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2021-04-28bpf, selftests: Update array map tests for per-cpu batched opsPedro Tammela1-29/+75
Follows the same logic as the hashtable tests. Signed-off-by: Pedro Tammela <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-27bpf: Fix propagation of 32 bit unsigned bounds from 64 bit boundsDaniel Borkmann1-1/+1
Similarly as b02709587ea3 ("bpf: Fix propagation of 32-bit signed bounds from 64-bit bounds."), we also need to fix the propagation of 32 bit unsigned bounds from 64 bit counterparts. That is, really only set the u32_{min,max}_value when /both/ {umin,umax}_value safely fit in 32 bit space. For example, the register with a umin_value == 1 does /not/ imply that u32_min_value is also equal to 1, since umax_value could be much larger than 32 bit subregister can hold, and thus u32_min_value is in the interval [0,1] instead. Before fix, invalid tracking result of R2_w=inv1: [...] 5: R0_w=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv(id=0) R10=fp0 5: (35) if r2 >= 0x1 goto pc+1 [...] // goto path 7: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,umin_value=1) R10=fp0 7: (b6) if w2 <= 0x1 goto pc+1 [...] // goto path 9: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,smin_value=-9223372036854775807,smax_value=9223372032559808513,umin_value=1,umax_value=18446744069414584321,var_off=(0x1; 0xffffffff00000000),s32_min_value=1,s32_max_value=1,u32_max_value=1) R10=fp0 9: (bc) w2 = w2 10: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv1 R10=fp0 [...] After fix, correct tracking result of R2_w=inv(id=0,umax_value=1,var_off=(0x0; 0x1)): [...] 5: R0_w=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv(id=0) R10=fp0 5: (35) if r2 >= 0x1 goto pc+1 [...] // goto path 7: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,umin_value=1) R10=fp0 7: (b6) if w2 <= 0x1 goto pc+1 [...] // goto path 9: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,smax_value=9223372032559808513,umax_value=18446744069414584321,var_off=(0x0; 0xffffffff00000001),s32_min_value=0,s32_max_value=1,u32_max_value=1) R10=fp0 9: (bc) w2 = w2 10: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv(id=0,umax_value=1,var_off=(0x0; 0x1)) R10=fp0 [...] Thus, same issue as in b02709587ea3 holds for unsigned subregister tracking. Also, align __reg64_bound_u32() similarly to __reg64_bound_s32() as done in b02709587ea3 to make them uniform again. Fixes: 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") Reported-by: Manfred Paul (@_manfp) Signed-off-by: Daniel Borkmann <[email protected]> Reviewed-by: John Fastabend <[email protected]> Acked-by: Alexei Starovoitov <[email protected]>
2021-04-26selftests/bpf: Fix core_reloc test runnerAndrii Nakryiko1-8/+12
Fix failed tests checks in core_reloc test runner, which allowed failing tests to pass quietly. Also add extra check to make sure that expected to fail test cases with invalid names are caught as test failure anyway, as this is not an expected failure mode. Also fix mislabeled probed vs direct bitfield test cases. Fixes: 124a892d1c41 ("selftests/bpf: Test TYPE_EXISTS and TYPE_SIZE CO-RE relocations") Reported-by: Lorenz Bauer <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Lorenz Bauer <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-26selftests/bpf: Fix field existence CO-RE reloc testsAndrii Nakryiko9-48/+24
Negative field existence cases for have a broken assumption that FIELD_EXISTS CO-RE relo will fail for fields that match the name but have incompatible type signature. That's not how CO-RE relocations generally behave. Types and fields that match by name but not by expected type are treated as non-matching candidates and are skipped. Error later is reported if no matching candidate was found. That's what happens for most relocations, but existence relocations (FIELD_EXISTS and TYPE_EXISTS) are more permissive and they are designed to return 0 or 1, depending if a match is found. This allows to handle name-conflicting but incompatible types in BPF code easily. Combined with ___flavor suffixes, it's possible to handle pretty much any structural type changes in kernel within the compiled once BPF source code. So, long story short, negative field existence test cases are invalid in their assumptions, so this patch reworks them into a single consolidated positive case that doesn't match any of the fields. Fixes: c7566a69695c ("selftests/bpf: Add field existence CO-RE relocs tests") Reported-by: Lorenz Bauer <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Lorenz Bauer <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-26selftests/bpf: Fix BPF_CORE_READ_BITFIELD() macroAndrii Nakryiko1-4/+12
