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author | Paul Eggert <eggert@cs.ucla.edu> | 2016-01-24 14:50:47 -0800 |
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committer | Paul Eggert <eggert@cs.ucla.edu> | 2016-01-24 14:51:22 -0800 |
commit | 1698036a43d9e2c55ead6216ea7156df8615da47 (patch) | |
tree | 60bb61c907536ebc38c6b301fd754028b8a9b542 /lib/openat-proc.c | |
parent | fbce4757a874cc43806eb41b8637538b101c3c69 (diff) | |
download | emacs-1698036a43d9e2c55ead6216ea7156df8615da47.tar.gz emacs-1698036a43d9e2c55ead6216ea7156df8615da47.tar.bz2 emacs-1698036a43d9e2c55ead6216ea7156df8615da47.zip |
Merge from gnulib
This incorporates:
2016-01-24 openat_proc_name: fix last '/' overwritten on OS/2 kLIBC
2016-01-24 closedir, dirfd, opendir: port to OpenSolaris 5.10
2016-01-15 detect utimes() correctly on OS/2 kLIBC
2016-01-15 openat_proc_name: port to OS/2 kLIBC
2016-01-14 stdint: check _INTPTR_T_DECLARED for intptr_t etc.
2016-01-14 opendir, closedir, dirfd, fdopendir: port to OS/2 kLIBC
2016-01-14 dup, dup2, fcntl: support a directory fd on OS/2 kLIBC
2016-01-14 binary-io: don't put fd in binary mode if a console on EMX
2016-01-14 sig2str: list all signals on FreeBSD >= 7
2016-01-13 acl-permissions: port to USE_ACL==0 platforms
2016-01-12 mktime: rename macro to avoid glibc clash
2016-01-12 Port "$@" to OpenIndiana ksh93
2016-01-12 Port Universal Time settings to strict POSIX
* build-aux/gitlog-to-changelog, build-aux/update-copyright:
* doc/misc/texinfo.tex, lib/acl-internal.c, lib/acl-internal.h:
* lib/binary-io.h, lib/dirent.in.h, lib/dirfd.c, lib/dup2.c:
* lib/fcntl.c, lib/fdopendir.c, lib/mktime.c, lib/openat-proc.c:
* lib/sig2str.h, lib/stdint.in.h, m4/dirfd.m4, m4/dup2.m4:
* m4/fcntl.m4, m4/utimes.m4:
Copy from gnulib.
* m4/gnulib-comp.m4: Regenerate.
Diffstat (limited to 'lib/openat-proc.c')
-rw-r--r-- | lib/openat-proc.c | 144 |
1 files changed, 88 insertions, 56 deletions
diff --git a/lib/openat-proc.c b/lib/openat-proc.c index 15a8c799c80..1712340a002 100644 --- a/lib/openat-proc.c +++ b/lib/openat-proc.c @@ -30,24 +30,21 @@ #include <string.h> #include <unistd.h> -#include "intprops.h" - -#define PROC_SELF_FD_FORMAT "/proc/self/fd/%d/%s" - -#define PROC_SELF_FD_NAME_SIZE_BOUND(len) \ - (sizeof PROC_SELF_FD_FORMAT - sizeof "%d%s" \ - + INT_STRLEN_BOUND (int) + (len) + 1) +#ifdef __KLIBC__ +# include <InnoTekLIBC/backend.h> +#endif +#include "intprops.h" -/* Set BUF to the expansion of PROC_SELF_FD_FORMAT, using FD and FILE - respectively for %d and %s. If successful, return BUF if the - result fits in BUF, dynamically allocated memory otherwise. But - return NULL if /proc is not reliable, either because the operating - system support is lacking or because memory is low. */ +/* Set BUF to the name of the subfile of the directory identified by + FD, where the subfile is named FILE. If successful, return BUF if + the result fits in BUF, dynamically allocated memory otherwise. + Return NULL (setting errno) on error. */ char * openat_proc_name (char buf[OPENAT_BUFFER_SIZE], int fd, char const *file) { - static int proc_status = 0; + char *result = buf; + int dirlen; /* Make sure the caller gets ENOENT when appropriate. */ if (!