well, i checked the script using checkpatch.pl and
it shows that the patch has no warnings or errors
and its ready to be sent
v2:
- fixed multiple trailing whitespace errors and
- the Signed-off-by mismatch
The test file for the IR decoder used single-line comments
at the top to document its purpose and licensing,
which is inconsistent with the style used throughout the
Linux kernel.
In this patch i converted the file header to
a proper multi-line comment block
(/*) that aligns with standard kernel practices.
This improves readability, consistency across selftests,
and ensures the license and documentation are
clearly visible in a familiar format.
No functional changes have been made.
Signed-off-by: Abdelrahman Fekry <abdelrahmanfekry375(a)gmail.com>
---
tools/testing/selftests/ir/ir_loopback.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/ir/ir_loopback.c b/tools/testing/selftests/ir/ir_loopback.c
index f4a15cbdd5ea..c94faa975630 100644
--- a/tools/testing/selftests/ir/ir_loopback.c
+++ b/tools/testing/selftests/ir/ir_loopback.c
@@ -1,14 +1,17 @@
// SPDX-License-Identifier: GPL-2.0
-// test ir decoder
-//
-// Copyright (C) 2018 Sean Young <sean(a)mess.org>
-
-// When sending LIRC_MODE_SCANCODE, the IR will be encoded. rc-loopback
-// will send this IR to the receiver side, where we try to read the decoded
-// IR. Decoding happens in a separate kernel thread, so we will need to
-// wait until that is scheduled, hence we use poll to check for read
-// readiness.
-
+/* Copyright (C) 2018 Sean Young <sean(a)mess.org>
+ *
+ * Selftest for IR decoder
+ *
+ *
+ * When sending LIRC_MODE_SCANCODE, the IR will be encoded.
+ * rc-loopback will send this IR to the receiver side,
+ * where we try to read the decoded IR.
+ * Decoding happens in a separate kernel thread,
+ * so we will need to wait until that is scheduled,
+ * hence we use poll to check for read
+ * readiness.
+ */
#include <linux/lirc.h>
#include <errno.h>
#include <stdio.h>
--
2.25.1
This improves the expressiveness of unprivileged BPF by inserting
speculation barriers instead of rejecting the programs.
The approach was previously presented at LPC'24 [1] and RAID'24 [2].
To mitigate the Spectre v1 (PHT) vulnerability, the kernel rejects
potentially-dangerous unprivileged BPF programs as of
commit 9183671af6db ("bpf: Fix leakage under speculation on mispredicted
branches"). In [2], we have analyzed 364 object files from open source
projects (Linux Samples and Selftests, BCC, Loxilb, Cilium, libbpf
Examples, Parca, and Prevail) and found that this affects 31% to 54% of
programs.
To resolve this in the majority of cases this patchset adds a fall-back
for mitigating Spectre v1 using speculation barriers. The kernel still
optimistically attempts to verify all speculative paths but uses
speculation barriers against v1 when unsafe behavior is detected. This
allows for more programs to be accepted without disabling the BPF
Spectre mitigations (e.g., by setting cpu_mitigations_off()).
For this, it relies on the fact that speculation barriers prevent all
later instructions if the speculation was not correct:
* On x86_64, lfence acts as full speculation barrier, not only as a
load fence [3]:
An LFENCE instruction or a serializing instruction will ensure that
no later instructions execute, even speculatively, until all prior
instructions complete locally. [...] Inserting an LFENCE instruction
after a bounds check prevents later operations from executing before
the bound check completes.
This was experimentally confirmed in [4].
* ARM's SB speculation barrier instruction also affects "any instruction
that appears later in the program order than the barrier" [5].
In [1] we have measured the overhead of this approach relative to having
mitigations off and including the upstream Spectre v4 mitigations. For
event tracing and stack-sampling profilers, we found that mitigations
increase BPF program execution time by 0% to 62%. For the Loxilb network
load balancer, we have measured a 14% slowdown in SCTP performance but
no significant slowdown for TCP. This overhead only applies to programs
that were previously rejected.
