Message ID | 20210512185312.938871-1-adhemerval.zanella@linaro.org |
---|---|
State | New |
Headers | show |
Series | [v2] nptl: Fix tst-pthread-gdb-attach for ptrace_scope equal 1 | expand |
On 12/05/2021 15:53, Adhemerval Zanella wrote: > @@ -141,7 +146,7 @@ subprocess_thread (void *closure) > second thread, waiting for its value to change to 2, and checks > that the main thread also changed its value to 1. */ > static void > -in_subprocess (void) > +in_subprocess (void *arg) This change is not necessary, I will remove it.
On 12/05/2021 15:53, Adhemerval Zanella wrote: > This is similar to the fix for elf/tst-pldd (2f9046fb059e94fe25): > it checks ptrace_scope value (values higher than 2 are too restrictive > to allow the test to run) and it rearranges the spawned processes > to make the target process the gdb child. > > Checked on x86_64-linux-gnu with ptrace_scope set to 1. Florian, are this patch ok? The nptl/tst-pthread-gdb-attach failures are annoying and make is hard to check for regressions. > --- > nptl/tst-pthread-gdb-attach.c | 59 +++++++++++++++++++++++++---------- > 1 file changed, 42 insertions(+), 17 deletions(-) > > diff --git a/nptl/tst-pthread-gdb-attach.c b/nptl/tst-pthread-gdb-attach.c > index 901a120034..3c6eed07f6 100644 > --- a/nptl/tst-pthread-gdb-attach.c > +++ b/nptl/tst-pthread-gdb-attach.c > @@ -23,16 +23,21 @@ > #include <elf.h> > #include <errno.h> > #include <fcntl.h> > +#include <signal.h> > #include <stdbool.h> > #include <stdlib.h> > #include <string.h> > +#include <support/capture_subprocess.h> > #include <support/check.h> > +#include <support/xptrace.h> > +#include <support/subprocess.h> > #include <support/support.h> > #include <support/temp_file.h> > #include <support/test-driver.h> > #include <support/xstdio.h> > #include <support/xthread.h> > #include <support/xunistd.h> > +#include <sys/mman.h> > #include <unistd.h> > > /* Starts out as zero, changed to 1 or 2 by the debugger, depending on > @@ -141,7 +146,7 @@ subprocess_thread (void *closure) > second thread, waiting for its value to change to 2, and checks > that the main thread also changed its value to 1. */ > static void > -in_subprocess (void) > +in_subprocess (void *arg) > { > pthread_t thr = xpthread_create (NULL, subprocess_thread, NULL); > TEST_VERIFY (xpthread_join (thr) == NULL); > @@ -149,6 +154,26 @@ in_subprocess (void) > _exit (0); > } > > +static void > +gdb_process (const char *gdb_path, const char *gdbscript, pid_t *tested_pid) > +{ > + /* Create a copy of current test to check with gdb. As the > + target_process is a child of this gdb_process, gdb is also able > + to attach to target_process if YAMA is configured to 1 = > + "restricted ptrace". */ > + struct support_subprocess target = support_subprocess (in_subprocess, NULL); > + > + write_gdbscript (gdbscript, target.pid); > + *tested_pid = target.pid; > + > + xdup2 (STDOUT_FILENO, STDERR_FILENO); > + execl (gdb_path, "gdb", "-nx", "-batch", "-x", gdbscript, NULL); > + if (errno == ENOENT) > + _exit (EXIT_UNSUPPORTED); > + else > + _exit (1); > +} > + > static int > do_test (void) > { > @@ -179,25 +204,25 @@ do_test (void) > free (threaddb_path); > } > > - pid_t tested_pid = xfork (); > - if (tested_pid == 0) > - in_subprocess (); > - char *tested_pid_string = xasprintf ("%d", tested_pid); > + /* Check if our subprocess can be debugged with ptrace. */ > + { > + int ptrace_scope = support_ptrace_scope (); > + if (ptrace_scope >= 2) > + FAIL_UNSUPPORTED ("/proc/sys/kernel/yama/ptrace_scope >= 2"); > + } > > char *gdbscript; > xclose (create_temp_file ("tst-pthread-gdb-attach-", &gdbscript)); > - write_gdbscript (gdbscript, tested_pid); > + > + /* Run 'gdb' on test subprocess which will be created in gdb_process. > + The pid of the subprocess will be written to 'tested_pid'. */ > + pid_t *tested_pid = (pid_t *) xmmap (NULL, sizeof (pid_t), > + PROT_READ | PROT_WRITE, > + MAP_SHARED | MAP_ANONYMOUS, -1); > > pid_t gdb_pid = xfork (); > if (gdb_pid == 0) > - { > - xdup2 (STDOUT_FILENO, STDERR_FILENO); > - execl (gdb_path, "gdb", "-nx", "-batch", "-x", gdbscript, NULL); > - if (errno == ENOENT) > - _exit (EXIT_UNSUPPORTED); > - else > - _exit (1); > - } > + gdb_process (gdb_path, gdbscript, tested_pid); > > int status; > TEST_COMPARE (xwaitpid (gdb_pid, &status, 0), gdb_pid); > @@ -205,10 +230,10 @@ do_test (void) > /* gdb is not installed. */ > return EXIT_UNSUPPORTED; > TEST_COMPARE (status, 0); > - TEST_COMPARE (xwaitpid (tested_pid, &status, 0), tested_pid); > - TEST_COMPARE (status, 0); > > - free (tested_pid_string); > + kill (*tested_pid, SIGKILL); > + > + xmunmap (tested_pid, sizeof (pid_t)); > free (gdbscript); > free (gdb_path); > return 0; >
