On Fri, 2026-06-05 at 03:31 -0700, Breno Leitao wrote: > Add a kselftest that exercises the RDS getsockopt() paths converted to > the getsockopt_iter() / sockopt_t callback: > > - RDS_RECVERR and SO_RDS_TRANSPORT, which return their int value through > copy_to_iter() and report the written length in opt->optlen. > > - RDS_INFO_*, which obtains the userspace buffer pages with > iov_iter_extract_pages() (including a non-zero starting page offset) > and lets the info producers copy the snapshot in under a spinlock. > > Signed-off-by: Breno Leitao <[email protected]> Hi Breno,
This looks great, thanks for the updates. I noticed this morning though that this patch has a conflict in the Makefile on the latest net-next. Commit 6d05d3cb44c5 renames run.sh to rds_run.sh. So you'll need to rebase for this patch to apply cleanly. Also, since the cover letter mentions vibe coding on this patch, I checked Documentation/process/coding-assistants.rst for AI assisted patch procedures. Per the documentation, this patch should carry an Assisted-By tag that identifies the model, eg: Assisted-by: <tool>:<model-version> Other than that, this patch looks good to me. With the above fixed, you can add my RVB: Reviewed-by: Allison Henderson <[email protected]> Thanks! Allison > --- > tools/testing/selftests/net/rds/.gitignore | 1 + > tools/testing/selftests/net/rds/Makefile | 4 + > tools/testing/selftests/net/rds/getsockopt.c | 208 > +++++++++++++++++++++++++++ > 3 files changed, 213 insertions(+) > > diff --git a/tools/testing/selftests/net/rds/.gitignore > b/tools/testing/selftests/net/rds/.gitignore > index 1c6f04e2aa11..7ca4b1440f51 100644 > --- a/tools/testing/selftests/net/rds/.gitignore > +++ b/tools/testing/selftests/net/rds/.gitignore > @@ -1 +1,2 @@ > include.sh > +getsockopt > diff --git a/tools/testing/selftests/net/rds/Makefile > b/tools/testing/selftests/net/rds/Makefile > index fe363be8e358..0700d8298eec 100644 > --- a/tools/testing/selftests/net/rds/Makefile > +++ b/tools/testing/selftests/net/rds/Makefile > @@ -5,6 +5,8 @@ all: > > TEST_PROGS := run.sh > > +TEST_GEN_PROGS := getsockopt > + > TEST_FILES := \ > include.sh \ > settings \ > @@ -16,4 +18,6 @@ EXTRA_CLEAN := \ > /tmp/rds_logs \ > # end of EXTRA_CLEAN > > +CFLAGS += $(KHDR_INCLUDES) > + > include ../../lib.mk > diff --git a/tools/testing/selftests/net/rds/getsockopt.c > b/tools/testing/selftests/net/rds/getsockopt.c > new file mode 100644 > index 000000000000..93ff252c69b8 > --- /dev/null > +++ b/tools/testing/selftests/net/rds/getsockopt.c > @@ -0,0 +1,208 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Exercise the RDS getsockopt() paths that were converted to the > + * getsockopt_iter() / sockopt_t callback. > + * > + * Three distinct paths are covered: > + * > + * - RDS_RECVERR and SO_RDS_TRANSPORT, which now return their int value > + * through copy_to_iter() and report the written length in opt->optlen. > + * > + * - RDS_INFO_*, which pins the userspace buffer with > + * iov_iter_extract_pages() (including a non-zero starting page offset) > + * and lets the info producers memcpy the snapshot in under a spinlock. > + * > + * The kvec (in-kernel buffer) -> -EOPNOTSUPP path of rds_info_getsockopt() > + * is not reachable from a userspace getsockopt() and so is not tested here. > + */ > +#include <errno.h> > +#include <stdint.h> > +#include <string.h> > +#include <unistd.h> > +#include <sys/mman.h> > +#include <sys/socket.h> > +#include <linux/rds.h> > + > +#include "../../kselftest_harness.h" > + > +#ifndef AF_RDS > +#define AF_RDS 21 > +#endif > + > +FIXTURE(rds) { > + int fd; > +}; > + > +FIXTURE_SETUP(rds) > +{ > + self->fd = socket(AF_RDS, SOCK_SEQPACKET, 0); > + if (self->fd < 0) > + SKIP(return, "AF_RDS unavailable (errno %d) - load the rds > module", > + errno); > +} > + > +FIXTURE_TEARDOWN(rds) > +{ > + if (self->fd >= 0) > + close(self->fd); > +} > + > +/* RDS_RECVERR defaults to 0 and is reported back as a 4-byte int. */ > +TEST_F(rds, recverr_default) > +{ > + socklen_t len = sizeof(int); > + int val = 0xdeadbeef; > + > + ASSERT_EQ(0, getsockopt(self->fd, SOL_RDS, RDS_RECVERR, &val, &len)); > + EXPECT_EQ(sizeof(int), len); > + EXPECT_EQ(0, val); > +} > + > +/* A value set via setsockopt() must be readable back unchanged. */ > +TEST_F(rds, recverr_set_get) > +{ > + socklen_t len = sizeof(int); > + int val = 