June 2025 - Linux-kselftest-mirror

[RFC PATCH v2 0/9] KVM: Enable Nested Virt selftests

by Ganapatrao Kulkarni

This patch series makes the selftest work with NV enabled. The guest code is run in vEL2 instead of EL1. We add a command line option to enable testing of NV. The NV tests are disabled by default. Modified around 12 selftests in this series. Changes since v1: - Updated NV helper functions as per comments [1]. - Modified existing testscases to run guest code in vEL2. [1] https://lkml.iu.edu/hypermail/linux/kernel/2502.0/07001.html Ganapatrao Kulkarni (9): KVM: arm64: nv: selftests: Add support to run guest code in vEL2. KVM: arm64: nv: selftests: Add simple test to run guest code in vEL2 KVM: arm64: nv: selftests: Enable hypervisor timer tests to run in vEL2 KVM: arm64: nv: selftests: enable aarch32_id_regs test to run in vEL2 KVM: arm64: nv: selftests: Enable vgic tests to run in vEL2 KVM: arm64: nv: selftests: Enable set_id_regs test to run in vEL2 KVM: arm64: nv: selftests: Enable test to run in vEL2 KVM: selftests: arm64: Extend kvm_page_table_test to run guest code in vEL2 KVM: arm64: nv: selftests: Enable page_fault_test test to run in vEL2 tools/testing/selftests/kvm/Makefile.kvm | 2 + tools/testing/selftests/kvm/arch_timer.c | 8 +- .../selftests/kvm/arm64/aarch32_id_regs.c | 34 ++++- .../testing/selftests/kvm/arm64/arch_timer.c | 118 +++++++++++++++--- .../selftests/kvm/arm64/nv_guest_hypervisor.c | 68 ++++++++++ .../selftests/kvm/arm64/page_fault_test.c | 35 +++++- .../testing/selftests/kvm/arm64/set_id_regs.c | 57 ++++++++- tools/testing/selftests/kvm/arm64/vgic_init.c | 54 +++++++- tools/testing/selftests/kvm/arm64/vgic_irq.c | 27 ++-- .../selftests/kvm/arm64/vgic_lpi_stress.c | 19 ++- .../testing/selftests/kvm/guest_print_test.c | 32 +++++ .../selftests/kvm/include/arm64/arch_timer.h | 16 +++ .../kvm/include/arm64/kvm_util_arch.h | 3 + .../selftests/kvm/include/arm64/nv_util.h | 45 +++++++ .../selftests/kvm/include/arm64/vgic.h | 1 + .../testing/selftests/kvm/include/kvm_util.h | 3 + .../selftests/kvm/include/timer_test.h | 1 + .../selftests/kvm/kvm_page_table_test.c | 30 ++++- tools/testing/selftests/kvm/lib/arm64/nv.c | 46 +++++++ .../selftests/kvm/lib/arm64/processor.c | 61 ++++++--- tools/testing/selftests/kvm/lib/arm64/vgic.c | 8 ++ 21 files changed, 604 insertions(+), 64 deletions(-) create mode 100644 tools/testing/selftests/kvm/arm64/nv_guest_hypervisor.c create mode 100644 tools/testing/selftests/kvm/include/arm64/nv_util.h create mode 100644 tools/testing/selftests/kvm/lib/arm64/nv.c -- 2.48.1

1 hour, 16 minutes

6
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[PATCH] libbpf: add support for printing BTF character arrays as strings