Fix BPF_CORE_READ_BITFIELD() macro used for reading CO-RE-relocatable bitfields. Missing breaks in a switch caused 8-byte reads always. This can confuse libbpf because it does strict checks that memory load size corresponds to the original size of the field, which in this case quite often would be wrong. After fixing that, we run into another problem, which quite subtle, so worth documenting here. The issue is in Clang optimization and CO-RE relocation interactions. Without that asm volatile construct (also known as barrier_var()), Clang will re-order BYTE_OFFSET and BYTE_SIZE relocations and will apply BYTE_OFFSET 4 times for each switch case arm. This will result in the same error from libbpf about mismatch of memory load size and original field size. I.e., if we were reading u32, we'd still have *(u8 *), *(u16 *), *(u32 *), and *(u64 *) memory loads, three of which will fail. Using barrier_var() forces Clang to apply BYTE_OFFSET relocation first (and once) to calculate p, after which value of p is used without relocation in each of switch case arms, doing appropiately-sized memory load. Here's the list of relevant relocations and pieces of generated BPF code before and after this patch for test_core_reloc_bitfields_direct selftests. BEFORE ===== #45: core_reloc: insn #160 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32 #46: core_reloc: insn #167 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #47: core_reloc: insn #174 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #48: core_reloc: insn #178 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #49: core_reloc: insn #182 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 157: 18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll 159: 7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1 160: b7 02 00 00 04 00 00 00 r2 = 4 ; BYTE_SIZE relocation here ^^^ 161: 66 02 07 00 03 00 00 00 if w2 s> 3 goto +7 <LBB0_63> 162: 16 02 0d 00 01 00 00 00 if w2 == 1 goto +13 <LBB0_65> 163: 16 02 01 00 02 00 00 00 if w2 == 2 goto +1 <LBB0_66> 164: 05 00 12 00 00 00 00 00 goto +18 <LBB0_69> 0000000000000528 <LBB0_66>: 165: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 167: 69 11 08 00 00 00 00 00 r1 = *(u16 *)(r1 + 8) ; BYTE_OFFSET relo here w/ WRONG size ^^^^^^^^^^^^^^^^ 168: 05 00 0e 00 00 00 00 00 goto +14 <LBB0_69> 0000000000000548 <LBB0_63>: 169: 16 02 0a 00 04 00 00 00 if w2 == 4 goto +10 <LBB0_67> 170: 16 02 01 00 08 00 00 00 if w2 == 8 goto +1 <LBB0_68> 171: 05 00 0b 00 00 00 00 00 goto +11 <LBB0_69> 0000000000000560 <LBB0_68>: 172: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 174: 79 11 08 00 00 00 00 00 r1 = *(u64 *)(r1 + 8) ; BYTE_OFFSET relo here w/ WRONG size ^^^^^^^^^^^^^^^^ 175: 05 00 07 00 00 00 00 00 goto +7 <LBB0_69> 0000000000000580 <LBB0_65>: 176: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 178: 71 11 08 00 00 00 00 00 r1 = *(u8 *)(r1 + 8) ; BYTE_OFFSET relo here w/ WRONG size ^^^^^^^^^^^^^^^^ 179: 05 00 03 00 00 00 00 00 goto +3 <LBB0_69> 00000000000005a0 <LBB0_67>: 180: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 182: 61 11 08 00 00 00 00 00 r1 = *(u32 *)(r1 + 8) ; BYTE_OFFSET relo here w/ RIGHT size ^^^^^^^^^^^^^^^^ 00000000000005b8 <LBB0_69>: 183: 67 01 00 00 20 00 00 00 r1 <<= 32 184: b7 02 00 00 00 00 00 00 r2 = 0 185: 16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71> 186: c7 01 00 00 20 00 00 00 r1 s>>= 32 187: 05 00 01 00 00 00 00 00 goto +1 <LBB0_72> 00000000000005e0 <LBB0_71>: 188: 77 01 00 00 20 00 00 00 r1 >>= 32 AFTER ===== #30: core_reloc: insn #132 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #31: core_reloc: insn #134 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32 129: 18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll 131: 7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1 132: b7 01 00 00 08 00 00 00 r1 = 8 ; BYTE_OFFSET relo here ^^^ ; no size check for non-memory dereferencing instructions 133: 0f 12 00 00 00 00 00 00 r2 += r1 134: b7 03 00 00 04 00 00 00 r3 = 4 ; BYTE_SIZE relocation here ^^^ 135: 66 03 05 00 03 00 00 00 if w3 s> 3 goto +5 <LBB0_63> 136: 16 03 09 00 01 00 00 00 if w3 == 1 goto +9 <LBB0_65> 137: 16 03 01 00 02 00 00 00 if w3 == 2 goto +1 <LBB0_66> 138: 05 00 0a 00 00 00 00 00 goto +10 <LBB0_69> 0000000000000458 <LBB0_66>: 139: 69 21 00 00 00 00 00 00 r1 = *(u16 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 140: 05 00 08 00 00 00 00 00 goto +8 <LBB0_69> 0000000000000468 <LBB0_63>: 141: 16 03 06 00 04 00 00 00 if w3 == 4 goto +6 <LBB0_67> 142: 16 03 01 00 08 00 00 00 if w3 == 8 goto +1 <LBB0_68> 143: 05 00 05 00 00 00 00 00 goto +5 <LBB0_69> 0000000000000480 <LBB0_68>: 144: 79 21 00 00 00 00 00 00 r1 = *(u64 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 145: 05 00 03 00 00 00 00 00 goto +3 <LBB0_69> 0000000000000490 <LBB0_65>: 146: 71 21 00 00 00 00 00 00 r1 = *(u8 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 147: 05 00 01 00 00 00 00 00 goto +1 <LBB0_69> 00000000000004a0 <LBB0_67>: 148: 61 21 00 00 00 00 00 00 r1 = *(u32 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 00000000000004a8 <LBB0_69>: 149: 67 01 00 00 20 00 00 00 r1 <<= 32 150: b7 02 00 00 00 00 00 00 r2 = 0 151: 16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71> 152: c7 01 00 00 20 00 00 00 r1 s>>= 32 153: 05 00 01 00 00 00 00 00 goto +1 <LBB0_72> 00000000000004d0 <LBB0_71>: 154: 77 01 00 00 20 00 00 00 r1 >>= 323 Fixes: ee26dade0e3b ("libbpf: Add support for relocatable bitfields") Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Lorenz Bauer <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-26libbpf: Support BTF_KIND_FLOAT during type compatibility checks in CO-REAndrii Nakryiko1-2/+4
