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2024-12-06selftests/bpf: Consolidate kernel modules into common directoryToke Høiland-Jørgensen
The selftests build four kernel modules which use copy-pasted Makefile targets. This is a bit messy, and doesn't scale so well when we add more modules, so let's consolidate these rules into a single rule generated for each module name, and move the module sources into a single directory. To avoid parallel builds of the different modules stepping on each other's toes during the 'modpost' phase of the Kbuild 'make modules', the module files should really be a grouped target. However, make only added explicit support for grouped targets in version 4.3, which is newer than the minimum version supported by the kernel. However, make implicitly treats pattern matching rules with multiple targets as a grouped target, so we can work around this by turning the rule into a pattern matching target. We do this by replacing '.ko' with '%ko' in the targets with subst(). Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Viktor Malik <vmalik@redhat.com> Link: https://lore.kernel.org/bpf/20241204-bpf-selftests-mod-compile-v5-1-b96231134a49@redhat.com
2023-05-16selftests/bpf: Move kfunc exports to bpf_testmod/bpf_testmod_kfunc.hJiri Olsa
Move all kfunc exports into separate bpf_testmod_kfunc.h header file and include it in tests that need it. We will move all test kfuncs into bpf_testmod in following change, so it's convenient to have declarations in single place. The bpf_testmod_kfunc.h is included by both bpf_testmod and bpf programs that use test kfuncs. As suggested by David, the bpf_testmod_kfunc.h includes vmlinux.h and bpf/bpf_helpers.h for bpf programs build, so the declarations have proper __ksym attribute and we can resolve all the structs. Note in kfunc_call_test_subprog.c we can no longer use the sk_state define from bpf_tcp_helpers.h (because it clashed with vmlinux.h) and we need to address __sk_common.skc_state field directly. Acked-by: David Vernet <void@manifault.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20230515133756.1658301-3-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-18selftests/bpf: Add test for race in btf_try_get_moduleKumar Kartikeya Dwivedi
This adds a complete test case to ensure we never take references to modules not in MODULE_STATE_LIVE, which can lead to UAF, and it also ensures we never access btf->kfunc_set_tab in an inconsistent state. The test uses userfaultfd to artificially widen the race. When run on an unpatched kernel, it leads to the following splat: [root@(none) bpf]# ./test_progs -t bpf_mod_race/ksym [ 55.498171] BUG: unable to handle page fault for address: fffffbfff802548b [ 55.499206] #PF: supervisor read access in kernel mode [ 55.499855] #PF: error_code(0x0000) - not-present page [ 55.500555] PGD a4fa9067 P4D a4fa9067 PUD a4fa5067 PMD 1b44067 PTE 0 [ 55.501499] Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI [ 55.502195] CPU: 0 PID: 83 Comm: kworker/0:2 Tainted: G OE 5.16.0-rc4+ #151 [ 55.503388] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ArchLinux 1.15.0-1 04/01/2014 [ 55.504777] Workqueue: events bpf_prog_free_deferred [ 55.505563] RIP: 0010:kasan_check_range+0x184/0x1d0 [ 55.509140] RSP: 0018:ffff88800560fcf0 EFLAGS: 00010282 [ 55.509977] RAX: fffffbfff802548b RBX: fffffbfff802548c RCX: ffffffff9337b6ba [ 55.511096] RDX: fffffbfff802548c RSI: 0000000000000004 RDI: ffffffffc012a458 [ 55.512143] RBP: fffffbfff802548b R08: 0000000000000001 R09: ffffffffc012a45b [ 55.513228] R10: fffffbfff802548b R11: 0000000000000001 R12: ffff888001b5f598 [ 55.514332] R13: ffff888004f49ac8 R14: 0000000000000000 R15: ffff888092449400 [ 55.515418] FS: 0000000000000000(0000) GS:ffff888092400000(0000) knlGS:0000000000000000 [ 55.516705] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 55.517560] CR2: fffffbfff802548b CR3: 0000000007c10006 CR4: 0000000000770ef0 [ 55.518672] PKRU: 55555554 [ 55.519022] Call Trace: [ 55.519483] <TASK> [ 55.519884] module_put.part.0+0x2a/0x180 [ 55.520642] bpf_prog_free_deferred+0x129/0x2e0 [ 55.521478] process_one_work+0x4fa/0x9e0 [ 55.522122] ? pwq_dec_nr_in_flight+0x100/0x100 [ 55.522878] ? rwlock_bug.part.0+0x60/0x60 [ 55.523551] worker_thread+0x2eb/0x700 [ 55.524176] ? __kthread_parkme+0xd8/0xf0 [ 55.524853] ? process_one_work+0x9e0/0x9e0 [ 55.525544] kthread+0x23a/0x270 [ 55.526088] ? set_kthread_struct+0x80/0x80 [ 55.526798] ret_from_fork+0x1f/0x30 [ 55.527413] </TASK> [ 55.527813] Modules linked in: bpf_testmod(OE) [last unloaded: bpf_testmod] [ 55.530846] CR2: fffffbfff802548b [ 55.531341] ---[ end trace 1af41803c054ad6d ]--- [ 55.532136] RIP: 0010:kasan_check_range+0x184/0x1d0 [ 55.535887] RSP: 0018:ffff88800560fcf0 EFLAGS: 00010282 [ 55.536711] RAX: fffffbfff802548b RBX: fffffbfff802548c RCX: ffffffff9337b6ba [ 55.537821] RDX: fffffbfff802548c RSI: 0000000000000004 RDI: ffffffffc012a458 [ 55.538899] RBP: fffffbfff802548b R08: 0000000000000001 R09: ffffffffc012a45b [ 55.539928] R10: fffffbfff802548b R11: 0000000000000001 R12: ffff888001b5f598 [ 55.541021] R13: ffff888004f49ac8 R14: 0000000000000000 R15: ffff888092449400 [ 55.542108] FS: 0000000000000000(0000) GS:ffff888092400000(0000) knlGS:0000000000000000 [ 55.543260]CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 55.544136] CR2: fffffbfff802548b CR3: 0000000007c10006 CR4: 0000000000770ef0 [ 55.545317] PKRU: 55555554 [ 55.545671] note: kworker/0:2[83] exited with preempt_count 1 Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20220114163953.1455836-11-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>