I reran the expressiveness-evaluation with v6.14 and made sure the main
results still match those from [1] and [2] (which used v6.5).
Main design decisions are:
* Do not use separate bytecode insns for v1 and v4 barriers (inspired by
Daniel Borkmann's question at LPC). This simplifies the verifier
significantly and has the only downside that performance on PowerPC is
not as high as it could be.
* Allow archs to still disable v1/v4 mitigations separately by setting
bpf_jit_bypass_spec_v1/v4(). This has the benefit that archs can
benefit from improved BPF expressiveness / performance if they are not
vulnerable (e.g., ARM64 for v4 in the kernel).
* Do not remove the empty BPF_NOSPEC implementation for backends for
which it is unknown whether they are vulnerable to Spectre v1.
[1] https://lpc.events/event/18/contributions/1954/ ("Mitigating
Spectre-PHT using Speculation Barriers in Linux eBPF")
[2] https://arxiv.org/pdf/2405.00078 ("VeriFence: Lightweight and
Precise Spectre Defenses for Untrusted Linux Kernel Extensions")
[3] https://www.intel.com/content/www/us/en/developer/articles/technical/softwa…
("Managed Runtime Speculative Execution Side Channel Mitigations")
[4] https://dl.acm.org/doi/pdf/10.1145/3359789.3359837 ("Speculator: a
tool to analyze speculative execution attacks and mitigations" -
Section 4.6 "Stopping Speculative Execution")
[5] https://developer.arm.com/documentation/ddi0597/2020-12/Base-Instructions/S…
("SB - Speculation Barrier - Arm Armv8-A A32/T32 Instruction Set Architecture (2020-12)")
Changes:
* v2 -> v3:
- Fix
https://lore.kernel.org/oe-kbuild-all/202504212030.IF1SLhz6-lkp@intel.com/
and similar by moving the bpf_jit_bypass_spec_v1/v4() prototypes out
of the #ifdef CONFIG_BPF_SYSCALL. Decided not to move them to
filter.h (where similar bpf_jit_*() prototypes live) as they would
still have to be duplicated in bpf.h to be usable to
bpf_bypass_spec_v1/v4() (unless including filter.h in bpf.h is an
option).
- Fix
https://lore.kernel.org/oe-kbuild-all/202504220035.SoGveGpj-lkp@intel.com/
by moving the variable declarations out of the switch-case.
- Build touched C files with W=2 and bpf config on x86 to check that
there are no other warnings introduced.
- Found 3 more checkpatch warnings that can be fixed without degrading
readability.
- Rebase to bpf-next 2025-05-01
- Link to v2: https://lore.kernel.org/bpf/20250421091802.3234859-1-luis.gerhorst@fau.de/
* v1 -> v2:
- Drop former commits 9 ("bpf: Return PTR_ERR from push_stack()") and 11
("bpf: Fall back to nospec for spec path verification") as suggested
by Alexei. This series therefore no longer changes push_stack() to
return PTR_ERR.
- Add detailed explanation of how lfence works internally and how it
affects the algorithm.
- Add tests checking that nospec instructions are inserted in expected
locations using __xlated_unpriv as suggested by Eduard (also,
include a fix for __xlated_unpriv)
- Add a test for the mitigations from the description of
commit 9183671af6db ("bpf: Fix leakage under speculation on
mispredicted branches")
- Remove unused variables from do_check[_insn]() as suggested by
Eduard.
- Remove INSN_IDX_MODIFIED to improve readability as suggested by
Eduard. This also causes the nospec_result-check to run (and fail)
for jumping-ops. Add a warning to assert that this check must never
succeed in that case.
- Add details on the safety of patch 10 ("bpf: Allow nospec-protected
var-offset stack access") based on the feedback on v1.