Add BTF_KIND_FLOAT support when doing CO-RE field type compatibility check. Without this, relocations against float/double fields will fail. Also adjust one error message to emit instruction index instead of less convenient instruction byte offset. Fixes: 22541a9eeb0d ("libbpf: Add BTF_KIND_FLOAT support") Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Lorenz Bauer <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-26selftests/bpf: Add remaining ASSERT_xxx() variantsAndrii Nakryiko7-15/+56
Add ASSERT_TRUE/ASSERT_FALSE for conditions calculated with custom logic to true/false. Also add remaining arithmetical assertions: - ASSERT_LE -- less than or equal; - ASSERT_GT -- greater than; - ASSERT_GE -- greater than or equal. This should cover most scenarios where people fall back to error-prone CHECK()s. Also extend ASSERT_ERR() to print out errno, in addition to direct error. Also convert few CHECK() instances to ensure new ASSERT_xxx() variants work as expected. Subsequent patch will also use ASSERT_TRUE/ASSERT_FALSE more extensively. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Lorenz Bauer <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-25selftests/bpf: Use ASSERT macros in lsm testJiri Olsa1-17/+10
Replacing CHECK with ASSERT macros. Suggested-by: Andrii Nakryiko <[email protected]> Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-25selftests/bpf: Test that module can't be unloaded with attached trampolineJiri Olsa1-0/+23
Adding test to verify that once we attach module's trampoline, the module can't be unloaded. Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-25selftests/bpf: Add re-attach test to lsm testJiri Olsa1-10/+38
Adding the test to re-attach (detach/attach again) lsm programs, plus check that already linked program can't be attached again. Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-25selftests/bpf: Add re-attach test to fexit_testJiri Olsa1-15/+37
Adding the test to re-attach (detach/attach again) tracing fexit programs, plus check that already linked program can't be attached again. Also switching to ASSERT* macros. Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-25selftests/bpf: Add re-attach test to fentry_testJiri Olsa1-15/+37
Adding the test to re-attach (detach/attach again) tracing fentry programs, plus check that already linked program can't be attached again. Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller47-497/+2559
Alexei Starovoitov says: ==================== pull-request: bpf-next 2021-04-23 The following pull-request contains BPF updates for your *net-next* tree. We've added 69 non-merge commits during the last 22 day(s) which contain a total of 69 files changed, 3141 insertions(+), 866 deletions(-). The main changes are: 1) Add BPF static linker support for extern resolution of global, from Andrii. 2) Refine retval for bpf_get_task_stack helper, from Dave. 3) Add a bpf_snprintf helper, from Florent. 4) A bunch of miscellaneous improvements from many developers. ==================== Signed-off-by: David S. Miller <[email protected]>
2021-04-23selftests/net: bump timeout to 5 minutesPo-Hsu Lin2-0/+3
We found that with the latest mainline kernel (5.12.0-051200rc8) on some KVM instances / bare-metal systems, the following tests will take longer than the kselftest framework default timeout (45 seconds) to run and thus got terminated with TIMEOUT error: * xfrm_policy.sh - took about 2m20s * pmtu.sh - took about 3m5s * udpgso_bench.sh - took about 60s Bump the timeout setting to 5 minutes to allow them have a chance to finish. https://bugs.launchpad.net/bugs/1856010 Signed-off-by: Po-Hsu Lin <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2021-04-23selftests: mptcp: add a test case for MSG_PEEKYonglong Li2-8/+69
Extend mptcp_connect tool with MSG_PEEK support and add a test case in mptcp_connect.sh that checks the data received from/after recv() with MSG_PEEK. Acked-by: Paolo Abeni <[email protected]> Co-developed-by: Matthieu Baerts <[email protected]> Signed-off-by: Matthieu Baerts <[email protected]> Signed-off-by: Yonglong Li <[email protected]> Signed-off-by: Mat Martineau <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2021-04-23selftests/bpf: Document latest Clang fix expectations for linking testsAndrii Nakryiko1-0/+9
Document which fixes are required to generate correct static linking selftests. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23selftests/bpf: Add map linking selftestAndrii Nakryiko4-1/+191
