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-rw-r--r--ChangeLog5
-rw-r--r--elf/pldd.c115
2 files changed, 95 insertions, 25 deletions
diff --git a/ChangeLog b/ChangeLog
index 6dbab2e347..ffb2ad3261 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2011-08-17 Ulrich Drepper <drepper@gmail.com>
+
+ * elf/pldd.c (main): Attach to all threads in the process.
+ Rewrite /proc handling to use *at functions.
+
2011-08-16 Ulrich Drepper <drepper@gmail.com>
* elf/dl-open.c (_dl_show_scope): Take additional parameter which
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;
}