- Rebase to bpf-next-250420
- Link to v1: https://lore.kernel.org/all/20250313172127.1098195-1-luis.gerhorst@fau.de/
* RFC -> v1:
- rebase to bpf-next-250313
- tests: mark expected successes/new errors
- add bpt_jit_bypass_spec_v1/v4() to avoid #ifdef in
bpf_bypass_spec_v1/v4()
- ensure that nospec with v1-support is implemented for archs for
which GCC supports speculation barriers, except for MIPS
- arm64: emit speculation barrier
- powerpc: change nospec to include v1 barrier
- discuss potential security (archs that do not impl. BPF nospec) and
performance (only PowerPC) regressions
- Link to RFC: https://lore.kernel.org/bpf/20250224203619.594724-1-luis.gerhorst@fau.de/
Luis Gerhorst (11):
selftests/bpf: Fix caps for __xlated/jited_unpriv
bpf: Move insn if/else into do_check_insn()
bpf: Return -EFAULT on misconfigurations
bpf: Return -EFAULT on internal errors
bpf, arm64, powerpc: Add bpf_jit_bypass_spec_v1/v4()
bpf, arm64, powerpc: Change nospec to include v1 barrier
bpf: Rename sanitize_stack_spill to nospec_result
bpf: Fall back to nospec for Spectre v1
selftests/bpf: Add test for Spectre v1 mitigation
bpf: Allow nospec-protected var-offset stack access
bpf: Fall back to nospec for sanitization-failures
arch/arm64/net/bpf_jit.h | 5 +
arch/arm64/net/bpf_jit_comp.c | 28 +-
arch/powerpc/net/bpf_jit_comp64.c | 80 ++-
include/linux/bpf.h | 11 +-
include/linux/bpf_verifier.h | 3 +-
include/linux/filter.h | 2 +-
kernel/bpf/core.c | 32 +-
kernel/bpf/verifier.c | 653 ++++++++++--------
tools/testing/selftests/bpf/progs/bpf_misc.h | 4 +
.../selftests/bpf/progs/verifier_and.c | 8 +-
.../selftests/bpf/progs/verifier_bounds.c | 66 +-
.../bpf/progs/verifier_bounds_deduction.c | 45 +-
.../selftests/bpf/progs/verifier_map_ptr.c | 20 +-
.../selftests/bpf/progs/verifier_movsx.c | 16 +-
.../selftests/bpf/progs/verifier_unpriv.c | 65 +-
.../bpf/progs/verifier_value_ptr_arith.c | 101 ++-
tools/testing/selftests/bpf/test_loader.c | 14 +-
.../selftests/bpf/verifier/dead_code.c | 3 +-
tools/testing/selftests/bpf/verifier/jmp32.c | 33 +-
tools/testing/selftests/bpf/verifier/jset.c | 10 +-
20 files changed, 771 insertions(+), 428 deletions(-)
base-commit: 358b1c0f56ebb6996fcec7dcdcf6bae5dcbc8b6c
--
2.49.0
The BTF dumper code currently displays arrays of characters as just that -
arrays, with each character formatted individually. Sometimes this is what
makes sense, but it's nice to be able to treat that array as a string.
This change adds a special case to the btf_dump functionality to allow
arrays of single-byte integer values to be printed as character strings.
Characters for which isprint() returns false are printed as hex-escaped
values. This is enabled when the new ".emit_strings" is set to 1 in the
btf_dump_type_data_opts structure.
