf = buf; file_stat = __file_name_lookup_at (fd, 0, file_name, O_NOLINK, 0); if (file_stat == MACH_PORT_NULL) return -1; err = __io_stat (file_stat, &st); - if (! err) - if (S_ISLNK (st.st_mode)) - { - enum retry_type doretry; - char retryname[1024]; - file_t file; - char *rbuf = buf; + if (err) + goto out; + if (!S_ISLNK (st.st_mode)) + { + err = EINVAL; + goto out; + } - err = __dir_lookup (file_stat, "", O_READ | O_NOLINK, 0, &doretry, retryname, &file); - if (! err && (doretry != FS_RETRY_NORMAL || retryname[0] != '\0')) - err = EGRATUITOUS; - if (! err) - { - err = __io_read (file, &rbuf, &len, 0, len); - if (!err && rbuf != buf) - { - memcpy (buf, rbuf, len); - __vm_deallocate (__mach_task_self (), (vm_address_t)rbuf, len); - } + err = __dir_lookup (file_stat, "", O_READ | O_NOLINK, + 0, &doretry, retryname, &file); + if (err) + goto out; + if (doretry != FS_RETRY_NORMAL || retryname[0] != '\0') + { + err = EGRATUITOUS; + goto out; + } + + err = __io_read (file, &rbuf, &len, 0, len); + __mach_port_deallocate (__mach_task_self (), file); + if (err) + goto out; + + if (rbuf != buf) + { + memcpy (buf, rbuf, len); + __vm_deallocate (__mach_task_self (), (vm_address_t) rbuf, len); + } - __mach_port_deallocate (__mach_task_self (), file); - } - } - else - err = EINVAL; + out: __mach_port_deallocate (__mach_task_self (), file_stat); return err ? __hurd_fail (err) : len;
Make the code flow more linear using early returns where possible. This makes it so much easier to reason about what runs on error / successful code paths. Signed-off-by: Sergey Bugaev <bugaevc@gmail.com> --- sysdeps/mach/hurd/readlinkat.c | 55 ++++++++++++++++++++-------------- 1 file changed, 32 insertions(+), 23 deletions(-)