Date: Tue, 24 Oct 2017 12:56:09 +0000 (UTC) From: Edward Tomasz Napierala <trasz@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r324953 - head/libexec/rtld-elf Message-ID: <201710241256.v9OCu9ie052150@repo.freebsd.org>
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Author: trasz Date: Tue Oct 24 12:56:08 2017 New Revision: 324953 URL: https://svnweb.freebsd.org/changeset/base/324953 Log: Remove unneeded calls to access(2) from rtld(1); just call open(2) instead. The result looks like this: --- przed 2017-10-21 23:19:21.445034000 +0100 +++ po 2017-10-21 23:18:50.031865000 +0100 @@ -11,7 +11,6 @@ mmap(0x0,102,PROT_READ,MAP_PRIVATE,3,0x0) = 343665418 close(3) = 0 (0x0) open("/usr/local/etc/libmap.d",O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC,0165) ERR#2 'No such file or directory' munmap(0x80067d000,102) = 0 (0x0) -access("/usr/local/lib/libintl.so.8",F_OK) = 0 (0x0) openat(AT_FDCWD,"/usr/local/lib/libintl.so.8",O_RDONLY|O_CLOEXEC|O_VERIFY,00) = 3 (0x3) fstat(3,{ mode=-rw-r--r-- ,inode=642560,size=55188,blksize=32768 }) = 0 (0x0) mmap(0x0,4096,PROT_READ,MAP_PRIVATE|MAP_PREFAULT_READ,3,0x0) = 34366541824 (0x80067d000) @@ -20,14 +19,13 @@ mmap(0x800877000,40960,PROT_READ|PROT_EXEC,MAP_PRIVATE mmap(0x800a81000,4096,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_FIXED|MAP_PREFAULT_READ,3,0xa000) = 34370752512 (0x800a81000) munmap(0x80067d000,4096) = 0 (0x0) close(3) = 0 (0x0) -access("/usr/local/lib/libc.so.7",F_OK) ERR#2 'No such file or directory' +openat(AT_FDCWD,"/usr/local/lib/libc.so.7",O_RDONLY|O_CLOEXEC|O_VERIFY,00) ERR#2 'No such file or directory' openat(AT_FDCWD,"/var/run/ld-elf.so.hints",O_RDONLY|O_CLOEXEC,00) = 3 (0x3) read(3,"Ehnt\^A\0\0\0\M^@\0\0\0\M-2\0\0"...,128) = 128 (0x80) fstat(3,{ mode=-r--r--r-- ,inode=970684,size=306,blksize=32768 }) = 0 (0x0) lseek(3,0x80,SEEK_SET) = 128 (0x80) read(3,"/lib:/usr/lib:/usr/lib/compat:/u"...,178) = 178 (0xb2) close(3) = 0 (0x0) -access("/lib/libc.so.7",F_OK) = 0 (0x0) openat(AT_FDCWD,"/lib/libc.so.7",O_RDONLY|O_CLOEXEC|O_VERIFY,00) = 3 (0x3) fstat(3,{ mode=-r--r--r-- ,inode=1605239,size=1910320,blksize=32768 }) = 0 (0x0) mmap(0x0,4096,PROT_READ,MAP_PRIVATE|MAP_PREFAULT_READ,3,0x0) = 34366541824 (0x80067d000) Reviewed by: kib MFC after: 2 weeks Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D12766 Modified: head/libexec/rtld-elf/rtld.c Modified: head/libexec/rtld-elf/rtld.c ============================================================================== --- head/libexec/rtld-elf/rtld.c Tue Oct 24 12:04:07 2017 (r324952) +++ head/libexec/rtld-elf/rtld.c Tue Oct 24 12:56:08 2017 (r324953) @@ -138,7 +138,7 @@ static int rtld_dirname(const char *, char *); static int rtld_dirname_abs(const char *, char *); static void *rtld_dlopen(const char *name, int fd, int mode); static void rtld_exit(void); -static char *search_library_path(const char *, const char *); +static char *search_library_path(const char *, const char *, int *); static char *search_library_pathfds(const char *, const char *, int *); static const void **get_program_var_addr(const char *, RtldLockState *); static void set_program_var(const char *, const void *); @@ -1620,52 +1620,52 @@ find_library(const char *xname, const Obj_Entry *refob * nodeflib. */ if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { - pathname = search_library_path(name, ld_library_path); + pathname = search_library_path(name, ld_library_path, fdp); if (pathname != NULL) return (pathname); if (refobj != NULL) { - pathname = search_library_path(name, refobj->rpath); + pathname = search_library_path(name, refobj->rpath, fdp); if (pathname != NULL) return (pathname); } pathname = search_library_pathfds(name, ld_library_dirs, fdp); if (pathname != NULL) return (pathname); - pathname = search_library_path(name, gethints(false)); + pathname = search_library_path(name, gethints(false), fdp); if (pathname != NULL) return (pathname); - pathname = search_library_path(name, ld_standard_library_path); + pathname = search_library_path(name, ld_standard_library_path, fdp); if (pathname != NULL) return (pathname); } else { nodeflib = objgiven ? refobj->z_nodeflib : false; if (objgiven) { - pathname = search_library_path(name, refobj->rpath); + pathname = search_library_path(name, refobj->rpath, fdp); if (pathname != NULL) return (pathname); } if (objgiven && refobj->runpath == NULL && refobj != obj_main) { - pathname = search_library_path(name, obj_main->rpath); + pathname = search_library_path(name, obj_main->rpath, fdp); if (pathname != NULL) return (pathname); } - pathname = search_library_path(name, ld_library_path); + pathname = search_library_path(name, ld_library_path, fdp); if (pathname != NULL) return (pathname); if (objgiven) { - pathname = search_library_path(name, refobj->runpath); + pathname = search_library_path(name, refobj->runpath, fdp); if (pathname != NULL) return (pathname); } pathname = search_library_pathfds(name, ld_library_dirs, fdp); if (pathname != NULL) return (pathname); - pathname = search_library_path(name, gethints(nodeflib)); + pathname = search_library_path(name, gethints(nodeflib), fdp); if (pathname != NULL) return (pathname); if (objgiven && !nodeflib) { pathname = search_library_path(name, - ld_standard_library_path); + ld_standard_library_path, fdp); if (pathname != NULL) return (pathname); } @@ -3022,12 +3022,14 @@ struct try_library_args { size_t namelen; char *buffer; size_t buflen; + int fd; }; static void * try_library_path(const char *dir, size_t dirlen, void *param) { struct try_library_args *arg; + int fd; arg = param; if (*dir == '/' || trust) { @@ -3042,17 +3044,23 @@ try_library_path(const char *dir, size_t dirlen, void strcpy(pathname + dirlen + 1, arg->name); dbg(" Trying \"%s\"", pathname); - if (access(pathname, F_OK) == 0) { /* We found it */ + fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); + if (fd >= 0) { + dbg(" Opened \"%s\", fd %d", pathname, fd); pathname = xmalloc(dirlen + 1 + arg->namelen + 1); strcpy(pathname, arg->buffer); + arg->fd = fd; return (pathname); + } else { + dbg(" Failed to open \"%s\": %s", + pathname, rtld_strerror(errno)); } } return (NULL); } static char * -search_library_path(const char *name, const char *path) +search_library_path(const char *name, const char *path, int *fdp) { char *p; struct try_library_args arg; @@ -3064,8 +3072,10 @@ search_library_path(const char *name, const char *path arg.namelen = strlen(name); arg.buffer = xmalloc(PATH_MAX); arg.buflen = PATH_MAX; + arg.fd = -1; p = path_enumerate(path, try_library_path, &arg); + *fdp = arg.fd; free(arg.buffer);
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