| Message ID | 20250328144717.108054-1-lufei@uniontech.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | unshare_test: set nr_open using soft limit | expand |
Hi all, > Set maximum file descriptor number limit by rlimit.rlim_max than > nr_open(hard limit). Hard limit may cause dup2 fail. It actually changes from failure: # ./unshare_test TAP version 13 1..1 # Starting 1 tests from 1 test cases. # RUN global.unshare_EMFILE ... # unshare_test.c:60:unshare_EMFILE:Expected dup2(2, nr_open + 64) (-1) >= 0 (0) # unshare_EMFILE: Test failed # FAIL global.unshare_EMFILE not ok 1 global.unshare_EMFILE # FAILED: 0 / 1 tests passed. # Totals: pass:0 fail:1 xfail:0 xpass:0 skip:0 error:0 to pass: TAP version 13 1..1 # Starting 1 tests from 1 test cases. # RUN global.unshare_EMFILE ... # OK global.unshare_EMFILE ok 1 global.unshare_EMFILE # PASSED: 1 / 1 tests passed. # Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0 > Signed-off-by: lufei <lufei@uniontech.com> > --- > tools/testing/selftests/core/unshare_test.c | 28 +++++++++++++-------- > 1 file changed, 18 insertions(+), 10 deletions(-) > diff --git a/tools/testing/selftests/core/unshare_test.c b/tools/testing/selftests/core/unshare_test.c > index 7fec9dfb1b0e..2c4e7104b0d9 100644 > --- a/tools/testing/selftests/core/unshare_test.c > +++ b/tools/testing/selftests/core/unshare_test.c > @@ -26,10 +26,11 @@ TEST(unshare_EMFILE) > .exit_signal = SIGCHLD, > }; > int fd; > - ssize_t n, n2; > - static char buf[512], buf2[512]; > + ssize_t n, n2, n3; > + static char buf[512], buf2[512], buf3[512]; > struct rlimit rlimit; > int nr_open; > + int rlimit_max; > fd = open("/proc/sys/fs/nr_open", O_RDWR); > ASSERT_GE(fd, 0); > @@ -42,22 +43,24 @@ TEST(unshare_EMFILE) > ASSERT_EQ(0, getrlimit(RLIMIT_NOFILE, &rlimit)); > - /* bump fs.nr_open */ > - n2 = sprintf(buf2, "%d\n", nr_open + 1024); > + rlimit_max = rlimit.rlim_max; > + > + /* bump rlimit.rlim_max */ > + n2 = sprintf(buf2, "%d\n", rlimit_max + 1024); > lseek(fd, 0, SEEK_SET); > write(fd, buf2, n2); > /* bump ulimit -n */ > - rlimit.rlim_cur = nr_open + 1024; > - rlimit.rlim_max = nr_open + 1024; > + rlimit.rlim_cur = rlimit_max + 1024; > + rlimit.rlim_max = rlimit_max + 1024; > EXPECT_EQ(0, setrlimit(RLIMIT_NOFILE, &rlimit)) { > lseek(fd, 0, SEEK_SET); > write(fd, buf, n); > exit(EXIT_FAILURE); > } > - /* get a descriptor past the old fs.nr_open */ > - EXPECT_GE(dup2(2, nr_open + 64), 0) { > + /* get a descriptor past the old rlimit.rlim_max */ > + EXPECT_GE(dup2(2, rlimit_max + 64), 0) { > lseek(fd, 0, SEEK_SET); > write(fd, buf, n); > exit(EXIT_FAILURE); > @@ -74,15 +77,20 @@ TEST(unshare_EMFILE) > if (pid == 0) { > int err; > - /* restore fs.nr_open */ > + n3 = sprintf(buf3, "%d\n", rlimit_max); > lseek(fd, 0, SEEK_SET); > - write(fd, buf, n); > + write(fd, buf3, n3); nit: do we really need buf3? Can't we reuse buf2? Or do I miss something obvious? Reviewed-by: Petr Vorel <pvorel@suse.cz> Kind regards, Petr > + > /* ... and now unshare(CLONE_FILES) must fail with EMFILE */ > err = unshare(CLONE_FILES); > EXPECT_EQ(err, -1) > exit(EXIT_FAILURE); > EXPECT_EQ(errno, EMFILE) > exit(EXIT_FAILURE); > + > + /* restore fs.nr_open */ > + lseek(fd, 0, SEEK_SET); > + write(fd, buf, n); > exit(EXIT_SUCCESS); > }