by Blake Jones

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 ".print_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): - .print_strings = 0, .skip_names = 0: (char[6])['h','e','l','l','o',] - .print_strings = 0, .skip_names = 1: ['h','e','l','l','o',] - .print_strings = 1, .skip_names = 0: (char[6])"hello" - .print_strings = 1, .skip_names = 1: "hello" Here's the string "h\xff", dumped with .compact = 1 and .skip_names = 1: - .print_strings = 0: ['h',-1,] - .print_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 | 51 ++++++++- .../selftests/bpf/prog_tests/btf_dump.c | 102 ++++++++++++++++++ 3 files changed, 154 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index 4392451d634b..be8e8e26d245 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 print_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 print_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..a07dd5accdd8 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -75,6 +75,7 @@ struct btf_dump_data { bool is_array_member; bool is_array_terminated; bool is_array_char; + bool print_strings; }; struct btf_dump { @@ -2028,6 +2029,50 @@ 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; + + if (!btf_is_int(skip_mods_and_typedefs(d->btf, array->type, NULL)) || + btf__resolve_size(d->btf, array->type) != 1 || + !d->typed_dump->print_strings) { + pr_warn("unexpected %s() call for array type %u\n", + __func__, array->type); + return -EINVAL; + } + + 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 +2100,11 @@ 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->print_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 +2592,7 @@ 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->print_strings = OPTS_GET(opts, print_strings, false); ret = btf_dump_dump_type_data(d, NULL, t, id, data, 0, 0); diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dump.c b/tools/testing/selftests/bpf/prog_tests/btf_dump.c index c0a776feec23..70e51943f148 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf_dump.c +++ b/tools/testing/selftests/bpf/prog_tests/btf_dump.c @@ -879,6 +879,106 @@ static void test_btf_dump_var_data(struct btf *btf, struct btf_dump *d, "static int bpf_cgrp_storage_busy = (int)2", 2); } +/* + * String-like types are generally not named, so they need to be + * found this way rather than via btf__find_by_name(). + */ +static int find_char_array_type(struct btf *btf, int nelems) +{ + const int nr_types = btf__type_cnt(btf); + const int char_type = btf__find_by_name(btf, "char"); + + for (int i = 1; i < nr_types; i++) { + const struct btf_type *t; + const struct btf_array *at; + + t = btf__type_by_id(btf, i); + if (btf_kind(t) != BTF_KIND_ARRAY) + continue; + + at = btf_array(t); + if (at->nelems == nelems && at->type == char_type) + return i; + } + + return -ENOENT; +} + +static int btf_dump_string_data(struct btf *btf, struct btf_dump *d, + char *str, struct btf_dump_type_data_opts *opts, + char *ptr, size_t ptr_sz, + const char *expected_val) +{ + char name[64]; + size_t type_sz; + int type_id; + int ret = 0; + + snprintf(name, sizeof(name), "char[%zu]", ptr_sz); + type_id = find_char_array_type(btf, ptr_sz); + if (!ASSERT_GE(type_id, 0, "find type id")) + return -ENOENT; + type_sz = btf__resolve_size(btf, type_id); + str[0] = '\0'; + ret = btf_dump__dump_type_data(d, type_id, ptr, ptr_sz, opts); + if (type_sz <= ptr_sz) { + if (!ASSERT_EQ(ret, type_sz, "failed/unexpected type_sz")) + return -EINVAL; + } else { + if (!ASSERT_EQ(ret, -E2BIG, "failed to return -E2BIG")) + return -EINVAL; + } + if (!ASSERT_STREQ(str, expected_val, "ensure expected/actual match")) + return -EFAULT; + return 0; +} + +static void test_btf_dump_string_data(struct btf *btf, struct btf_dump *d, + char *str) +{ + DECLARE_LIBBPF_OPTS(btf_dump_type_data_opts, opts); + + opts.compact = true; + opts.emit_zeroes = false; + opts.print_strings = true; + + opts.skip_names = false; + btf_dump_string_data(btf, d, str, &opts, "foo", 4, + "(char[4])\"foo\""); + + opts.skip_names = true; + btf_dump_string_data(btf, d, str, &opts, "foo", 4, + "\"foo\""); + + /* This should have no effect. */ + opts.emit_zeroes = false; + btf_dump_string_data(btf, d, str, &opts, "foo", 4, + "\"foo\""); + + /* This should have no effect. */ + opts.compact = false; + btf_dump_string_data(btf, d, str, &opts, "foo", 4, + "\"foo\""); + + /* Non-printable characters come out as hex. */ + btf_dump_string_data(btf, d, str, &opts, "fo\xff", 4, + "\"fo\\xff\""); + btf_dump_string_data(btf, d, str, &opts, "fo\x7", 4, + "\"fo\\x07\""); + + /* Should get printed properly even though there's no NUL. */ + char food[4] = { 'f', 'o', 'o', 'd' }; + + btf_dump_string_data(btf, d, str, &opts, food, 4, + "\"food\""); + + /* The embedded NUL should terminate the string. */ + char embed[4] = { 'f', 'o', '\0', 'd' }; + + btf_dump_string_data(btf, d, str, &opts, embed, 4, + "\"fo\""); +} + static void test_btf_datasec(struct btf *btf, struct btf_dump *d, char *str, const char *name, const char *expected_val, void *data, size_t data_sz) @@ -970,6 +1070,8 @@ void test_btf_dump() { test_btf_dump_struct_data(btf, d, str); if (test__start_subtest("btf_dump: var_data")) test_btf_dump_var_data(btf, d, str); + if (test__start_subtest("btf_dump: string_data")) + test_btf_dump_string_data(btf, d, str); btf_dump__free(d); btf__free(btf); -- 2.49.0.1204.g71687c7c1d-goog

