- 29 Jul, 2024 40 commits
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Tony Ambardar authored
The addition of general support for unprivileged tests in test_loader.c breaks building test_verifier on non-glibc (e.g. musl) systems, due to the inclusion of glibc extension '<error.h>' in 'unpriv_helpers.c'. However, the header is actually not needed, so remove it to restore building. Similarly for sk_lookup.c and flow_dissector.c, error.h is not necessary and causes problems, so drop them. Fixes: 1d56ade0 ("selftests/bpf: Unprivileged tests for test_loader.c") Fixes: 0ab5539f ("selftests/bpf: Tests for BPF_SK_LOOKUP attach point") Fixes: 0905beec ("selftests/bpf: run flow dissector tests in skb-less mode") Signed-off-by:
Tony Ambardar <tony.ambardar@gmail.com> Signed-off-by:
Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/5664367edf5fea4f3f4b4aec3b182bcfc6edff9c.1721713597.git.tony.ambardar@gmail.com
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Tony Ambardar authored
Existing code calls getsockname() with a 'struct sockaddr_in6 *' argument where a 'struct sockaddr *' argument is declared, yielding compile errors when building for mips64el/musl-libc: bpf_iter_setsockopt.c: In function 'get_local_port': bpf_iter_setsockopt.c:98:30: error: passing argument 2 of 'getsockname' from incompatible pointer type [-Werror=incompatible-pointer-types] 98 | if (!getsockname(fd, &addr, &addrlen)) | ^~~~~ | | | struct sockaddr_in6 * In file included from .../netinet/in.h:10, from .../arpa/inet.h:9, from ./test_progs.h:17, from bpf_iter_setsockopt.c:5: .../sys/socket.h:391:23: note: expected 'struct sockaddr * restrict' but argument is of type 'struct sockaddr_in6 *' 391 | int getsockname (int, struct sockaddr *__restrict, socklen_t *__restrict); | ^ cc1: all warnings being treated as errors This compiled under glibc only because the argument is declared to be a "funky" transparent union which includes both types above. Explicitly cast the argument to allow compiling for both musl and glibc. Fixes: eed92afd ("bpf: selftest: Test batching and bpf_(get|set)sockopt in bpf tcp iter") Signed-off-by:Geliang Tang <geliang@kernel.org> Link: https://lore.kernel.org/bpf/f41def0f17b27a23b1709080e4e3f37f4cc11ca9.1721713597.git.tony.ambardar@gmail.com
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Tony Ambardar authored
Cast 'rlim_t' argument to match expected type of printf() format and avoid compile errors seen building for mips64el/musl-libc: In file included from map_tests/sk_storage_map.c:20: map_tests/sk_storage_map.c: In function 'test_sk_storage_map_stress_free': map_tests/sk_storage_map.c:414:56: error: format '%lu' expects argument of type 'long unsigned int', but argument 2 has type 'rlim_t' {aka 'long long unsigned int'} [-Werror=format=] 414 | CHECK(err, "setrlimit(RLIMIT_NOFILE)", "rlim_new:%lu errno:%d", | ^~~~~~~~~~~~~~~~~~~~~~~ 415 | rlim_new.rlim_cur, errno); | ~~~~~~~~~~~~~~~~~ | | | rlim_t {aka long long unsigned int} ./test_maps.h:12:24: note: in definition of macro 'CHECK' 12 | printf(format); \ | ^~~~~~ map_tests/sk_storage_map.c:414:68: note: format string is defined here 414 | CHECK(err, "setrlimit(RLIMIT_NOFILE)", "rlim_new:%lu errno:%d", | ~~^ | | | long unsigned int | %llu cc1: all warnings being treated as errors Fixes: 51a0e301 ("bpf: Add BPF_MAP_TYPE_SK_STORAGE test to test_maps") Signed-off-by: -
Tony Ambardar authored
Use pid_t rather than __pid_t when allocating memory for 'worker_pids' in 'struct test_env', as this is its declared type and also avoids compile errors seen building against musl libc on mipsel64: test_progs.c:1738:49: error: '__pid_t' undeclared (first use in this function); did you mean 'pid_t'? 1738 | env.worker_pids = calloc(sizeof(__pid_t), env.workers); | ^~~~~~~ | pid_t test_progs.c:1738:49: note: each undeclared identifier is reported only once for each function it appears in Fixes: 91b2c0af ("selftests/bpf: Add parallelism to test_progs") Signed-off-by: -
Ihor Solodrai authored
%.test.o should depend on %.test.d order-only to avoid unnecessary recompilations due to compiler dumping .d and .o files in random order. Signed-off-by:
Ihor Solodrai <ihor.solodrai@pm.me> Signed-off-by:
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Alexei Starovoitov authored