Hi Petr, Thanks very much for reply. On Mon, Mar 31, 2025 at 08:32:27PM +0200, Petr Vorel wrote: > Hi all, > > > Set maximum file descriptor number limit by rlimit.rlim_max than > > nr_open(hard limit). Hard limit may cause dup2 fail. > > It actually changes from failure: > > # ./unshare_test > TAP version 13 > 1..1 > # Starting 1 tests from 1 test cases. > # RUN global.unshare_EMFILE ... > # unshare_test.c:60:unshare_EMFILE:Expected dup2(2, nr_open + 64) (-1) >= 0 (0) > # unshare_EMFILE: Test failed > # FAIL global.unshare_EMFILE > not ok 1 global.unshare_EMFILE > # FAILED: 0 / 1 tests passed. > # Totals: pass:0 fail:1 xfail:0 xpass:0 skip:0 error:0 > > to pass: > > TAP version 13 > 1..1 > # Starting 1 tests from 1 test cases. > # RUN global.unshare_EMFILE ... > # OK global.unshare_EMFILE > ok 1 global.unshare_EMFILE > # PASSED: 1 / 1 tests passed. > # Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0 > > > Signed-off-by: lufei <lufei@uniontech.com> > > --- > > tools/testing/selftests/core/unshare_test.c | 28 +++++++++++++-------- > > 1 file changed, 18 insertions(+), 10 deletions(-) > > > diff --git a/tools/testing/selftests/core/unshare_test.c b/tools/testing/selftests/core/unshare_test.c > > index 7fec9dfb1b0e..2c4e7104b0d9 100644 > > --- a/tools/testing/selftests/core/unshare_test.c > > +++ b/tools/testing/selftests/core/unshare_test.c > > @@ -26,10 +26,11 @@ TEST(unshare_EMFILE) > > .exit_signal = SIGCHLD, > > }; > > int fd; > > - ssize_t n, n2; > > - static char buf[512], buf2[512]; > > + ssize_t n, n2, n3; > > + static char buf[512], buf2[512], buf3[512]; > > struct rlimit rlimit; > > int nr_open; > > + int rlimit_max; > > > fd = open("/proc/sys/fs/nr_open", O_RDWR); > > ASSERT_GE(fd, 0); > > @@ -42,22 +43,24 @@ TEST(unshare_EMFILE) > > > ASSERT_EQ(0, getrlimit(RLIMIT_NOFILE, &rlimit)); > > > - /* bump fs.nr_open */ > > - n2 = sprintf(buf2, "%d\n", nr_open + 1024); > > + rlimit_max = rlimit.rlim_max; > > + > > + /* bump rlimit.rlim_max */ > > + n2 = sprintf(buf2, "%d\n", rlimit_max + 1024); > > lseek(fd, 0, SEEK_SET); > > write(fd, buf2, n2); > > > /* bump ulimit -n */ > > - rlimit.rlim_cur = nr_open + 1024; > > - rlimit.rlim_max = nr_open + 1024; > > + rlimit.rlim_cur = rlimit_max + 1024; > > + rlimit.rlim_max = rlimit_max + 1024; > > EXPECT_EQ(0, setrlimit(RLIMIT_NOFILE, &rlimit)) { > > lseek(fd, 0, SEEK_SET); > > write(fd, buf, n); > > exit(EXIT_FAILURE); > > } > > > - /* get a descriptor past the old fs.nr_open */ > > - EXPECT_GE(dup2(2, nr_open + 64), 0) { > > + /* get a descriptor past the old rlimit.rlim_max */ > > + EXPECT_GE(dup2(2, rlimit_max + 64), 0) { > > lseek(fd, 