1 hour, 49 minutes

3
2
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[PATCH net-next v2 0/4] netconsole: Optimize console registration and improve testing

by Breno Leitao

During performance analysis of console subsystem latency, I discovered that netconsole registers console handlers even when no active targets exist. These orphaned console handlers are invoked on every printk() call, get the lock, iterate through empty target lists, and consume CPU cycles without performing any useful work. This patch series addresses the inefficiency by: 1. Implementing dynamic console registration/unregistration based on target availability, ensuring console handlers are only active when needed 2. Adding automatic cleanup of unused console registrations when targets are disabled or removed 3. Extending the selftest suite to cover non-extended console format, which was previously untested The optimization reduces printk() overhead by eliminating unnecessary function calls and list traversals when netconsole targets are not configured, improving overall system performance during heavy logging scenarios. --- Changes in v2: - Added selftests to test the new mechanism - Unregister the console if the last target got disabled - Sending to net-next instead of net (Jakub) - Link to v1: https://lore.kernel.org/r/20250528-netcons_ext-v1-1-69f71e404e00@debian.org --- Breno Leitao (4): netconsole: Only register console drivers when targets are configured netconsole: Add automatic console unregistration on target removal selftests: netconsole: Do not exit from inside the validation function selftests: netconsole: Add support for basic netconsole target format drivers/net/netconsole.c | 61 +++++++++++++++++++--- .../selftests/drivers/net/lib/sh/lib_netcons.sh | 27 ++++++++-- .../testing/selftests/drivers/net/netcons_basic.sh | 50 +++++++++++------- 3 files changed, 107 insertions(+), 31 deletions(-) --- base-commit: 914873bc7df913db988284876c16257e6ab772c6 change-id: 20250528-netcons_ext-572982619bea Best regards, -- Breno Leitao <leitao(a)debian.org>

1 hour, 57 minutes

2
5
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[PATCH] lib/tests: Make FORTIFY_KUNIT_TEST depend on FORTIFY_SOURCE

by Geert Uytterhoeven

When CONFIG_FORTIFY_SOURCE is not enabled, all fortify tests are skipped. Move this logic from run-time to config-time, to avoid people building and running tests that do not do anything. This basically reverts commit 1a78f8cb5daac774 ("fortify: Allow KUnit test to build without FORTIFY") in v6.9, which was v3 of commit a9dc8d0442294b42 ("fortify: Allow KUnit test to build without FORTIFY") in v6.5, which was quickly reverted in commit 5e2956ee46244ffb ("Revert "fortify: Allow KUnit test to build without FORTIFY""). Signed-off-by: Geert Uytterhoeven <geert(a)linux-m68k.org> --- Let's keep on playing whack-a-mole ;-) --- lib/Kconfig.debug | 1 + lib/tests/fortify_kunit.c | 8 -------- 2 files changed, 1 insertion(+), 8 deletions(-) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 407f2ed7fcb3e94c..ca5afd192c9fbf51 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2912,6 +2912,7 @@ config STACKINIT_KUNIT_TEST config FORTIFY_KUNIT_TEST tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS depends on KUNIT + depends on FORTIFY_SOURCE default KUNIT_ALL_TESTS help Builds unit tests for checking internals of FORTIFY_SOURCE as used diff --git a/lib/tests/fortify_kunit.c b/lib/tests/fortify_kunit.c index 29ffc62a71e3f968..10b0e1b12cdc3ae2 100644 --- a/lib/tests/fortify_kunit.c +++ b/lib/tests/fortify_kunit.c @@ -48,11 +48,6 @@ void fortify_add_kunit_error(int write); #include <linux/string.h> #include <linux/vmalloc.h> -/* Handle being built without CONFIG_FORTIFY_SOURCE */ -#ifndef __compiletime_strlen -# define __compiletime_strlen __builtin_strlen -#endif - static struct kunit_resource read_resource; static struct kunit_resource write_resource; static int fortify_read_overflows; @@ -1071,9 +1066,6 @@ static void fortify_test_kmemdup(struct kunit *test) static int fortify_test_init(struct kunit *test) { - if (!IS_ENABLED(CONFIG_FORTIFY_SOURCE)) - kunit_skip(test, "Not built with CONFIG_FORTIFY_SOURCE=y"); - fortify_read_overflows = 0; kunit_add_named_resource(test, NULL, NULL, &read_resource, "fortify_read_overflows", -- 2.43.0