Eduard Zingerman says: ==================== no_caller_saved_registers attribute for helper calls This patch-set seeks to allow using no_caller_saved_registers gcc/clang attribute with some BPF helper functions (and kfuncs in the future). As documented in [1], this attribute means that function scratches only some of the caller saved registers defined by ABI. For BPF the set of such registers could be defined as follows: - R0 is scratched only if function is non-void; - R1-R5 are scratched only if corresponding parameter type is defined in the function prototype. The goal of the patch-set is to implement no_caller_saved_registers (nocsr for short) in a backwards compatible manner: - for kernels that support the feature, gain some performance boost from better register allocation; - for kernels that don't support the feature, allow programs execution with minor performance losses. To achieve this, use a scheme suggested by Alexei Starovoitov: - for nocsr calls clang allocates registers as-if relevant r0-r5 registers are not scratched by the call; - as a post-processing step, clang visits each nocsr call and adds spill/fill for every live r0-r5; - stack offsets used for spills/fills are allocated as lowest stack offsets in whole function and are not used for any other purpose; - when kernel loads a program, it looks for such patterns (nocsr function surrounded by spills/fills) and checks if spill/fill stack offsets are used exclusively in nocsr patterns; - if so, and if current JIT inlines the call to the nocsr function (e.g. a helper call), kernel removes unnecessary spill/fill pairs; - when old kernel loads a program, presence of spill/fill pairs keeps BPF program valid, albeit slightly less efficient. Corresponding clang/llvm changes are available in [2]. The patch-set uses bpf_get_smp_processor_id() function as a canary, making it the first helper with nocsr attribute. For example, consider the following program: #define __no_csr __attribute__((no_caller_saved_registers)) #define SEC(name) __attribute__((section(name), used)) #define bpf_printk(fmt, ...) bpf_trace_printk((fmt), sizeof(fmt), __VA_ARGS__) typedef unsigned int __u32; static long (* const bpf_trace_printk)(const char *fmt, __u32 fmt_size, ...) = (void *) 6; static __u32 (*const bpf_get_smp_processor_id)(void) __no_csr = (void *)8; SEC("raw_tp") int test(void *ctx) { __u32 task = bpf_get_smp_processor_id(); bpf_printk("ctx=%p, smp=%d", ctx, task); return 0; } char _license[] SEC("license") = "GPL"; Compiled (using [2]) as follows: $ clang --target=bpf -O2 -g -c -o nocsr.bpf.o nocsr.bpf.c $ llvm-objdump --no-show-raw-insn -Sd nocsr.bpf.o ... 3rd parameter for printk call removable spill/fill pair .--- 0: r3 = r1 | ; | __u32 task = bpf_get_smp_processor_id(); | | 1: *(u64 *)(r10 - 0x8) = r3 <----------| | 2: call 0x8 | | 3: r3 = *(u64 *)(r10 - 0x8) <----------' ; | bpf_printk("ctx=%p, smp=%d", ctx, task); | 4: r1 = 0x0 ll | 6: r2 = 0xf | 7: r4 = r0 '--> 8: call 0x6 ; return 0; 9: r0 = 0x0 10: exit Here is how the program looks after verifier processing: # bpftool prog load ./nocsr.bpf.o /sys/fs/bpf/nocsr-test # bpftool prog dump xlated pinned /sys/fs/bpf/nocsr-test int test(void * ctx): 0: (bf) r3 = r1 <--- 3rd printk parameter ; __u32 task = bpf_get_smp_processor_id(); 1: (b4) w0 = 197324 <--. inlined helper call, 2: (bf) r0 = &(void __percpu *)(r0) <--- spill/fill 3: (61) r0 = *(u32 *)(r0 +0) <--' pair removed ; bpf_printk("ctx=%p, smp=%d", ctx, task); 4: (18) r1 = map[id:5][0]+0 6: (b7) r2 = 15 7: (bf) r4 = r0 8: (85) call bpf_trace_printk#-125920 ; return 0; 9: (b7) r0 = 0 10: (95) exit [1] https://clang.llvm.org/docs/AttributeReference.html#no-caller-saved-registers [2] https://github.com/eddyz87/llvm-project/tree/bpf-no-caller-saved-registers Change list: - v3 -> v4: - When nocsr spills/fills are removed in the subprogram, allow these spills/fills to reside in [-MAX_BPF_STACK-48..MAX_BPF_STACK) range (suggested by Alexei); - Dropped patches with special handling for bpf_probe_read_kernel() (requested by Alexei); - Reset aux .nocsr_pattern and .nocsr_spills_num fields in check_nocsr_stack_contract() (requested by Andrii). Andrii, I have not added an additional flag to struct bpf_subprog_info, it currently does not have holes and I really don't like adding a bool field there just as an alternative indicator that nocsr is disabled. Indicator at the moment: - nocsr_stack_off >= S16_MIN means that nocsr rewrite is enabled; - nocsr_stack_off == S16_MIN means that nocsr rewrite is disabled. - v2 -> v3: - As suggested by Andrii, 'nocsr_stack_off' is no longer checked