Add selftest validating various aspects of statically linking BTF-defined map definitions. Legacy map definitions do not support extern resolution between object files. Some of the aspects validated: - correct resolution of extern maps against concrete map definitions; - extern maps can currently only specify map type and key/value size and/or type information; - weak concrete map definitions are resolved properly. Static map definitions are not yet supported by libbpf, so they are not explicitly tested, though manual testing showes that BPF linker handles them properly. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23selftests/bpf: Add global variables linking selftestAndrii Nakryiko4-1/+154
Add selftest validating various aspects of statically linking global variables: - correct resolution of extern variables across .bss, .data, and .rodata sections; - correct handling of weak definitions; - correct de-duplication of repeating special externs (.kconfig, .ksyms). Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23selftests/bpf: Add function linking selftestAndrii Nakryiko4-1/+190
Add selftest validating various aspects of statically linking functions: - no conflicts and correct resolution for name-conflicting static funcs; - correct resolution of extern functions; - correct handling of weak functions, both resolution itself and libbpf's handling of unused weak function that "lost" (it leaves gaps in code with no ELF symbols); - correct handling of hidden visibility to turn global function into "static" for the purpose of BPF verification. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23selftests/bpf: Omit skeleton generation for multi-linked BPF object filesAndrii Nakryiko1-1/+3
Skip generating individual BPF skeletons for files that are supposed to be linked together to form the final BPF object file. Very often such files are "incomplete" BPF object files, which will fail libbpf bpf_object__open() step, if used individually, thus failing BPF skeleton generation. This is by design, so skip individual BPF skeletons and only validate them as part of their linked final BPF object file and skeleton. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23selftests/bpf: Use -O0 instead of -Og in selftests buildsAndrii Nakryiko1-4/+4
While -Og is designed to work well with debugger, it's still inferior to -O0 in terms of debuggability experience. It will cause some variables to still be inlined, it will also prevent single-stepping some statements and otherwise interfere with debugging experience. So switch to -O0 which turns off any optimization and provides the best debugging experience. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23libbpf: Support extern resolution for BTF-defined maps in .maps sectionAndrii Nakryiko1-0/+132
Add extra logic to handle map externs (only BTF-defined maps are supported for linking). Re-use the map parsing logic used during bpf_object__open(). Map externs are currently restricted to always match complete map definition. So all the specified attributes will be compared (down to pining, map_flags, numa_node, etc). In the future this restriction might be relaxed with no backwards compatibility issues. If any attribute is mismatched between extern and actual map definition, linker will report an error, pointing out which one mismatches. The original intent was to allow for extern to specify attributes that matters (to user) to enforce. E.g., if you specify just key information and omit value, then any value fits. Similarly, it should have been possible to enforce map_flags, pinning, and any other possible map attribute. Unfortunately, that means that multiple externs can be only partially overlapping with each other, which means linker would need to combine their type definitions to end up with the most restrictive and fullest map definition. This requires an extra amount of BTF manipulation which at this time was deemed unnecessary and would require further extending generic BTF writer APIs. So that is left for future follow ups, if there will be demand for that. But the idea seems intresting and useful, so I want to document it here. Weak definitions are also supported, but are pretty strict as well, just like externs: all weak map definitions have to match exactly. In the follow up patches this most probably will be relaxed, with __weak map definitions being able to differ between each other (with non-weak definition always winning, of course). Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23libbpf: Add linker extern resolution support for functions and global variablesAndrii Nakryiko1-59/+790