1; > + > + ASSERT_EQ(0, setsockopt(self->fd, SOL_RDS, RDS_RECVERR, &val, len)); > + > + val = 0; > + ASSERT_EQ(0, getsockopt(self->fd, SOL_RDS, RDS_RECVERR, &val, &len)); > + EXPECT_EQ(sizeof(int), len); > + EXPECT_EQ(1, val); > +} > + > +/* A buffer smaller than an int is rejected with EINVAL, not silently. */ > +TEST_F(rds, recverr_short_buffer) > +{ > + socklen_t len = sizeof(int) - 1; > + char buf[sizeof(int)]; > + > + EXPECT_EQ(-1, getsockopt(self->fd, SOL_RDS, RDS_RECVERR, buf, &len)); > + EXPECT_EQ(EINVAL, errno); > +} > + > +/* An unbound socket reports RDS_TRANS_NONE for SO_RDS_TRANSPORT. */ > +TEST_F(rds, transport_unbound) > +{ > + socklen_t len = sizeof(int); > + int val = 0; > + > + ASSERT_EQ(0, getsockopt(self->fd, SOL_RDS, SO_RDS_TRANSPORT, &val, > + &len)); > + EXPECT_EQ(sizeof(int), len); > + EXPECT_EQ(RDS_TRANS_NONE, (unsigned int)val); > +} > + > +TEST_F(rds, transport_short_buffer) > +{ > + socklen_t len = sizeof(int) - 1; > + char buf[sizeof(int)]; > + > + EXPECT_EQ(-1, getsockopt(self->fd, SOL_RDS, SO_RDS_TRANSPORT, buf, > + &len)); > + EXPECT_EQ(EINVAL, errno); > +} > + > +/* > + * RDS_INFO_COUNTERS with a zero-length buffer is the "probe" call: it must > + * fail with ENOSPC and report the required snapshot size in optlen. > + */ > +TEST_F(rds, info_counters_probe) > +{ > + socklen_t len = 0; > + > + EXPECT_EQ(-1, getsockopt(self->fd, SOL_RDS, RDS_INFO_COUNTERS, NULL, > + &len)); > + EXPECT_EQ(ENOSPC, errno); > + EXPECT_GT(len, 0); > + /* The snapshot is an array of fixed-size counter records. */ > + EXPECT_EQ(0, len % (socklen_t)sizeof(struct rds_info_counter)); > +} > + > +/* > + * A real snapshot into an unaligned userspace buffer exercises the > + * iov_iter_extract_pages() path, including the non-zero offset0 handling > + * that the patch reworked. Place the buffer at a non-page-aligned address > + * spanning into the next page to make sure multi-page pinning works too. > + */ > +TEST_F(rds, info_counters_snapshot) > +{ > + struct rds_info_counter *ctr; > + socklen_t need = 0, len; > + long pagesz = sysconf(_SC_PAGESIZE); > + size_t offset, map_len; > + unsigned int i, n; > + char *region, *buf; > + int ret; > + > + /* Probe for the required size. */ > + getsockopt(self->fd, SOL_RDS, RDS_INFO_COUNTERS, NULL, &need); > + ASSERT_GT(need, 0); > + > + /* > + * Place the buffer at a non-page-aligned offset that runs past the > + * first page boundary, and size the mapping from the probed length so > + * the test keeps working if the counter set grows. > + */ > + offset = pagesz - 64; > + map_len = ((offset + need + pagesz - 1) / pagesz) * pagesz; > + > + region = mmap(NULL, map_len, PROT_READ | PROT_WRITE, > + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); > + ASSERT_NE(MAP_FAILED, region); > + > + buf = region + offset; > + > + /* > + * On success the RDS_INFO path returns the positive per-element size > + * (lens.each) rather than 0, and writes the full snapshot length back > + * into optlen. > + */ > + len = need; > + ret = getsockopt(self->fd, SOL_RDS, RDS_INFO_COUNTERS, buf, &len); > + ASSERT_GE(ret, 0) { > + TH_LOG("getsockopt snapshot failed: errno %d", errno); > + } > + EXPECT_EQ(sizeof(struct rds_info_counter), ret); > + EXPECT_EQ(need, len); > + > + /* The counter names must be NUL-terminated, non-empty strings. */ > + ctr = (struct rds_info_counter *)buf; > + n = len / sizeof(*ctr); > + ASSERT_GT(n, 0); > + for (i = 0; i < n; i++) { > + size_t namelen = strnlen((char *)ctr[i].name, > + sizeof(ctr[i].name)); > + > + EXPECT_GT(namelen, 0); > + EXPECT_LT(namelen, sizeof(ctr[i].name)); > + } > + > + munmap(region, map_len); > +} > + > +/* > + * A non-zero but too-small buffer must report ENOSPC and the full required > + * length, without corrupting memory past the buffer. > + */ > +TEST_F(rds, info_counters_short_buffer) > +{ > + socklen_t need = 0, len; > + char small[sizeof(struct rds_info_counter)]; > + > + getsockopt(self->fd, SOL_RDS, RDS_INFO_COUNTERS, NULL, &need); > + ASSERT_GT(need, 0); > + > + /* Ask with a buffer guaranteed smaller than the full snapshot. */ > + if (need <= (socklen_t)sizeof(small)) > + SKIP(return, "snapshot fits in one record; nothing to test"); > + > + len = 1; /* < sizeof(struct rds_info_counter) */ > + EXPECT_EQ(-1, getsockopt(self->fd, SOL_RDS, RDS_INFO_COUNTERS, small, > + &len)); > + EXPECT_EQ(ENOSPC, errno); > + EXPECT_EQ(need, len); > +} > + > +TEST_HARNESS_MAIN >