2 hours, 3 minutes

1
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[PATCH] lib/tests: Make RANDSTRUCT_KUNIT_TEST depend on RANDSTRUCT

by Geert Uytterhoeven

When CONFIG_RANDSTRUCT is not enabled, all randstruct tests are skipped. Move this logic from run-time to config-time, to avoid people building and running tests that do not do anything. Fixes: b370f7eacdcfe1dd ("lib/tests: Add randstruct KUnit test") Signed-off-by: Geert Uytterhoeven <geert(a)linux-m68k.org> --- FTR, after adding "select HAVE_GCC_PLUGINS" to arch/m68k/Kconfig and installing gcc-13-plugin-dev-m68k-linux-gnu, I could enable CONFIG_RANDSTRUCT_FULL and run the tests (all passed!), so probably I should send a patch to select HAVE_GCC_PLUGINS? --- lib/Kconfig.debug | 4 ++-- lib/tests/randstruct_kunit.c | 9 --------- 2 files changed, 2 insertions(+), 11 deletions(-) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index a8b4febad716a4be..407f2ed7fcb3e94c 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2895,10 +2895,10 @@ config OVERFLOW_KUNIT_TEST config RANDSTRUCT_KUNIT_TEST tristate "Test randstruct structure layout randomization at runtime" if !KUNIT_ALL_TESTS depends on KUNIT + depends on RANDSTRUCT default KUNIT_ALL_TESTS help - Builds unit tests for the checking CONFIG_RANDSTRUCT=y, which - randomizes structure layouts. + Builds unit tests for checking structure layout randomization. config STACKINIT_KUNIT_TEST tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS diff --git a/lib/tests/randstruct_kunit.c b/lib/tests/randstruct_kunit.c index f3a2d63c4cfbe7dc..2c95eca76d2411bc 100644 --- a/lib/tests/randstruct_kunit.c +++ b/lib/tests/randstruct_kunit.c @@ -305,14 +305,6 @@ static void randstruct_initializers(struct kunit *test) #undef init_members } -static int randstruct_test_init(struct kunit *test) -{ - if (!IS_ENABLED(CONFIG_RANDSTRUCT)) - kunit_skip(test, "Not built with CONFIG_RANDSTRUCT=y"); - - return 0; -} - static struct kunit_case randstruct_test_cases[] = { KUNIT_CASE(randstruct_layout_same), KUNIT_CASE(randstruct_layout_mixed), @@ -324,7 +316,6 @@ static struct kunit_case randstruct_test_cases[] = { static struct kunit_suite randstruct_test_suite = { .name = "randstruct", - .init = randstruct_test_init, .test_cases = randstruct_test_cases, }; -- 2.43.0

2 hours, 5 minutes

1
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Re: [syzbot] [cgroups?] general protection fault in __cgroup_rstat_lock

by syzbot

syzbot suspects this issue was fixed by commit: commit a97915559f5c5ff1972d678b94fd460c72a3b5f2 Author: JP Kobryn <inwardvessel(a)gmail.com> Date: Fri Apr 4 01:10:48 2025 +0000 cgroup: change rstat function signatures from cgroup-based to css-based bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12ca4c82580000 start commit: 932fc2f19b74 Merge branch 'irq-save-restore' git tree: bpf-next kernel config: https://syzkaller.appspot.com/x/.config?x=50c7a61469ce77e7 dashboard link: https://syzkaller.appspot.com/bug?extid=31eb4d4e7d9bc1fc1312 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=161cdfc0580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12dfc8df980000 If the result looks correct, please mark the issue as fixed by replying with: #syz fix: cgroup: change rstat function signatures from cgroup-based to css-based For information about bisection process see: https://goo.gl/tpsmEJ#bisection

2 hours, 38 minutes

2
1
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[PATCH v11 0/5] rust: replace kernel::str::CStr w/ core::ffi::CStr