*file) @@ -56,47 +53,82 @@ openat_proc_name (char buf[OPENAT_BUFFER_SIZE], int fd, char const *file) return buf; } - if (! proc_status) - { - /* Set PROC_STATUS to a positive value if /proc/self/fd is - reliable, and a negative value otherwise. Solaris 10 - /proc/self/fd mishandles "..", and any file name might expand - to ".." after symbolic link expansion, so avoid /proc/self/fd - if it mishandles "..". Solaris 10 has openat, but this - problem is exhibited on code that built on Solaris 8 and - running on Solaris 10. */ - - int proc_self_fd = open ("/proc/self/fd", - O_SEARCH | O_DIRECTORY | O_NOCTTY | O_NONBLOCK); - if (proc_self_fd < 0) - proc_status = -1; - else - { - /* Detect whether /proc/self/fd/%i/../fd exists, where %i is the - number of a file descriptor open on /proc/self/fd. On Linux, - that name resolves to /proc/self/fd, which was opened above. - However, on Solaris, it may resolve to /proc/self/fd/fd, which - cannot exist, since all names in /proc/self/fd are numeric. */ - char dotdot_buf[PROC_SELF_FD_NAME_SIZE_BOUND (sizeof "../fd" - 1)]; - sprintf (dotdot_buf, PROC_SELF_FD_FORMAT, proc_self_fd, "../fd"); - proc_status = access (dotdot_buf, F_OK) ? -1 : 1; - close (proc_self_fd); - } - } - - if (proc_status < 0) - return NULL; - else - { - size_t bufsize = PROC_SELF_FD_NAME_SIZE_BOUND (strlen (file)); - char *result = buf; - if (OPENAT_BUFFER_SIZE < bufsize) - { - result = malloc (bufsize); - if (! result) - return NULL; - } - sprintf (result, PROC_SELF_FD_FORMAT, fd, file); - return result; - } +#ifndef __KLIBC__ +# define PROC_SELF_FD_FORMAT "/proc/self/fd/%d/" + { + enum { + PROC_SELF_FD_DIR_SIZE_BOUND + = (sizeof PROC_SELF_FD_FORMAT - (sizeof "%d" - 1) + + INT_STRLEN_BOUND (int)) + }; + + static int proc_status = 0; + if (! proc_status) + { + /* Set PROC_STATUS to a positive value if /proc/self/fd is + reliable, and a negative value otherwise. Solaris 10 + /proc/self/fd mishandles "..", and any file name might expand + to ".." after symbolic link expansion, so avoid /proc/self/fd + if it mishandles "..". Solaris 10 has openat, but this + problem is exhibited on code that built on Solaris 8 and + running on Solaris 10. */ + + int proc_self_fd = open ("/proc/self/fd", + O_SEARCH | O_DIRECTORY | O_NOCTTY | O_NONBLOCK); + if (proc_self_fd < 0) + proc_status = -1; + else + { + /* Detect whether /proc/self/fd/%i/../fd exists, where %i is the + number of a file descriptor open on /proc/self/fd. On Linux, + that name resolves to /proc/self/fd, which was opened above. + However, on Solaris, it may resolve to /proc/self/fd/fd, which + cannot exist, since all names in /proc/self/fd are numeric. */ + char dotdot_buf[PROC_SELF_FD_DIR_SIZE_BOUND + sizeof "../fd" - 1]; + sprintf (dotdot_buf, PROC_SELF_FD_FORMAT "../fd", proc_self_fd); + proc_status = access (dotdot_buf, F_OK) ? -1 : 1; + close (proc_self_fd); + } + } + + if (proc_status < 0) + return NULL; + else + { + size_t bufsize = PROC_SELF_FD_DIR_SIZE_BOUND + strlen (file); + if (OPENAT_BUFFER_SIZE < bufsize) + { + result = malloc (bufsize); + if (! result) + return NULL; + } + + dirlen = sprintf (result, PROC_SELF_FD_FORMAT, fd); + } + } +#else + /* OS/2 kLIBC provides a function to retrieve a path from a fd. */ + { + char dir[_MAX_PATH]; + size_t bufsize; + + if (__libc_Back_ioFHToPath (fd, dir, sizeof dir)) + return NULL; + + dirlen = strlen (dir); + bufsize = dirlen + 1 + strlen (file) + 1; /* 1 for '/', 1 for null */ + if (OPENAT_BUFFER_SIZE < bufsize) + { + result = malloc (bufsize); + if (! result) + return NULL; + } + + strcpy (result, dir); + result[dirlen++] = '/'; + } +#endif + + strcpy (result + dirlen, file); + return result; } |