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* Update copyright dates with scripts/update-copyrights.Joseph Myers2018-01-011-1/+1
| | | | | | | * All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
* linux ttyname{_r}: Make tty checks consistentLuke Shumaker2017-11-151-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the ttyname and ttyname_r routines on Linux, at several points it needs to check if a given TTY is the TTY we are looking for. It used to be that this check was (to see if `maybe` is `mytty`): __xstat64(_STAT_VER, maybe_filename, &maybe) == 0 #ifdef _STATBUF_ST_RDEV && S_ISCHR(maybe.st_mode) && maybe.st_rdev == mytty.st_rdev #else && maybe.st_ino == mytty.st_ino && maybe.st_dev == mytty.st_dev #endif This check appears in several places. Then, one of the changes made in commit 15e9a4f378c8607c2ae1aa465436af4321db0e23 was to change that check to: __xstat64(_STAT_VER, maybe_filename, &maybe) == 0 #ifdef _STATBUF_ST_RDEV && S_ISCHR(maybe.st_mode) && maybe.st_rdev == mytty.st_rdev #endif && maybe.st_ino == mytty.st_ino && maybe.st_dev == mytty.st_dev That is, it made the st_ino and st_dev parts of the check happen even if we have the st_rdev member. This is an important change, because the kernel allows multiple devpts filesystem instances to be created; a device file in one devpts instance may share the same st_rdev with a file in another devpts instance, but they aren't the same file. This check appears twice in each file (ttyname.c and ttyname_r.c), once (in ttyname and __ttyname_r) to check if a candidate file found by inspecting /proc is the desired TTY, and once (in getttyname and getttyname_r) to check if a candidate file found by searching /dev is the desired TTY. However, 15e9a4f only updated the checks for files found via /proc; but the concern about collisions between devpts instances is just as valid for files found via /dev. So, update all 4 occurrences the check to be consistent with the version of the check introduced in 15e9a4f. Make it easy to keep all 4 occurrences of the check consistent by pulling it in to a static inline function, is_mytty. Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
* linux ttyname: Change return type of is_pty from int to boolLuke Shumaker2017-11-151-1/+2
| | | | | | | is_pty returning a bool is fine since there's no possible outcome other than true or false, and bool is used throughout the codebase. Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
* linux ttyname: Update a reference to kernel docs for kernel 4.10Luke Shumaker2017-11-151-1/+2
| | | | | | | | | | Linux 4.10 moved many of the documentation files around. 4.10 came out between the time the patch adding the comment (commit 15e9a4f378c8607c2ae1aa465436af4321db0e23) was submitted and the time it was applied (in February, January, and March 2017; respectively). Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
* linux ttyname and ttyname_r: do not return wrong resultsChristian Brauner2017-03-191-0/+34
If a link (say /proc/self/fd/0) pointing to a device, say /dev/pts/2, in a parent mount namespace is passed to ttyname, and a /dev/pts/2 exists (in a different devpts) in the current namespace, then it returns /dev/pts/2. But /dev/pts/2 is NOT the current tty, it is a different file and device. Detect this case and return ENODEV. Userspace can choose to take this as a hint that the fd points to a tty device but to act on the fd rather than the link. Signed-off-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>