at rewrite time, instead mark_nocsr_patterns() now does two passes over BPF program: - on a first pass it computes the lowest stack spill offset for the subprogram; - on a second pass this offset is used to recognize nocsr pattern. - As suggested by Alexei, a new mechanic is added to work around a situation mentioned by Andrii, when more helper functions are marked as nocsr at compile time than current kernel supports: - all {spill*,helper call,fill*} patterns are now marked as insn_aux_data[*].nocsr_pattern, thus relaxing failure condition for check_nocsr_stack_contract(); - spill/fill pairs are not removed for patterns where helper can't be inlined; - see mark_nocsr_pattern_for_call() for details an example. - As suggested by Alexei, subprogram stack depth is now adjusted if all spill/fill pairs could be removed. This adjustment has to take place before optimize_bpf_loop(), hence the rewrite is moved from do_misc_fixups() to remove_nocsr_spills_fills() (again). - As suggested by Andrii, special measures are taken to work around bpf_probe_read_kernel() access to BPF stack, see patches 11, 12. Patch #11 is very simplistic, a more comprehensive solution would be to change the type of the third parameter of the bpf_probe_read_kernel() from ARG_ANYTHING to something else and not only check nocsr contract, but also propagate stack slot liveness information. However, such change would require update in struct bpf_call_arg_meta processing, which currently implies that every memory parameter is followed by a size parameter. I can work on these changes, please comment. - Stylistic changes suggested by Andrii. - Added acks from Andrii. - Dropped RFC tag. - v1 -> v2: - assume that functions inlined by either jit or verifier conform to no_caller_saved_registers contract (Andrii, Puranjay); - allow nocsr rewrite for bpf_get_smp_processor_id() on arm64 and riscv64 architectures (Puranjay); - __arch_{x86_64,arm64,riscv64} macro for test_loader; - moved remove_nocsr_spills_fills() inside do_misc_fixups() (Andrii); - moved nocsr pattern detection from check_cfg() to a separate pass (Andrii); - various stylistic/correctness changes according to Andrii's comments. Revisions: - v1 https://lore.kernel.org/bpf/20240629094733.3863850-1-eddyz87@gmail.com/ - v2 https://lore.kernel.org/bpf/20240704102402.1644916-1-eddyz87@gmail.com/ - v3 https://lore.kernel.org/bpf/20240715230201.3901423-1-eddyz87@gmail.com/ ==================== Link: https://lore.kernel.org/r/20240722233844.1406874-1-eddyz87@gmail.comSigned-off-by:Alexei Starovoitov <ast@kernel.org> Signed-off-by:
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Eduard Zingerman authored
Tests for no_caller_saved_registers processing logic (see verifier.c:match_and_mark_nocsr_pattern()): - a canary positive test case; - a canary test case for arm64 and riscv64; - various tests with broken patterns; - tests with read/write fixed/varying stack access that violate nocsr stack access contract; - tests with multiple subprograms; - tests using nocsr in combination with may_goto/bpf_loop, as all of these features affect stack depth; - tests for nocsr stack spills below max stack depth. Signed-off-by:
Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20240722233844.1406874-11-eddyz87@gmail.comSigned-off-by:
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Eduard Zingerman authored
Add annotations __arch_x86_64, __arch_arm64, __arch_riscv64 to specify on which architecture the test case should be tested. Several __arch_* annotations could be specified at once. When test case is not run on current arch it is marked as skipped. For example, the following would be tested only on arm64 and riscv64: SEC("raw_tp") __arch_arm64 __arch_riscv64 __xlated("1: *(u64 *)(r10 - 16) = r1") __xlated("2: call") __xlated("3: r1 = *(u64 *)(r10 - 16);") __success __naked void canary_arm64_riscv64(void) { asm volatile ( "r1 = 1;" "*(u64 *)(r10 - 16) = r1;" "call %[bpf_get_smp_processor_id];" "r1 = *(u64 *)(r10 - 16);" "exit;" : : __imm(bpf_get_smp_processor_id) : __clobber_all); } On x86 it would be skipped: #467/2 verifier_nocsr/canary_arm64_riscv64:SKIP Acked-by: -
Eduard Zingerman authored