by Tamir Duberstein

This picks up from Michal Rostecki's work[0]. Per Michal's guidance I have omitted Co-authored tags, as the end result is quite different. Link: https://lore.kernel.org/rust-for-linux/20240819153656.28807-2-vadorovsky@pr… [0] Closes: https://github.com/Rust-for-Linux/linux/issues/1075 Signed-off-by: Tamir Duberstein <tamird(a)gmail.com> --- Changes in v11: - Use `quote_spanned!` to avoid `use<'a, T>` and generally reduce manual token construction. - Add a commit to simplify `quote_spanned!`. - Drop first commit in favor of https://lore.kernel.org/rust-for-linux/20240906164448.2268368-1-paddymills@…. (Miguel Ojeda) - Correctly handle expressions such as `pr_info!("{a}", a = a = a)`. (Benno Lossin) - Avoid dealing with `}}` escapes, which is not needed. (Benno Lossin) - Revert some unnecessary changes. (Benno Lossin) - Rename `c_str_avoid_literals!` to `str_to_cstr!`. (Benno Lossin & Alice Ryhl). - Link to v10: https://lore.kernel.org/r/20250524-cstr-core-v10-0-6412a94d9d75@gmail.com Changes in v10: - Rebase on cbeaa41dfe26b72639141e87183cb23e00d4b0dd. - Implement Alice's suggestion to use a proc macro to work around orphan rules otherwise preventing `core::ffi::CStr` to be directly printed with `{}`. - Link to v9: https://lore.kernel.org/r/20250317-cstr-core-v9-0-51d6cc522f62@gmail.com Changes in v9: - Rebase on rust-next. - Restore `impl Display for BStr` which exists upstream[1]. - Link: https://doc.rust-lang.org/nightly/std/bstr/struct.ByteStr.html#impl-Display… [1] - Link to v8: https://lore.kernel.org/r/20250203-cstr-core-v8-0-cb3f26e78686@gmail.com Changes in v8: - Move `{from,as}_char_ptr` back to `CStrExt`. This reduces the diff some. - Restore `from_bytes_with_nul_unchecked_mut`, `to_cstring`. - Link to v7: https://lore.kernel.org/r/20250202-cstr-core-v7-0-da1802520438@gmail.com Changes in v7: - Rebased on mainline. - Restore functionality added in commit a321f3ad0a5d ("rust: str: add {make,to}_{upper,lower}case() to CString"). - Used `diff.algorithm patience` to improve diff readability. - Link to v6: https://lore.kernel.org/r/20250202-cstr-core-v6-0-8469cd6d29fd@gmail.com Changes in v6: - Split the work into several commits for ease of review. - Restore `{from,as}_char_ptr` to allow building on ARM (see commit message). - Add `CStrExt` to `kernel::prelude`. (Alice Ryhl) - Remove `CStrExt::from_bytes_with_nul_unchecked_mut` and restore `DerefMut for CString`. (Alice Ryhl) - Rename and hide `kernel::c_str!` to encourage use of C-String literals. - Drop implementation and invocation changes in kunit.rs. (Trevor Gross) - Drop docs on `Display` impl. (Trevor Gross) - Rewrite docs in the style of the standard library. - Restore the `test_cstr_debug` unit tests to demonstrate that the implementation has changed. Changes in v5: - Keep the `test_cstr_display*` unit tests. Changes in v4: - Provide the `CStrExt` trait with `display()` method, which