Add BPF static linker logic to resolve extern variables and functions across multiple linked together BPF object files. For that, linker maintains a separate list of struct glob_sym structures, which keeps track of few pieces of metadata (is it extern or resolved global, is it a weak symbol, which ELF section it belongs to, etc) and ties together BTF type info and ELF symbol information and keeps them in sync. With adding support for extern variables/funcs, it's now possible for some sections to contain both extern and non-extern definitions. This means that some sections may start out as ephemeral (if only externs are present and thus there is not corresponding ELF section), but will be "upgraded" to actual ELF section as symbols are resolved or new non-extern definitions are appended. Additional care is taken to not duplicate extern entries in sections like .kconfig and .ksyms. Given libbpf requires BTF type to always be present for .kconfig/.ksym externs, linker extends this requirement to all the externs, even those that are supposed to be resolved during static linking and which won't be visible to libbpf. With BTF information always present, static linker will check not just ELF symbol matches, but entire BTF type signature match as well. That logic is stricter that BPF CO-RE checks. It probably should be re-used by .ksym resolution logic in libbpf as well, but that's left for follow up patches. To make it unnecessary to rewrite ELF symbols and minimize BTF type rewriting/removal, ELF symbols that correspond to externs initially will be updated in place once they are resolved. Similarly for BTF type info, VAR/FUNC and var_secinfo's (sec_vars in struct bpf_linker) are staying stable, but types they point to might get replaced when extern is resolved. This might leave some left-over types (even though we try to minimize this for common cases of having extern funcs with not argument names vs concrete function with names properly specified). That can be addresses later with a generic BTF garbage collection. That's left for a follow up as well. Given BTF type appending phase is separate from ELF symbol appending/resolution, special struct glob_sym->underlying_btf_id variable is used to communicate resolution and rewrite decisions. 0 means underlying_btf_id needs to be appended (it's not yet in final linker->btf), <0 values are used for temporary storage of source BTF type ID (not yet rewritten), so -glob_sym->underlying_btf_id is BTF type id in obj-btf. But by the end of linker_append_btf() phase, that underlying_btf_id will be remapped and will always be > 0. This is the uglies part of the whole process, but keeps the other parts much simpler due to stability of sec_var and VAR/FUNC types, as well as ELF symbol, so please keep that in mind while reviewing. BTF-defined maps require some extra custom logic and is addressed separate in the next patch, so that to keep this one smaller and easier to review. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23libbpf: Tighten BTF type ID rewriting with error checkingAndrii Nakryiko1-0/+7
It should never fail, but if it does, it's better to know about this rather than end up with nonsensical type IDs. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23libbpf: Extend sanity checking ELF symbols with externs validationAndrii Nakryiko1-9/+40
Add logic to validate extern symbols, plus some other minor extra checks, like ELF symbol #0 validation, general symbol visibility and binding validations. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23libbpf: Make few internal helpers available outside of libbpf.cAndrii Nakryiko3-18/+16
Make skip_mods_and_typedefs(), btf_kind_str(), and btf_func_linkage() helpers available outside of libbpf.c, to be used by static linker code. Also do few cleanups (error code fixes, comment clean up, etc) that don't deserve their own commit. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23libbpf: Factor out symtab and relos sanity checksAndrii Nakryiko1-106/+127
Factor out logic for sanity checking SHT_SYMTAB and SHT_REL sections into separate sections. They are already quite extensive and are suffering from too deep indentation. Subsequent changes will extend SYMTAB sanity checking further, so it's better to factor each into a separate function. No functional changes are intended. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23libbpf: Refactor BTF map definition parsingAndrii Nakryiko2-111/+178
Refactor BTF-defined maps parsing logic to allow it to be nicely reused by BPF static linker. Further, at least for BPF static linker, it's important to know which attributes of a BPF map were defined explicitly, so provide a bit set for each known portion of BTF map definition. This allows BPF static linker to do a simple check when dealing with extern map declarations. The same capabilities allow to distinguish attributes explicitly set to zero (e.g., __uint(max_entries, 0)) vs the case of not specifying it at all (no max_entries attribute at all). Libbpf is currently not utilizing that, but it could be useful for backwards compatibility reasons later. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23libbpf: Allow gaps in BPF program sections to support overriden weak functionsAndrii Nakryiko1-36/+22