Add a macro __xlated("...") for use with test_loader tests. When such annotations are present for the test case: - bpf_prog_get_info_by_fd() is used to get BPF program after all rewrites are applied by verifier. - the program is disassembled and patterns specified in __xlated are searched for in the disassembly text. __xlated matching follows the same mechanics as __msg: each subsequent pattern is matched from the point where previous pattern ended. This allows to write tests like below, where the goal is to verify the behavior of one of the of the transformations applied by verifier: SEC("raw_tp") __xlated("1: w0 = ") __xlated("2: r0 = &(void __percpu *)(r0)") __xlated("3: r0 = *(u32 *)(r0 +0)") __xlated("4: exit") __success __naked void simple(void) { asm volatile ( "call %[bpf_get_smp_processor_id];" "exit;" : : __imm(bpf_get_smp_processor_id) : __clobber_all); } Acked-by: -
Eduard Zingerman authored
Non-functional change: use a separate data structure to represented expected messages in test_loader. This would allow to use the same functionality for expected set of disassembled instructions in the follow-up commit. Acked-by:
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Eduard Zingerman authored
The call stack for validate_case() function looks as follows: - test_loader__run_subtests() - process_subtest() - run_subtest() - prepare_case(), which does 'tester->next_match_pos = 0'; - validate_case(), which increments tester->next_match_pos. Hence, each subtest is run with next_match_pos freshly set to zero. Meaning that there is no need to persist this variable in the struct test_loader, use local variable instead. Acked-by: -
Eduard Zingerman authored
Adjust disasm_helpers.c:disasm_insn() to account for the following part of the verifier.c:jit_subprogs: for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) { /* ... */ if (!bpf_pseudo_call(insn)) continue; insn->off = env->insn_aux_data[i].call_imm; subprog = find_subprog(env, i + insn->off + 1); insn->imm = subprog; } Where verifier moves offset of the subprogram to the insn->off field. Signed-off-by: -
Yonghong Song authored
Add a few reg_bounds selftests to test 32/16/8-bit ldsx and subreg comparison. Without the previous patch, all added tests will fail. Acked-by:
Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20240723162940.2732171-1-yonghong.song@linux.devSigned-off-by:
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Eduard Zingerman authored
struct bpf_insn *disasm_insn(struct bpf_insn *insn, char *buf, size_t buf_sz); Disassembles instruction 'insn' to a text buffer 'buf'. Removes insn->code hex prefix added by kernel disassembly routine. Returns a pointer to the next instruction (increments insn by either 1 or 2). Acked-by:
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Yonghong Song authored
With latest llvm19, the selftest iters/iter_arr_with_actual_elem_count failed with -mcpu=v4. The following are the details: 0: R1=ctx() R10=fp0 ; int iter_arr_with_actual_elem_count(const void *ctx) @ iters.c:1420 0: (b4) w7 = 0 ; R7_w=0 ; int i, n = loop_data.n, sum = 0; @ iters.c:1422 1: (18) r1 = 0xffffc90000191478 ; R1_w=map_value(map=iters.bss,ks=4,vs=1280,off=1144) 3: (61) r6 = *(u32 *)(r1 +128) ; R1_w=map_value(map=iters.bss,ks=4,vs=1280,off=1144) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) ; if (n > ARRAY_SIZE(loop_data.data)) @ iters.c:1424 4: (26) if w6 > 0x20 goto pc+27 ; R6_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f)) 5: (bf) r8 = r10 ; R8_w=fp0 R10=fp0 6: (07) r8 += -8 ; R8_w=fp-8 ; bpf_for(i, 0, n) { @ iters.c:1427 7: (bf) r1 = r8 ; R1_w=fp-8 R8_w=fp-8 8: (b4) w2 = 0 ; R2_w=0 9: (bc) w3 = w6 ; R3_w=scalar(id=1,smin=smin32=0,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f)) R6_w=scalar(id=1,smin=smin32=0,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f)) 10: (85) call bpf_iter_num_new#45179 ; R0=scalar() fp-8=iter_num(ref_id=2,state=active,depth=0) refs=2 11: (bf) r1 = r8 ; R1=fp-8 R8=fp-8 refs=2 12: (85) call bpf_iter_num_next#45181 13: R0=rdonly_mem(id=3,ref_obj_id=2,sz=4) R6=scalar(id=1,smin=smin32=0,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f)) R7=0 R8=fp-8 R10=fp0 fp-8=iter_num(ref_id=2,state=active,depth=1) refs=2 ; bpf_for(i, 0, n) { @ iters.c:1427 13: (15) if r0 == 0x0 goto pc+2 ; R0=rdonly_mem(id=3,ref_obj_id=2,sz=4) refs=2 14: (81) r1 = *(s32 *)(r0 +0) ; R0=rdonly_mem(id=3,ref_obj_id=2,sz=4) R1_w=scalar(smin=0xffffffff80000000,smax=0x7fffffff) refs=2 15: (ae) if w1 < w6 goto pc+4 20: R0=rdonly_mem(id=3,ref_obj_id=2,sz=4) R1=scalar(smin=0xffffffff80000000,smax=smax32=umax32=31,umax=0xffffffff0000001f,smin32=0,var_off=(0x0; 0xffffffff0000001f)) R6=scalar(id=1,smin=umin=smin32=umin32=1,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f)) R7=0 