returns a `CStrDisplay` wrapper with `Display` implementation. This addresses the lack of `Display` implementation for `core::ffi::CStr`. - Provide `from_bytes_with_nul_unchecked_mut()` method in `CStrExt`, which might be useful and is going to prevent manual, unsafe casts. - Fix a typo (s/preffered/prefered/). Changes in v3: - Fix the commit message. - Remove redundant braces in `use`, when only one item is imported. Changes in v2: - Do not remove `c_str` macro. While it's preferred to use C-string literals, there are two cases where `c_str` is helpful: - When working with macros, which already return a Rust string literal (e.g. `stringify!`). - When building macros, where we want to take a Rust string literal as an argument (for caller's convenience), but still use it as a C-string internally. - Use Rust literals as arguments in macros (`new_mutex`, `new_condvar`, `new_mutex`). Use the `c_str` macro to convert these literals to C-string literals. - Use `c_str` in kunit.rs for converting the output of `stringify!` to a `CStr`. - Remove `DerefMut` implementation for `CString`. --- Tamir Duberstein (5): rust: macros: reduce collections in `quote!` macro rust: support formatting of foreign types rust: replace `CStr` with `core::ffi::CStr` rust: replace `kernel::c_str!` with C-Strings rust: remove core::ffi::CStr reexport drivers/block/rnull.rs | 4 +- drivers/gpu/drm/drm_panic_qr.rs | 5 +- drivers/gpu/nova-core/driver.rs | 2 +- drivers/gpu/nova-core/firmware.rs | 2 +- drivers/net/phy/ax88796b_rust.rs | 8 +- drivers/net/phy/qt2025.rs | 6 +- rust/kernel/block/mq.rs | 2 +- rust/kernel/device.rs | 9 +- rust/kernel/devres.rs | 2 +- rust/kernel/driver.rs | 4 +- rust/kernel/error.rs | 10 +- rust/kernel/faux.rs | 5 +- rust/kernel/firmware.rs | 16 +- rust/kernel/fmt.rs | 77 ++++++ rust/kernel/kunit.rs | 21 +- rust/kernel/lib.rs | 3 +- rust/kernel/miscdevice.rs | 5 +- rust/kernel/net/phy.rs | 12 +- rust/kernel/of.rs | 5 +- rust/kernel/pci.rs | 2 +- rust/kernel/platform.rs | 6 +- rust/kernel/prelude.rs | 5 +- rust/kernel/print.rs | 4 +- rust/kernel/seq_file.rs | 6 +- rust/kernel/str.rs | 443 ++++++++++------------------------- rust/kernel/sync.rs | 7 +- rust/kernel/sync/condvar.rs | 4 +- rust/kernel/sync/lock.rs | 4 +- rust/kernel/sync/lock/global.rs | 6 +- rust/kernel/sync/poll.rs | 1 + rust/kernel/workqueue.rs | 9 +- rust/macros/fmt.rs | 99 ++++++++ rust/macros/kunit.rs | 10 +- rust/macros/lib.rs | 19 ++ rust/macros/module.rs | 2 +- rust/macros/quote.rs | 111 ++++----- samples/rust/rust_driver_faux.rs | 4 +- samples/rust/rust_driver_pci.rs | 4 +- samples/rust/rust_driver_platform.rs | 4 +- samples/rust/rust_misc_device.rs | 3 +- scripts/rustdoc_test_gen.rs | 6 +- 41 files changed, 485 insertions(+), 472 deletions(-) --- base-commit: 7a17bbc1d952057898cb0739e60665908fbb8c72 change-id: 20250201-cstr-core-d4b9b69120cf Best regards, -- Tamir Duberstein <tamird(a)gmail.com>