As an example, here's what it looks like to dump the string "hello" using
a few different field values for btf_dump_type_data_opts (.compact = 1):
- .emit_strings = 0, .skip_names = 0: (char[6])['h','e','l','l','o',]
- .emit_strings = 0, .skip_names = 1: ['h','e','l','l','o',]
- .emit_strings = 1, .skip_names = 0: (char[6])"hello"
- .emit_strings = 1, .skip_names = 1: "hello"
Here's the string "h\xff", dumped with .compact = 1 and .skip_names = 1:
- .emit_strings = 0: ['h',-1,]
- .emit_strings = 1: "h\xff"
Signed-off-by: Blake Jones <blakejones(a)google.com>
---
tools/lib/bpf/btf.h | 3 ++-
tools/lib/bpf/btf_dump.c | 44 +++++++++++++++++++++++++++++++++++++++-
2 files changed, 45 insertions(+), 2 deletions(-)
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 4392451d634b..ccfd905f03df 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -326,9 +326,10 @@ struct btf_dump_type_data_opts {
bool compact; /* no newlines/indentation */
bool skip_names; /* skip member/type names */
bool emit_zeroes; /* show 0-valued fields */
+ bool emit_strings; /* print char arrays as strings */
size_t :0;
};
-#define btf_dump_type_data_opts__last_field emit_zeroes
+#define btf_dump_type_data_opts__last_field emit_strings
LIBBPF_API int
btf_dump__dump_type_data(struct btf_dump *d, __u32 id,
diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index 460c3e57fadb..336a6646e0fa 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -68,6 +68,7 @@ struct btf_dump_data {
bool compact;
bool skip_names;
bool emit_zeroes;
+ bool emit_strings;
__u8 indent_lvl; /* base indent level */
char indent_str[BTF_DATA_INDENT_STR_LEN];
/* below are used during iteration */
@@ -2028,6 +2029,43 @@ static int btf_dump_var_data(struct btf_dump *d,
return btf_dump_dump_type_data(d, NULL, t, type_id, data, 0, 0);
}
+static int btf_dump_string_data(struct btf_dump *d,
+ const struct btf_type *t,
+ __u32 id,
+ const void *data)
+{
+ const struct btf_array *array = btf_array(t);
+ __u32 i;
+
+ btf_dump_data_pfx(d);
+ btf_dump_printf(d, "\"");
+
+ for (i = 0; i < array->nelems; i++, data++) {
+ char c;
+
+ if (data >= d->typed_dump->data_end)
+ return -E2BIG;
+
+ c = *(char *)data;
+ if (c == '\0') {
+ /*
+ * When printing character arrays as strings, NUL bytes
+ * are always treated as string terminators; they are
+ * never printed.
+ */
+ break;
+ }
+ if (isprint(c))
+ btf_dump_printf(d, "%c", c);
+ else
+ btf_dump_printf(d, "\\x%02x", *(__u8 *)data);
+ }
+
+ btf_dump_printf(d, "\"");
+
+ return 0;
+}
+
static int btf_dump_array_data(struct btf_dump *d,
const struct btf_type *t,
__u32 id,
@@ -2055,8 +2093,11 @@ static int btf_dump_array_data(struct btf_dump *d,
* char arrays, so if size is 1 and element is
* printable as a char, we'll do that.
*/
- if (elem_size == 1)
+ if (elem_size == 1) {
+ if (d->typed_dump->emit_strings)
+ return btf_dump_string_data(d, t, id, data);
d->typed_dump->is_array_char = true;
+ }
}
/* note that we increment depth before calling btf_dump_print() below;
@@ -2544,6 +2585,7 @@ int btf_dump__dump_type_data(struct btf_dump *d, __u32 id,
d->typed_dump->compact = OPTS_GET(opts, compact, false);
d->typed_dump->skip_names = OPTS_GET(opts, skip_names, false);
d->typed_dump->emit_zeroes = OPTS_GET(opts, emit_zeroes, false);
+ d->typed_dump->emit_strings = OPTS_GET(opts, emit_strings, false);
ret = btf_dump_dump_type_data(d, NULL, t, id, data, 0, 0);
--
2.49.0.1204.g71687c7c1d-goog
Add missing config options for the tso.py test, specifically
to make sure the kernel is built with vxlan and gre tunnels.
I noticed this while adding a TSO-capable device QEMU to the CI.
Previously we only run virtio tests and it doesn't report LSO
stats on the QEMU we have.