R8=fp-8 R10=fp0 fp-8=iter_num(ref_id=2,state=active,depth=1) refs=2 ; sum += loop_data.data[i]; @ iters.c:1429 20: (67) r1 <<= 2 ; R1_w=scalar(smax=0x7ffffffc0000007c,umax=0xfffffffc0000007c,smin32=0,smax32=umax32=124,var_off=(0x0; 0xfffffffc0000007c)) refs=2 21: (18) r2 = 0xffffc90000191478 ; R2_w=map_value(map=iters.bss,ks=4,vs=1280,off=1144) refs=2 23: (0f) r2 += r1 math between map_value pointer and register with unbounded min value is not allowed The source code: int iter_arr_with_actual_elem_count(const void *ctx) { int i, n = loop_data.n, sum = 0; if (n > ARRAY_SIZE(loop_data.data)) return 0; bpf_for(i, 0, n) { /* no rechecking of i against ARRAY_SIZE(loop_data.n) */ sum += loop_data.data[i]; } return sum; } The insn #14 is a sign-extenstion load which is related to 'int i'. The insn #15 did a subreg comparision. Note that smin=0xffffffff80000000 and this caused later insn #23 failed verification due to unbounded min value. Actually insn #15 R1 smin range can be better. Before insn #15, we have R1_w=scalar(smin=0xffffffff80000000,smax=0x7fffffff) With the above range, we know for R1, upper 32bit can only be 0xffffffff or 0. Otherwise, the value range for R1 could be beyond [smin=0xffffffff80000000,smax=0x7fffffff]. After insn #15, for the true patch, we know smin32=0 and smax32=32. With the upper 32bit 0xffffffff, then the corresponding value is [0xffffffff00000000, 0xffffffff00000020]. The range is obviously beyond the original range [smin=0xffffffff80000000,smax=0x7fffffff] and the range is not possible. So the upper 32bit must be 0, which implies smin = smin32 and smax = smax32. This patch fixed the issue by adding additional register deduction after 32-bit compare insn. If the signed 32-bit register range is non-negative then 64-bit smin is in range of [S32_MIN, S32_MAX], then the actual 64-bit smin/smax should be the same as 32-bit smin32/smax32. With this patch, iters/iter_arr_with_actual_elem_count succeeded with better register range: from 15 to 20: R0=rdonly_mem(id=7,ref_obj_id=2,sz=4) R1_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=31,var_off=(0x0; 0x1f)) R6=scalar(id=1,smin=umin=smin32=umin32=1,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f)) R7=scalar(id=9,smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R8=scalar(id=9,smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R10=fp0 fp-8=iter_num(ref_id=2,state=active,depth=3) refs=2 Acked-by:Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by:
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Eduard Zingerman authored
The function bpf_get_smp_processor_id() is processed in a different way, depending on the arch: - on x86 verifier replaces call to bpf_get_smp_processor_id() with a sequence of instructions that modify only r0; - on riscv64 jit replaces call to bpf_get_smp_processor_id() with a sequence of instructions that modify only r0; - on arm64 jit replaces call to bpf_get_smp_processor_id() with a sequence of instructions that modify only r0 and tmp registers. These rewrites satisfy attribute no_caller_saved_registers contract. Allow rewrite of no_caller_saved_registers patterns for bpf_get_smp_processor_id() in order to use this function as a canary for no_caller_saved_registers tests. Signed-off-by:
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Yonghong Song authored
The following tests are added to verifier_ldsx.c: - sign extension of data/data_end/data_meta for tcx programs. The actual checking is in bpf_skb_is_valid_access() which is called by sk_filter, cg_skb, lwt, tc(tcx) and sk_skb. - sign extension of data/data_end/data_meta for xdp programs. - sign extension of data/data_end for flow_dissector programs. All newly-added tests have verification failure with message "invalid bpf_context access". Without previous patch, all these tests succeeded verification. Acked-by: -
Eduard Zingerman authored