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[PATCH net] Revert "kunit: configs: Enable CONFIG_INIT_STACK_ALL_PATTERN in all_tests"

by Jakub Kicinski

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

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[PATCH v2] selftests/ptrace/get_syscall_info: fix for MIPS n32

by Dmitry V. Levin

MIPS n32 is one of two ILP32 architectures supported by the kernel that have 64-bit syscall arguments (another one is x32). When this test passed 32-bit arguments to syscall(), they were sign-extended in libc, PTRACE_GET_SYSCALL_INFO reported these sign-extended 64-bit values, and the test complained about the mismatch. Fix this by passing arguments of the appropriate type to syscall(), which is "unsigned long long" on MIPS n32, and __kernel_ulong_t on other architectures. As a side effect, this also extends the test on all 64-bit architectures by choosing constants that don't fit into 32-bit integers. Signed-off-by: Dmitry V. Levin <ldv(a)strace.io> --- v2: Fixed MIPS #ifdef. .../selftests/ptrace/get_syscall_info.c | 53 +++++++++++-------- 1 file changed, 32 insertions(+), 21 deletions(-) diff --git a/tools/testing/selftests/ptrace/get_syscall_info.c b/tools/testing/selftests/ptrace/get_syscall_info.c index 5bcd1c7b5be6..2970f72d66d3 100644 --- a/tools/testing/selftests/ptrace/get_syscall_info.c +++ b/tools/testing/selftests/ptrace/get_syscall_info.c @@ -11,8 +11,19 @@ #include <err.h> #include <signal.h> #include <asm/unistd.h> +#include <linux/types.h> #include "linux/ptrace.h" +#if defined(_MIPS_SIM) && _MIPS_SIM == _MIPS_SIM_NABI32 +/* + * MIPS N32 is the only architecture where __kernel_ulong_t + * does not match the bitness of syscall arguments. + */ +typedef unsigned long long kernel_ulong_t; +#else +typedef __kernel_ulong_t kernel_ulong_t; +#endif + static int kill_tracee(pid_t pid) { @@ -42,37 +53,37 @@ sys_ptrace(int request, pid_t pid, unsigned long addr, unsigned long data) TEST(get_syscall_info) { - static const unsigned long args[][7] = { + const kernel_ulong_t args[][7] = { /* a sequence of architecture-agnostic syscalls */ { __NR_chdir, - (unsigned long) "", - 0xbad1fed1, - 0xbad2fed2, - 0xbad3fed3, - 0xbad4fed4, - 0xbad5fed5 + (uintptr_t) "", + (kernel_ulong_t) 0xdad1bef1bad1fed1ULL, + (kernel_ulong_t) 0xdad2bef2bad2fed2ULL, + (kernel_ulong_t) 0xdad3bef3bad3fed3ULL, + (kernel_ulong_t) 0xdad4bef4bad4fed4ULL, + (kernel_ulong_t) 0xdad5bef5bad5fed5ULL }, { __NR_gettid, - 0xcaf0bea0, - 0xcaf1bea1, - 0xcaf2bea2, - 0xcaf3bea3, - 0xcaf4bea4, - 0xcaf5bea5 + (kernel_ulong_t) 0xdad0bef0caf0bea0ULL, + (kernel_ulong_t) 0xdad1bef1caf1bea1ULL, + (kernel_ulong_t) 0xdad2bef2caf2bea2ULL, + (kernel_ulong_t) 0xdad3bef3caf3bea3ULL, + (kernel_ulong_t) 0xdad4bef4caf4bea4ULL, + (kernel_ulong_t) 0xdad5bef5caf5bea5ULL }, { __NR_exit_group, 0, - 0xfac1c0d1, - 0xfac2c0d2, - 0xfac3c0d3, - 0xfac4c0d4, - 0xfac5c0d5 + (kernel_ulong_t) 0xdad1bef1fac1c0d1ULL, + (kernel_ulong_t) 0xdad2bef2fac2c0d2ULL, + (kernel_ulong_t) 0xdad3bef3fac3c0d3ULL, + (kernel_ulong_t) 0xdad4bef4fac4c0d4ULL, + (kernel_ulong_t) 0xdad5bef5fac5c0d5ULL } }; - const unsigned long *exp_args; + const kernel_ulong_t *exp_args; pid_t pid = fork(); @@ -154,7 +165,7 @@ TEST(get_syscall_info) } ASSERT_LT(0, (rc = sys_ptrace(PTRACE_GET_SYSCALL_INFO, pid, size, - (unsigned long) &info))) { + (uintptr_t) &info))) { LOG_KILL_TRACEE("PTRACE_GET_SYSCALL_INFO: %m"); } ASSERT_EQ(expected_none_size, rc) { @@ -177,7 +188,7 @@ TEST(get_syscall_info) case SIGTRAP | 0x80: ASSERT_LT(0, (rc = sys_ptrace(PTRACE_GET_SYSCALL_INFO, pid, size, - (unsigned long) &info))) { + (uintptr_t) &info))) { LOG_KILL_TRACEE("PTRACE_GET_SYSCALL_INFO: %m"); } switch (ptrace_stop) { -- ldv

4 hours, 55 minutes

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[PATCH v5 0/5] kunit: Add support for suppressing warning backtraces