Currently libbpf is very strict about parsing BPF program instruction sections. No gaps are allowed between sequential BPF programs within a given ELF section. Libbpf enforced that by keeping track of the next section offset that should start a new BPF (sub)program and cross-checks that by searching for a corresponding STT_FUNC ELF symbol. But this is too restrictive once we allow to have weak BPF programs and link together two or more BPF object files. In such case, some weak BPF programs might be "overridden" by either non-weak BPF program with the same name and signature, or even by another weak BPF program that just happened to be linked first. That, in turn, leaves BPF instructions of the "lost" BPF (sub)program intact, but there is no corresponding ELF symbol, because no one is going to be referencing it. Libbpf already correctly handles such cases in the sense that it won't append such dead code to actual BPF programs loaded into kernel. So the only change that needs to be done is to relax the logic of parsing BPF instruction sections. Instead of assuming next BPF (sub)program section offset, iterate available STT_FUNC ELF symbols to discover all available BPF subprograms and programs. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23libbpf: Mark BPF subprogs with hidden visibility as static for BPF verifierAndrii Nakryiko4-6/+58
Define __hidden helper macro in bpf_helpers.h, which is a short-hand for __attribute__((visibility("hidden"))). Add libbpf support to mark BPF subprograms marked with __hidden as static in BTF information to enforce BPF verifier's static function validation algorithm, which takes more information (caller's context) into account during a subprogram validation. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23libbpf: Suppress compiler warning when using SEC() macro with externsAndrii Nakryiko1-2/+9
When used on externs SEC() macro will trigger compilation warning about inapplicable `__attribute__((used))`. That's expected for extern declarations, so suppress it with the corresponding _Pragma. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23bpftool: Dump more info about DATASEC membersAndrii Nakryiko1-8/+18
Dump succinct information for each member of DATASEC: its kinds and name. This is extremely helpful to see at a quick glance what is inside each DATASEC of a given BTF. Without this, one has to jump around BTF data to just find out the name of a VAR or FUNC. DATASEC's var_secinfo member is special in that regard because it doesn't itself contain the name of the member, delegating that to the referenced VAR and FUNC kinds. Other kinds, like STRUCT/UNION/FUNC/ENUM, encode member names directly and thus are clearly identifiable in BTF dump. The new output looks like this: [35] DATASEC '.bss' size=0 vlen=6 type_id=8 offset=0 size=4 (VAR 'input_bss1') type_id=13 offset=0 size=4 (VAR 'input_bss_weak') type_id=16 offset=0 size=4 (VAR 'output_bss1') type_id=17 offset=0 size=4 (VAR 'output_data1') type_id=18 offset=0 size=4 (VAR 'output_rodata1') type_id=20 offset=0 size=8 (VAR 'output_sink1') [36] DATASEC '.data' size=0 vlen=2 type_id=9 offset=0 size=4 (VAR 'input_data1') type_id=14 offset=0 size=4 (VAR 'input_data_weak') [37] DATASEC '.kconfig' size=0 vlen=2 type_id=25 offset=0 size=4 (VAR 'LINUX_KERNEL_VERSION') type_id=28 offset=0 size=1 (VAR 'CONFIG_BPF_SYSCALL') [38] DATASEC '.ksyms' size=0 vlen=1 type_id=30 offset=0 size=1 (VAR 'bpf_link_fops') [39] DATASEC '.rodata' size=0 vlen=2 type_id=12 offset=0 size=4 (VAR 'input_rodata1') type_id=15 offset=0 size=4 (VAR 'input_rodata_weak') [40] DATASEC 'license' size=0 vlen=1 type_id=24 offset=0 size=4 (VAR 'LICENSE') Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23bpftool: Support dumping BTF VAR's "extern" linkageAndrii Nakryiko1-1/+3
Add dumping of "extern" linkage for BTF VAR kind. Also shorten "global-allocated" to "global" to be in line with FUNC's "global". Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-23selftests: mlxsw: Fix mausezahn invocation in ERSPAN scale testPetr Machata2-3/+19
The mirror_gre_scale test creates as many ERSPAN sessions as the underlying chip supports, and tests that they all work. In order to determine that it issues a stream of ICMP packets and checks if they are mirrored as expected. However, the mausezahn invocation missed the -6 flag to identify the use of IPv6 protocol, and was sending ICMP messages over IPv6, as opposed to ICMP6. It also didn't pass an explicit source IP address, which apparently worked at some point in the past, but does not anymore. To fix these issues, extend the function mirror_test() in mirror_lib by detecting the IPv6 protocol addresses, and using a different ICMP scheme. Fix __mirror_gre_test() in the selftest itself to pass a source IP address. Signed-off-by: Petr Machata <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2021-04-23selftests: mlxsw: Increase the tolerance of backlog buildupPetr Machata1-2/+2
The intention behind this test is to make sure that qdisc limit is correctly projected to the HW. However, first, due to rounding in the qdisc, and then in the driver, the number cannot actually be accurate. And second, the approach to testing this is to oversubscribe the port with traffic generated on the same switch. The actual backlog size therefore fluctuates. In practice, this test proved to be noisier than the rest, and spuriously fails every now and then. Increase the tolerance to 10 % to avoid these issues. Signed-off-by: Petr Machata <[email protected]> Acked-by: Jiri Pirko <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2021-04-23selftests: mlxsw: Return correct error code in resource scale testsDanielle Ratson2-2/+6