GCC and LLVM define a no_caller_saved_registers function attribute. This attribute means that function scratches only some of the caller saved registers defined by ABI. For BPF the set of such registers could be defined as follows: - R0 is scratched only if function is non-void; - R1-R5 are scratched only if corresponding parameter type is defined in the function prototype. This commit introduces flag bpf_func_prot->allow_nocsr. If this flag is set for some helper function, verifier assumes that it follows no_caller_saved_registers calling convention. The contract between kernel and clang allows to simultaneously use such functions and maintain backwards compatibility with old kernels that don't understand no_caller_saved_registers calls (nocsr for short): - clang generates a simple pattern for nocsr calls, e.g.: r1 = 1; r2 = 2; *(u64 *)(r10 - 8) = r1; *(u64 *)(r10 - 16) = r2; call %[to_be_inlined] r2 = *(u64 *)(r10 - 16); r1 = *(u64 *)(r10 - 8); r0 = r1; r0 += r2; exit; - kernel removes unnecessary spills and fills, if called function is inlined by verifier or current JIT (with assumption that patch inserted by verifier or JIT honors nocsr contract, e.g. does not scratch r3-r5 for the example above), e.g. the code above would be transformed to: r1 = 1; r2 = 2; call %[to_be_inlined] r0 = r1; r0 += r2; exit; Technically, the transformation is split into the following phases: - function mark_nocsr_patterns(), called from bpf_check() searches and marks potential patterns in instruction auxiliary data; - upon stack read or write access, function check_nocsr_stack_contract() is used to verify if stack offsets, presumably reserved for nocsr patterns, are used only from those patterns; - function remove_nocsr_spills_fills(), called from bpf_check(), applies the rewrite for valid patterns. See comment in mark_nocsr_pattern_for_call() for more details. Suggested-by:Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by:
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Yonghong Song authored
syzbot reported a kernel crash due to commit 1f1e864b ("bpf: Handle sign-extenstin ctx member accesses"). The reason is due to sign-extension of 32-bit load for packet data/data_end/data_meta uapi field. The original code looks like: r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */ r3 = *(u32 *)(r1 + 80) /* load __sk_buff->data_end */ r0 = r2 r0 += 8 if r3 > r0 goto +1 ... Note that __sk_buff->data load has 32-bit sign extension. After verification and convert_ctx_accesses(), the final asm code looks like: r2 = *(u64 *)(r1 +208) r2 = (s32)r2 r3 = *(u64 *)(r1 +80) r0 = r2 r0 += 8 if r3 > r0 goto pc+1 ... Note that 'r2 = (s32)r2' may make the kernel __sk_buff->data address invalid which may cause runtime failure. Currently, in C code, typically we have void *data = (void *)(long)skb->data; void *data_end = (void *)(long)skb->data_end; ... and it will generate r2 = *(u64 *)(r1 +208) r3 = *(u64 *)(r1 +80) r0 = r2 r0 += 8 if r3 > r0 goto pc+1 If we allow sign-extension, void *data = (void *)(long)(int)skb->data; void *data_end = (void *)(long)skb->data_end; ... the generated code looks like r2 = *(u64 *)(r1 +208) r2 <<= 32 r2 s>>= 32 r3 = *(u64 *)(r1 +80) r0 = r2 r0 += 8 if r3 > r0 goto pc+1 and this will cause verification failure since "r2 <<= 32" is not allowed as "r2" is a packet pointer. To fix this issue for case r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */ this patch added additional checking in is_valid_access() callback function for packet data/data_end/data_meta access. If those accesses are with sign-extenstion, the verification will fail. [1] https://lore.kernel.org/bpf/000000000000c90eee061d236d37@google.com/ Reported-by: syzbot+ad9ec60c8eaf69e6f99c@syzkaller.appspotmail.com Fixes: 1f1e864b ("bpf: Handle sign-extenstin ctx member accesses") Acked-by:
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Eduard Zingerman authored
Extract the part of check_helper_call() as a utility function allowing to query 'struct bpf_func_proto' for a specific helper function id. Acked-by:
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Tony Ambardar authored
Actually use previously defined LDFLAGS during build and add support for LDLIBS to link extra standalone libraries e.g. 'argp' which is not provided by musl libc. Fixes: 585bf464 ("tools: runqslower: Add EXTRA_CFLAGS and EXTRA_LDFLAGS support") Signed-off-by:
Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/bpf/20240723003045.2273499-1-tony.ambardar@gmail.com
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Tony Ambardar authored