by Alessandro Carminati

Some unit tests intentionally trigger warning backtraces by passing bad parameters to kernel API functions. Such unit tests typically check the return value from such calls, not the existence of the warning backtrace. Such intentionally generated warning backtraces are neither desirable nor useful for a number of reasons: - They can result in overlooked real problems. - A warning that suddenly starts to show up in unit tests needs to be investigated and has to be marked to be ignored, for example by adjusting filter scripts. Such filters are ad hoc because there is no real standard format for warnings. On top of that, such filter scripts would require constant maintenance. One option to address the problem would be to add messages such as "expected warning backtraces start/end here" to the kernel log. However, that would again require filter scripts, might result in missing real problematic warning backtraces triggered while the test is running, and the irrelevant backtrace(s) would still clog the kernel log. Solve the problem by providing a means to identify and suppress specific warning backtraces while executing test code. Support suppressing multiple backtraces while at the same time limiting changes to generic code to the absolute minimum. Overview: Patch#1 Introduces the suppression infrastructure. Patch#2 Mitigate the impact at WARN*() sites. Patch#3 Adds selftests to validate the functionality. Patch#4 Demonstrates real-world usage in the DRM subsystem. Patch#5 Documents the new API and usage guidelines. Design Notes: The objective is to suppress unwanted WARN*() generated messages. Although most major architectures share common bug handling via `lib/bug.c` and `report_bug()`, some minor or legacy architectures still rely on their own platform-specific handling. This divergence must be considered in any such feature. Additionally, a key challenge in implementing this feature is the fragmentation of `WARN*()` messages emission: specific part in the macro, common with BUG*() part in the exception handler. As a result, any intervention to suppress the message must occur before the illegal instruction. Lessons from the Previous Attempt In earlier iterations, suppression logic was added inside the `__report_bug()` function to intercept WARN*() messages not producing messages in the macro. To implement the check in the check in the bug handler code, two strategies were considered: * Strategy #1: Use `kallsyms` to infer the originating functionid, namely a pointer to the function. Since in any case, the user interface relies on function names, they must be translated in addresses at suppression- time or at check-time. Assuming to translate at suppression-time, the `kallsyms` subsystem needs to be used to determine the symbol address from the name, and again to produce the functionid from `bugaddr`. This approach proved unreliable due to compiler-induced transformations such as inlining, cloning, and code fragmentation. Attempts to preventing them is also unconvenient because several `WARN()` sites are in functions intentionally declared as `__always_inline`. * Strategy #2: Store function name `__func__` in `struct bug_entry` in the `__bug_table`. This implementation was used in the previous version. However, `__func__` is a compiler-generated symbol, which complicates relocation and linking in position-independent code. Workarounds such as storing offsets from `.rodata` or embedding string literals directly into the table would have significantly either increased complexity or increase the __bug_table size. Additionally, architectures not using the unified `BUG()` path would still require ad-hoc handling. Because current WARN*() message production strategy, a few WARN*() macros still need a check to suppress the part of the message produced in the macro itself. Current Proposal: Check Directly in the `WARN()` Macros. This avoids the need for function symbol resolution or ELF section modification. Suppression is implemented directly in the `WARN*()` macros. A helper function, `__kunit_is_suppressed_warning()`, is used to determine whether suppression applies. It is marked as `noinstr`, since some `WARN*()` sites reside in non-instrumentable sections. As it uses `strcmp`, a `noinstr` version of `strcmp` was introduced. The implementation is deliberately simple and avoids architecture-specific optimizations to preserve portability. Since this mechanism compares function names and is intended for test usage only, performance is not a primary concern. This series is based on the RFC patch and subsequent discussion at https://patchwork.kernel.org/project/linux-kselftest/patch/02546e59-1afe-4b… and offers a more comprehensive solution of the problem discussed there. Changes since RFC: - Introduced CONFIG_KUNIT_SUPPRESS_BACKTRACE - Minor cleanups and bug fixes - Added support for all affected architectures - Added support for counting suppressed warnings - Added unit tests using those counters - Added patch to suppress warning backtraces in dev_addr_lists tests Changes since v1: - Rebased to v6.9-rc1 - Added Tested-by:, Acked-by:, and Reviewed-by: tags [I retained those tags since there have been no functional changes] - Introduced KUNIT_SUPPRESS_BACKTRACE configuration option, enabled by default. Changes since v2: - Rebased to v6.9-rc2 - Added comments to drm warning suppression explaining why it is needed. - Added patch to move conditional code in arch/sh/include/asm/bug.h to avoid kerneldoc warning - Added architecture maintainers to Cc: for architecture specific patches - No functional changes Changes since v3: - Rebased to v6.14-rc6 - Dropped net: "kunit: Suppress lock warning noise at end of dev_addr_lists tests" since 3db3b62955cd6d73afde05a17d7e8e106695c3b9 - Added __kunit_ and KUNIT_ prefixes. - Tested on interessed architectures. Changes since v4: - Rebased to v6.15-rc7 - Dropped all code in __report_bug() - Moved all checks in WARN*() macros. - Dropped all architecture specific code. - Made __kunit_is_suppressed_warning nice to noinstr functions. Alessandro Carminati (2): bug/kunit: Core support for suppressing warning backtraces bug/kunit: Suppressing warning backtraces reduced impact on WARN*() sites Guenter Roeck (3): Add unit tests to verify that warning backtrace suppression works. drm: Suppress intentional warning backtraces in scaling unit tests kunit: Add documentation for warning backtrace suppression API Documentation/dev-tools/kunit/usage.rst | 30 ++++++- drivers/gpu/drm/tests/drm_rect_test.c | 16 ++++ include/asm-generic/bug.h | 48 +++++++---- include/kunit/bug.h | 62 ++++++++++++++ include/kunit/test.h | 1 + lib/kunit/Kconfig | 9 ++ lib/kunit/Makefile | 9 +- lib/kunit/backtrace-suppression-test.c | 105 ++++++++++++++++++++++++ lib/kunit/bug.c | 54 ++++++++++++ 9 files changed, 316 insertions(+), 18 deletions(-) create mode 100644 include/kunit/bug.h create mode 100644 lib/kunit/backtrace-suppression-test.c create mode 100644 lib/kunit/bug.c -- 2.34.1

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