Fixes: 0d0f4174f6c8 ("selftests: drv-net: add a simple TSO test")
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
---
CC: shuah(a)kernel.org
CC: willemb(a)google.com
CC: linux-kselftest(a)vger.kernel.org
---
tools/testing/selftests/drivers/net/hw/config | 6 ++++++
1 file changed, 6 insertions(+)
create mode 100644 tools/testing/selftests/drivers/net/hw/config
diff --git a/tools/testing/selftests/drivers/net/hw/config b/tools/testing/selftests/drivers/net/hw/config
new file mode 100644
index 000000000000..ea4b70d71563
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/hw/config
@@ -0,0 +1,6 @@
+CONFIG_IPV6=y
+CONFIG_IPV6_GRE=y
+CONFIG_NET_IP_TUNNEL=y
+CONFIG_NET_IPGRE=y
+CONFIG_NET_IPGRE_DEMUX=y
+CONFIG_VXLAN=y
--
2.49.0
We have the logic to include net/lib automatically for net related
selftests. However, currently, this logic is only in install target
which means only `make install` will have net/lib included. This commit
adds the logic to all target so that all `make`, `make run_tests` and
`make install` will have net/lib included in net related selftests.
Signed-off-by: Bui Quang Minh <minhquangbui99(a)gmail.com>
---
Changes in v3:
- Don't remove INSTALL_DEP_TARGETS in install target so that net/lib is
copied to INSTALL_PATH
Changes in v2:
- Make the commit message clearer.
tools/testing/selftests/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 6aa11cd3db42..339b31e6a6b5 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -205,7 +205,7 @@ export KHDR_INCLUDES
all:
@ret=1; \
- for TARGET in $(TARGETS); do \
+ for TARGET in $(TARGETS) $(INSTALL_DEP_TARGETS); do \
BUILD_TARGET=$$BUILD/$$TARGET; \
mkdir $$BUILD_TARGET -p; \
$(MAKE) OUTPUT=$$BUILD_TARGET -C $$TARGET \
--
2.43.0
This reverts commit a571a9a1b120264e24b41eddf1ac5140131bfa84.
The commit in question breaks kunit for older compilers:
$ gcc --version
gcc (GCC) 11.5.0 20240719 (Red Hat 11.5.0-5)
$ ./tools/testing/kunit/kunit.py run --alltests --json --arch=x86_64
Configuring KUnit Kernel ...
Regenerating .config ...
Populating config with:
$ make ARCH=x86_64 O=.kunit olddefconfig
ERROR:root:Not all Kconfig options selected in kunitconfig were in the generated .config.
This is probably due to unsatisfied dependencies.
Missing: CONFIG_INIT_STACK_ALL_PATTERN=y
Link: https://lore.kernel.org/20250529083811.778bc31b@kernel.org
Fixes: a571a9a1b120 ("kunit: configs: Enable CONFIG_INIT_STACK_ALL_PATTERN in all_tests")
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
---
I'd like to take this in via netdev since it fixes our CI.
We'll send it to Linus next week.
CC: brendan.higgins(a)linux.dev
CC: davidgow(a)google.com
CC: rmoar(a)google.com
CC: broonie(a)kernel.org
CC: rf(a)opensource.cirrus.com
CC: mic(a)digikod.net
CC: skhan(a)linuxfoundation.org
CC: linux-kselftest(a)vger.kernel.org
CC: kunit-dev(a)googlegroups.com
---
tools/testing/kunit/configs/all_tests.config | 1 -
1 file changed, 1 deletion(-)
diff --git a/tools/testing/kunit/configs/all_tests.config b/tools/testing/kunit/configs/all_tests.config
index 48b132cd9d2a..2f093048d985 100644
--- a/tools/testing/kunit/configs/all_tests.config
+++ b/tools/testing/kunit/configs/all_tests.config
@@ -10,7 +10,6 @@ CONFIG_KUNIT_EXAMPLE_TEST=y
CONFIG_KUNIT_ALL_TESTS=y
CONFIG_FORTIFY_SOURCE=y
-CONFIG_INIT_STACK_ALL_PATTERN=y
CONFIG_IIO=y
--
2.49.0