Make log output incorrectly shows 'test_maps' as the binary name for every 'CLNG-BPF' build step, apparently picking up the last value defined for the $(TRUNNER_BINARY) variable. Update the 'CLANG_BPF_BUILD_RULE' variants to fix this confusing output. Current output: CLNG-BPF [test_maps] access_map_in_map.bpf.o GEN-SKEL [test_progs] access_map_in_map.skel.h ... CLNG-BPF [test_maps] access_map_in_map.bpf.o GEN-SKEL [test_progs-no_alu32] access_map_in_map.skel.h ... CLNG-BPF [test_maps] access_map_in_map.bpf.o GEN-SKEL [test_progs-cpuv4] access_map_in_map.skel.h After fix: CLNG-BPF [test_progs] access_map_in_map.bpf.o GEN-SKEL [test_progs] access_map_in_map.skel.h ... CLNG-BPF [test_progs-no_alu32] access_map_in_map.bpf.o GEN-SKEL [test_progs-no_alu32] access_map_in_map.skel.h ... CLNG-BPF [test_progs-cpuv4] access_map_in_map.bpf.o GEN-SKEL [test_progs-cpuv4] access_map_in_map.skel.h Fixes: a5d0c26a ("selftests/bpf: Add a cpuv4 test runner for cpu=v4 testing") Fixes: 89ad7420 ("selftests/bpf: Drop the need for LLVM's llc") Signed-off-by:
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Andrii Nakryiko authored
Jiri Olsa says: ==================== selftests/bpf: Add more uprobe multi tests hi, adding more uprobe multi tests for failed attachments inside the uprobe register code. v3 changes: - renamed several variables/functions, null check [Andrii] - fixed CI issue thanks, jirka --- ==================== Link: https://lore.kernel.org/r/20240722202758.3889061-1-jolsa@kernel.orgSigned-off-by:
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Artem Savkov authored
Without CONFIG_NET_FOU bpf selftests are unable to build because of missing definitions. Add ___local versions of struct bpf_fou_encap and enum bpf_fou_encap_type to fix the issue. Signed-off-by:
Artem Savkov <asavkov@redhat.com> Signed-off-by:
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Jiri Olsa authored
Adding test that attaches/detaches multiple consumers on single uprobe and verifies all were hit as expected. Signed-off-by:
Jiri Olsa <jolsa@kernel.org> Signed-off-by:
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Tony Ambardar authored
Linking uprobe_multi.c on mips64el fails due to relocation overflows, when the GOT entries required exceeds the default maximum. Add a specific CFLAGS (-mxgot) for uprobe_multi.c on MIPS that allows using a larger GOT and avoids errors such as: /tmp/ccBTNQzv.o: in function `bench': uprobe_multi.c:49:(.text+0x1d7720): relocation truncated to fit: R_MIPS_GOT_DISP against `uprobe_multi_func_08188' uprobe_multi.c:49:(.text+0x1d7730): relocation truncated to fit: R_MIPS_GOT_DISP against `uprobe_multi_func_08189' ... collect2: error: ld returned 1 exit status Fixes: 519dfeaf ("selftests/bpf: Add uprobe_multi test program") Signed-off-by:
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Jiri Olsa authored
Adding tests for checking on recovery after failing to attach uprobe. Signed-off-by:
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Tony Ambardar authored
Update get_sys_includes in Makefile with missing MIPS-related definitions to fix many, many compilation errors building selftests/bpf. The following added defines drive conditional logic in system headers for word-size and endianness selection: MIPSEL, MIPSEB _MIPS_SZPTR _MIPS_SZLONG _MIPS_SIM, _ABIO32, _ABIN32, _ABI64 Signed-off-by:
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Ihor Solodrai authored
Ignore generated %.test.o dependencies when make goal is clean or docs-clean. Signed-off-by:
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Song Liu authored
Regular BPF hash map is not mmap-able from user space. However, map-in-map with outer map of type BPF_MAP_TYPE_HASH_OF_MAPS and mmap-able array as inner map can perform similar operations as a mmap-able hash map. This can be used by applications that benefit from fast accesses to some local data. Add a selftest to show this use case. Signed-off-by:
Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240723051455.1589192-1-song@kernel.orgSigned-off-by:
Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by:
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Martin KaFai Lau authored
Geliang Tang says: ==================== This set is part 10 of series "use network helpers" all BPF selftests wide. Patches 1-3 drop local functions make_client(), make_socket() and inetaddr_len() in sk_lookup.c. Patch 4 drops a useless function __start_server() in network_helpers.c. ==================== Signed-off-by:
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Geliang Tang authored
The helper start_server_addr() is a wrapper of __start_server(), the only difference between them is __start_server() accepts a sockaddr type address parameter, but start_server_addr() accepts a sockaddr_storage one. This patch drops __start_server(), and updates the callers to invoke start_server_addr() instead. Signed-off-by:
Geliang Tang <tanggeliang@kylinos.cn> Link: https://lore.kernel.org/r/31399df7cb957b7c233e79963b0aa0dc4278d273.1721475357.git.tanggeliang@kylinos.cnSigned-off-by:
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Geliang Tang authored
No need to use a dedicated helper inetaddr_len() to get the length of the IPv4 or IPv6 address, it can be got by make_sockaddr(), this patch drops it. Signed-off-by:
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Geliang Tang authored
This patch uses the public network helers client_socket() + make_sockaddr() in sk_lookup.c to create the client socket, set the timeout sockopts, and make the connecting address. The local defined function make_socket() can be dropped then. Signed-off-by:
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Geliang Tang authored
This patch uses the new helper connect_to_addr_str() in sk_lookup.c to create the client socket and connect to the server, instead of using local defined function make_client(). This local function can be dropped then. Signed-off-by:
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Alexei Starovoitov authored
test_progs-no_alu32 -t libbpf_get_fd_by_id_opts is being rejected by the verifier with the following error due to compiler optimization: 6: (67) r0 <<= 62 ; R0_w=scalar(smax=0x4000000000000000,umax=0xc000000000000000,smin32=0,smax32=umax32=0,var_off=(0x0; 0xc000000000000000)) 7: (c7) r0 s>>= 63 ; R0_w=scalar(smin=smin32=-1,smax=smax32=0) ; @ test_libbpf_get_fd_by_id_opts.c:0 8: (57) r0 &= -13 ; R0_w=scalar(smax=0x7ffffffffffffff3,umax=0xfffffffffffffff3,smax32=0x7ffffff3,umax32=0xfffffff3,var_off=(0x0; 0xfffffffffffffff3)) ; int BPF_PROG(check_access, struct bpf_map *map, fmode_t fmode) @ test_libbpf_get_fd_by_id_opts.c:27 9: (95) exit At program exit the register R0 has smax=9223372036854775795 should have been in [-4095, 0] Workaround by adding barrier(). Eventually the verifier will be able to recognize it. Fixes: 5d99e198 ("bpf, lsm: Add check for BPF LSM return value") Signed-off-by:
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Alexei Starovoitov authored
Xu Kuohai says: ==================== Add BPF LSM return value range check, BPF part From: Xu Kuohai <xukuohai@huawei.com> LSM BPF prog may make kernel panic when returning an unexpected value, such as returning positive value on hook file_alloc_security. To fix it, series [1] refactored LSM hook return values and added BPF return value check on top of that. Since the refactoring of LSM hooks and checking BPF prog return value patches is not closely related, this series separates BPF-related patches from [1]. v2: - Update Shung-Hsi's patch with [3] v1: https://lore.kernel.org/bpf/20240719081749.769748-1-xukuohai@huaweicloud.com/ Changes to [1]: 1. Extend LSM disabled list to include hooks refactored in [1] to avoid dependency on the hooks return value refactoring patches. 2. Replace the special case patch for bitwise AND on [-1, 0] with Shung-Hsi's general bitwise AND improvement patch [2]. 3. Remove unused patches. [1] https://lore.kernel.org/bpf/20240711111908.3817636-1-xukuohai@huaweicloud.com https://lore.kernel.org/bpf/20240711113828.3818398-1-xukuohai@huaweicloud.com [2] https://lore.kernel.org/bpf/ykuhustu7vt2ilwhl32kj655xfdgdlm2xkl5rff6tw2ycksovp@ss2n4gpjysnw [3] https://lore.kernel.org/bpf/20240719081702.137173-1-shung-hsi.yu@suse.com/ Shung-Hsi Yu (1): bpf, verifier: improve signed ranges inference for BPF_AND ==================== Link: https://lore.kernel.org/r/20240719110059.797546-1-xukuohai@huaweicloud.comSigned-off-by:
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Xu Kuohai authored
Add verifier tests to check bpf lsm return values and disabled hooks. Signed-off-by:
Xu Kuohai <xukuohai@huawei.com> Link: https://lore.kernel.org/r/20240719110059.797546-10-xukuohai@huaweicloud.comSigned-off-by:
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Xu Kuohai authored
Add test for lsm tail call to ensure tail call can only be used between bpf lsm progs attached to the same hook. Signed-off-by:
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Xu Kuohai authored
The return ranges of some bpf lsm test progs can not be deduced by the verifier accurately. To avoid erroneous rejections, add explicit return value checks for these progs. Signed-off-by:
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