diff options
Diffstat (limited to 'elf')
| -rw-r--r-- | elf/pldd.c | 115 |
1 files changed, 90 insertions, 25 deletions
diff --git a/elf/pldd.c b/elf/pldd.c index 9fac19ebe4..ef3621c624 100644 --- a/elf/pldd.c +++ b/elf/pldd.c @@ -20,6 +20,8 @@ #include <alloca.h> #include <argp.h> +#include <assert.h> +#include <dirent.h> #include <elf.h> #include <errno.h> #include <error.h> @@ -83,7 +85,7 @@ static int memfd; static char *exe; /* Local functions. */ -static int get_process_info (pid_t pid); +static int get_process_info (int dfd, long int pid); int @@ -101,33 +103,96 @@ main (int argc, char *argv[]) return 1; } + assert (sizeof (pid_t) == sizeof (int) + || sizeof (pid_t) == sizeof (long int)); char *endp; errno = 0; - pid_t pid = strtoul (argv[remaining], &endp, 10); - if ((pid == ULONG_MAX && errno == ERANGE) || *endp != '\0') + long int pid = strtol (argv[remaining], &endp, 10); + if (pid < 0 || (pid == ULONG_MAX && errno == ERANGE) || *endp != '\0' + || (sizeof (pid_t) < sizeof (pid) && pid > INT_MAX)) error (EXIT_FAILURE, 0, gettext ("invalid process ID '%s'"), argv[remaining]); /* Determine the program name. */ - char buf[11 + 3 * sizeof (pid)]; - snprintf (buf, sizeof (buf), "/proc/%lu/exe", (unsigned long int) pid); + char buf[7 + 3 * sizeof (pid)]; + snprintf (buf, sizeof (buf), "/proc/%lu", pid); + int dfd = open (buf, O_RDONLY | O_DIRECTORY); + if (dfd == -1) + error (EXIT_FAILURE, errno, gettext ("cannot open %s"), buf); + size_t exesize = 1024; +#ifdef PATH_MAX + exesize = PATH_MAX; +#endif exe = alloca (exesize); ssize_t nexe; - while ((nexe = readlink (buf, exe, exesize)) == exesize) + while ((nexe = readlinkat (dfd, "exe", exe, exesize)) == exesize) extend_alloca (exe, exesize, 2 * exesize); if (nexe == -1) exe = (char *) "<program name undetermined>"; else exe[nexe] = '\0'; - if (ptrace (PTRACE_ATTACH, pid, NULL, NULL) != 0) - error (EXIT_FAILURE, errno, gettext ("cannot attach to process %lu"), - (unsigned long int) pid); + /* Stop all threads since otherwise the list of loaded modules might + change while we are reading it. */ + struct thread_list + { + pid_t tid; + struct thread_list *next; + } *thread_list = NULL; + + int taskfd = openat (dfd, "task", O_RDONLY | O_DIRECTORY | O_CLOEXEC); + if (taskfd == 1) + error (EXIT_FAILURE, errno, gettext ("cannot open %s/task"), buf); + DIR *dir = fdopendir (taskfd); + if (dir == NULL) + error (EXIT_FAILURE, errno, gettext ("cannot prepare reading %s/task"), + buf); + + struct dirent64 *d; + while ((d = readdir64 (dir)) != NULL) + { + if (! isdigit (d->d_name[0])) + continue; + + errno = 0; + long int tid = strtol (d->d_name, &endp, 10); + if (tid < 0 || (tid == ULONG_MAX && errno == ERANGE) || *endp != '\0' + || (sizeof (pid_t) < sizeof (pid) && tid > INT_MAX)) + error (EXIT_FAILURE, 0, gettext ("invalid thread ID '%s'"), + d->d_name); + + if (ptrace (PTRACE_ATTACH, tid, NULL, NULL) != 0) + { + /* There might be a race between reading the directory and + threads terminating. Ignore errors attaching to unknown + threads unless this is the main thread. */ + if (errno == ESRCH && tid != pid) + continue; + + error (EXIT_FAILURE, errno, gettext ("cannot attach to process %lu"), + tid); + } + + struct thread_list *newp = alloca (sizeof (*newp)); + newp->tid = tid; + newp->next = thread_list; + thread_list = newp; + } + + closedir (dir); - int status = get_process_info (pid); + int status = get_process_info (dfd, pid); + + assert (thread_list != NULL); + do + { + ptrace (PTRACE_DETACH, thread_list->tid, NULL, NULL); + thread_list = thread_list->next; + } + while (thread_list != NULL); - ptrace (PTRACE_DETACH, pid, NULL, NULL); + close (dfd); return status; } @@ -167,22 +232,18 @@ warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\ static int -get_process_info (pid_t pid) +get_process_info (int dfd, long int pid) { - char buf[12 + 3 * sizeof (pid)]; - - snprintf (buf, sizeof (buf), "/proc/%lu/mem", (unsigned long int) pid); - memfd = open (buf, O_RDONLY); + memfd = openat (dfd, "mem", O_RDONLY); if (memfd == -1) goto no_info; - snprintf (buf, sizeof (buf), "/proc/%lu/exe", (unsigned long int) pid); - int fd = open (buf, O_RDONLY); + int fd = openat (dfd, "exe", O_RDONLY); if (fd == -1) { no_info: error (0, errno, gettext ("cannot get information about process %lu"), - (unsigned long int) pid); + pid); return EXIT_FAILURE; } @@ -198,13 +259,11 @@ get_process_info (pid_t pid) if (memcmp (uehdr.ehdr32.e_ident, ELFMAG, SELFMAG) != 0) { - error (0, 0, gettext ("process %lu is no ELF program"), - (unsigned long int) pid); + error (0, 0, gettext ("process %lu is no ELF program"), pid); return EXIT_FAILURE; } - snprintf (buf, sizeof (buf), "/proc/%lu/auxv", (unsigned long int) pid); - fd = open (buf, O_RDONLY); + fd = openat (dfd, "auxv", O_RDONLY); if (fd == -1) goto no_info; @@ -227,8 +286,14 @@ get_process_info (pid_t pid) close (fd); + int retval; if (uehdr.ehdr32.e_ident[EI_CLASS] == ELFCLASS32) - return find_maps32 (pid, &uehdr.ehdr32, auxv, auxv_size); + retval = find_maps32 (pid, &uehdr.ehdr32, auxv, auxv_size); else - return find_maps64 (pid, &uehdr.ehdr64, auxv, auxv_size); + retval = find_maps64 (pid, &uehdr.ehdr64, auxv, auxv_size); + + free (auxv); + close (memfd); + + return retval; } |