0, SEEK_SET); > > write(fd, buf, n); > > exit(EXIT_FAILURE); > > @@ -74,15 +77,20 @@ TEST(unshare_EMFILE) > > if (pid == 0) { > > int err; > > > - /* restore fs.nr_open */ > > + n3 = sprintf(buf3, "%d\n", rlimit_max); > > lseek(fd, 0, SEEK_SET); > > - write(fd, buf, n); > > + write(fd, buf3, n3); > nit: do we really need buf3? Can't we reuse buf2? > Or do I miss something obvious? > Reuse buf2 is better. I'll make change. > Reviewed-by: Petr Vorel <pvorel@suse.cz> > > Kind regards, > Petr > > > + > > /* ... and now unshare(CLONE_FILES) must fail with EMFILE */ > > err = unshare(CLONE_FILES); > > EXPECT_EQ(err, -1) > > exit(EXIT_FAILURE); > > EXPECT_EQ(errno, EMFILE) > > exit(EXIT_FAILURE); > > + > > + /* restore fs.nr_open */ > > + lseek(fd, 0, SEEK_SET); > > + write(fd, buf, n); > > exit(EXIT_SUCCESS); > > } >
diff --git a/tools/testing/selftests/core/unshare_test.c b/tools/testing/selftests/core/unshare_test.c index 7fec9dfb1b0e..2c4e7104b0d9 100644 --- a/tools/testing/selftests/core/unshare_test.c +++ b/tools/testing/selftests/core/unshare_test.c @@ -26,10 +26,11 @@ TEST(unshare_EMFILE) .exit_signal = SIGCHLD, }; int fd; - ssize_t n, n2; - static char buf[512], buf2[512]; + ssize_t n, n2, n3; + static char buf[512], buf2[512], buf3[512]; struct rlimit rlimit; int nr_open; + int rlimit_max; fd = open("/proc/sys/fs/nr_open", O_RDWR); ASSERT_GE(fd, 0); @@ -42,22 +43,24 @@ TEST(unshare_EMFILE) ASSERT_EQ(0, getrlimit(RLIMIT_NOFILE, &rlimit)); - /* bump fs.nr_open */ - n2 = sprintf(buf2, "%d\n", nr_open + 1024); + rlimit_max = rlimit.rlim_max; + + /* bump rlimit.rlim_max */ + n2 = sprintf(buf2, "%d\n", rlimit_max + 1024); lseek(fd, 0, SEEK_SET); write(fd, buf2, n2); /* bump ulimit -n */ - rlimit.rlim_cur = nr_open + 1024; - rlimit.rlim_max = nr_open + 1024; + rlimit.rlim_cur = rlimit_max + 1024; + rlimit.rlim_max = rlimit_max + 1024; EXPECT_EQ(0, setrlimit(RLIMIT_NOFILE, &rlimit)) { lseek(fd, 0, SEEK_SET); write(fd, buf, n); exit(EXIT_FAILURE); } - /* get a descriptor past the old fs.nr_open */ - EXPECT_GE(dup2(2, nr_open + 64), 0) { + /* get a descriptor past the old rlimit.rlim_max */ + EXPECT_GE(dup2(2, rlimit_max + 64), 0) { lseek(fd, 0, SEEK_SET); write(fd, buf, n); exit(EXIT_FAILURE); @@ -74,15 +77,20 @@ TEST(unshare_EMFILE) if (pid == 0) { int err; - /* restore fs.nr_open */ + n3 = sprintf(buf3, "%d\n", rlimit_max); lseek(fd, 0, SEEK_SET); - write(fd, buf, n); + write(fd, buf3, n3); + /* ... and now unshare(CLONE_FILES) must fail with EMFILE */ err = unshare(CLONE_FILES); EXPECT_EQ(err, -1) exit(EXIT_FAILURE); EXPECT_EQ(errno, EMFILE) exit(EXIT_FAILURE); + + /* restore fs.nr_open */ + lseek(fd, 0, SEEK_SET); + write(fd, buf, n); exit(EXIT_SUCCESS); }
Set maximum file descriptor number limit by rlimit.rlim_max than nr_open(hard limit). Hard limit may cause dup2 fail. Signed-off-by: lufei <lufei@uniontech.com> --- tools/testing/selftests/core/unshare_test.c | 28 +++++++++++++-------- 1 file changed, 18 insertions(+), 10 deletions(-)