* Adhemerval Zanella via Libc-alpha: > + /* Run 'gdb' on test subprocess which will be created in gdb_process. > + The pid of the subprocess will be written to 'tested_pid'. */ > + pid_t *tested_pid = (pid_t *) xmmap (NULL, sizeof (pid_t), > + PROT_READ | PROT_WRITE, > + MAP_SHARED | MAP_ANONYMOUS, -1); We have support_shared_allocate for this. Rest looks okay. Thanks, Florian
diff --git a/nptl/tst-pthread-gdb-attach.c b/nptl/tst-pthread-gdb-attach.c index 901a120034..3c6eed07f6 100644 --- a/nptl/tst-pthread-gdb-attach.c +++ b/nptl/tst-pthread-gdb-attach.c @@ -23,16 +23,21 @@ #include <elf.h> #include <errno.h> #include <fcntl.h> +#include <signal.h> #include <stdbool.h> #include <stdlib.h> #include <string.h> +#include <support/capture_subprocess.h> #include <support/check.h> +#include <support/xptrace.h> +#include <support/subprocess.h> #include <support/support.h> #include <support/temp_file.h> #include <support/test-driver.h> #include <support/xstdio.h> #include <support/xthread.h> #include <support/xunistd.h> +#include <sys/mman.h> #include <unistd.h> /* Starts out as zero, changed to 1 or 2 by the debugger, depending on @@ -141,7 +146,7 @@ subprocess_thread (void *closure) second thread, waiting for its value to change to 2, and checks that the main thread also changed its value to 1. */ static void -in_subprocess (void) +in_subprocess (void *arg) { pthread_t thr = xpthread_create (NULL, subprocess_thread, NULL); TEST_VERIFY (xpthread_join (thr) == NULL); @@ -149,6 +154,26 @@ in_subprocess (void) _exit (0); } +static void +gdb_process (const char *gdb_path, const char *gdbscript, pid_t *tested_pid) +{ + /* Create a copy of current test to check with gdb. As the + target_process is a child of this gdb_process, gdb is also able + to attach to target_process if YAMA is configured to 1 = + "restricted ptrace". */ + struct support_subprocess target = support_subprocess (in_subprocess, NULL); + + write_gdbscript (gdbscript, target.pid); + *tested_pid = target.pid; + + xdup2 (STDOUT_FILENO, STDERR_FILENO); + execl (gdb_path, "gdb", "-nx", "-batch", "-x", gdbscript, NULL); + if (errno == ENOENT) + _exit (EXIT_UNSUPPORTED); + else + _exit (1); +} + static int do_test (void) { @@ -179,25 +204,25 @@ do_test (void) free (threaddb_path); } - pid_t tested_pid = xfork (); - if (tested_pid == 0) - in_subprocess (); - char *tested_pid_string = xasprintf ("%d", tested_pid); + /* Check if our subprocess can be debugged with ptrace. */ + { + int ptrace_scope = support_ptrace_scope (); + if (ptrace_scope >= 2) + FAIL_UNSUPPORTED ("/proc/sys/kernel/yama/ptrace_scope >= 2"); + } char *gdbscript; xclose (create_temp_file ("tst-pthread-gdb-attach-", &gdbscript)); - write_gdbscript (gdbscript, tested_pid); + + /* Run 'gdb' on test subprocess which will be created in gdb_process. + The pid of the subprocess will be written to 'tested_pid'. */ + pid_t *tested_pid = (pid_t *) xmmap (NULL, sizeof (pid_t), + PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_ANONYMOUS, -1); pid_t gdb_pid = xfork (); if (gdb_pid == 0) - { - xdup2 (STDOUT_FILENO, STDERR_FILENO); - execl (gdb_path, "gdb", "-nx", "-batch", "-x", gdbscript, NULL); - if (errno == ENOENT) - _exit (EXIT_UNSUPPORTED); - else - _exit (1); - } + gdb_process (gdb_path, gdbscript, tested_pid); int status; TEST_COMPARE (xwaitpid (gdb_pid, &status, 0), gdb_pid); @@ -205,10 +230,10 @@ do_test (void) /* gdb is not installed. */ return EXIT_UNSUPPORTED; TEST_COMPARE (status, 0); - TEST_COMPARE (xwaitpid (tested_pid, &status, 0), tested_pid); - TEST_COMPARE (status, 0); - free (tested_pid_string); + kill (*tested_pid, SIGKILL); + + xmunmap (tested_pid, sizeof (pid_t)); free (gdbscript); free (gdb_path); return 0;