Currently, the resource scale test checks a few cases, when the error code resets between the cases. So for example, if one case fails and the consecutive case passes, the error code eventually will fit the last test and will be 0. Save a new return code that will hold the 'or' return codes of all the cases, so the final return code will consider all the cases. Signed-off-by: Danielle Ratson <[email protected]> Reviewed-by: Petr Machata <[email protected]> Signed-off-by: Petr Machata <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2021-04-23selftests: mlxsw: Remove a redundant if statement in tc_flower_scale testDanielle Ratson1-5/+1
Currently, the error return code of the failure condition is lost after using an if statement, so the test doesn't fail when it should. Remove the if statement that separates the condition and the error code check, so the test won't always pass. Fixes: abfce9e062021 ("selftests: mlxsw: Reduce running time using offload indication") Reported-by: Ido Schimmel <[email protected]> Signed-off-by: Danielle Ratson <[email protected]> Reviewed-by: Petr Machata <[email protected]> Signed-off-by: Petr Machata <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2021-04-23selftests: mlxsw: Remove a redundant if statement in port_scale testDanielle Ratson1-5/+1
Currently, the error return code of the failure condition is lost after using an if statement, so the test doesn't fail when it should. Remove the if statement that separates the condition and the error code check, so the test won't always pass. Fixes: 5154b1b826d9b ("selftests: mlxsw: Add a scale test for physical ports") Reported-by: Ido Schimmel <[email protected]> Signed-off-by: Danielle Ratson <[email protected]> Reviewed-by: Petr Machata <[email protected]> Signed-off-by: Petr Machata <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2021-04-23selftests: net: mirror_gre_vlan_bridge_1q: Make an FDB entry staticPetr Machata1-1/+1
The FDB roaming test installs a destination MAC address on the wrong interface of an FDB database and tests whether the mirroring fails, because packets are sent to the wrong port. The test by mistake installs the FDB entry as local. This worked previously, because drivers were notified of local FDB entries in the same way as of static entries. However that has been fixed in the commit 6ab4c3117aec ("net: bridge: don't notify switchdev for local FDB addresses"), and local entries are not notified anymore. As a result, the HW is not reconfigured for the FDB roam, and mirroring keeps working, failing the test. To fix the issue, mark the FDB entry as static. Fixes: 9c7c8a82442c ("selftests: forwarding: mirror_gre_vlan_bridge_1q: Add more tests") Signed-off-by: Petr Machata <[email protected]> Reviewed-by: Ido Schimmel <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2021-04-20selftests: mlxsw: sch_red_ets: Test proper counter cleaning in ETSPetr Machata1-0/+7
There was a bug introduced during the rework which cause non-zero backlog being stuck at ETS. Introduce a selftest that would have caught the issue earlier. Signed-off-by: Petr Machata <[email protected]> Reviewed-by: Ido Schimmel <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2021-04-20selftests/bpf: Add docs target as all dependencyJiri Olsa1-1/+2
Currently docs target is make dependency for TEST_GEN_FILES, which makes tests to be rebuilt every time you run make. Adding docs as all target dependency, so when running make on top of built selftests it will show just: $ make make[1]: Nothing to be done for 'docs'. After cleaning docs, only docs is rebuilt: $ make docs-clean CLEAN eBPF_helpers-manpage CLEAN eBPF_syscall-manpage $ make GEN ...selftests/bpf/bpf-helpers.rst GEN ...selftests/bpf/bpf-helpers.7 GEN ...selftests/bpf/bpf-syscall.rst GEN ...selftests/bpf/bpf-syscall.2 $ make make[1]: Nothing to be done for 'docs'. Fixes: a01d935b2e09 ("tools/bpf: Remove bpf-helpers from bpftool docs") Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-19bpf/selftests: Add bpf_get_task_stack retval bounds test_progDave Marchevsky2-0/+28
Add a libbpf test prog which feeds bpf_get_task_stack's return value into seq_write after confirming it's positive. No attempt to bound the value from above is made. Load will fail if verifier does not refine retval range based on buf sz input to bpf_get_task_stack. Signed-off-by: Dave Marchevsky <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Song Liu <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-19bpf/selftests: Add bpf_get_task_stack retval bounds verifier testDave Marchevsky1-0/+43
Add a bpf_iter test which feeds bpf_get_task_stack's return value into seq_write after confirming it's positive. No attempt to bound the value from above is made. Load will fail if verifier does not refine retval range based on buf sz input to bpf_get_task_stack. Signed-off-by: Dave Marchevsky <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Song Liu <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller1-1/+151
Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for net-next: 1) Add vlan match and pop actions to the flowtable offload, patches from wenxu. 2) Reduce size of the netns_ct structure, which itself is embedded in struct net Make netns_ct a read-mostly structure. Patches from Florian Westphal. 3) Add FLOW_OFFLOAD_XMIT_UNSPEC to skip dst check from garbage collector path, as required by the tc CT action. From Roi Dayan. 4) VLAN offload fixes for nftables: Allow for matching on both s-vlan and c-vlan selectors. Fix match of VLAN id due to incorrect byteorder. Add a new routine to properly populate flow dissector ethertypes. 5) Missing keys in ip{6}_route_me_harder() results in incorrect routes. This includes an update for selftest infra. Patches from Ido Schimmel. 6) Add counter hardware offload support through FLOW_CLS_STATS. ==================== Signed-off-by: David S. Miller <[email protected]>
2021-04-19selftests/bpf: Add a series of tests for bpf_snprintfFlorent Revest3-0/+218
The "positive" part tests all format specifiers when things go well. The "negative" part makes sure that incorrect format strings fail at load time. Signed-off-by: Florent Revest <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-19libbpf: Introduce a BPF_SNPRINTF helper macroFlorent Revest1-0/+18
Similarly to BPF_SEQ_PRINTF, this macro turns variadic arguments into an array of u64, making it more natural to call the bpf_snprintf helper. Signed-off-by: Florent Revest <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-19libbpf: Initialize the bpf_seq_printf parameters array field by fieldFlorent Revest1-11/+29
When initializing the __param array with a one liner, if all args are const, the initial array value will be placed in the rodata section but because libbpf does not support relocation in the rodata section, any pointer in this array will stay NULL. Fixes: c09add2fbc5a ("tools/libbpf: Add bpf_iter support") Signed-off-by: Florent Revest <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-19bpf: Add a bpf_snprintf helperFlorent Revest1-0/+28
The implementation takes inspiration from the existing bpf_trace_printk helper but there are a few differences: To allow for a large number of format-specifiers, parameters are provided in an array, like in bpf_seq_printf. Because the output string takes two arguments and the array of parameters also takes two arguments, the format string needs to fit in one argument. Thankfully, ARG_PTR_TO_CONST_STR is guaranteed to point to a zero-terminated read-only map so we don't need a format string length arg. Because the format-string is known at verification time, we also do a first pass of format string validation in the verifier logic. This makes debugging easier. Signed-off-by: Florent Revest <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-04-19selftests: fib_nexthops: Test large scale nexthop flushingIdo Schimmel1-0/+15
Test that all the nexthops are flushed when a multi-part nexthop dump is required for the flushing. Without previous patch: # ./fib_nexthops.sh TEST: Large scale nexthop flushing [FAIL] With previous patch: # ./fib_nexthops.sh TEST: Large scale nexthop flushing [ OK ] Signed-off-by: Ido Schimmel <[email protected]> Reviewed-by: Petr Machata <[email protected]> Reviewed-by: David Ahern <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2021-04-18selftests: fib_tests: Add test cases for interaction with manglingIdo Schimmel1-1/+151
Test that packets are correctly routed when netfilter mangling rules are present. Without previous patch: # ./fib_tests.sh -t ipv4_mangle IPv4 mangling tests TEST: Connection with correct parameters [ OK ] TEST: Connection with incorrect parameters [ OK ] TEST: Connection with correct parameters - mangling [FAIL] TEST: Connection with correct parameters - no mangling [ OK ] TEST: Connection check - server side [FAIL] Tests passed: 3 Tests failed: 2 # ./fib_tests.sh -t ipv6_mangle IPv6 mangling tests TEST: Connection with correct parameters [ OK ] TEST: Connection with incorrect parameters [ OK ] TEST: Connection with correct parameters - mangling [FAIL] TEST: Connection with correct parameters - no mangling [ OK ] TEST: Connection check - server side [FAIL] Tests passed: 3 Tests failed: 2 With previous patch: # ./fib_tests.sh -t ipv4_mangle IPv4 mangling tests TEST: Connection with correct parameters [ OK ] TEST: Connection with incorrect parameters [ OK ] TEST: Connection with correct parameters - mangling [ OK ] TEST: Connection with correct parameters - no mangling [ OK ] TEST: Connection check - server side [ OK ] Tests passed: 5 Tests failed: 0 # ./fib_tests.sh -t ipv6_mangle IPv6 mangling tests TEST: Connection with correct parameters [ OK ] TEST: Connection with incorrect parameters [ OK ] TEST: Connection with correct parameters - mangling [ OK ] TEST: Connection with correct parameters - no mangling [ OK ] TEST: Connection check - server side [ OK ] Tests passed: 5 Tests failed: 0 Signed-off-by: Ido Schimmel <[email protected]> Reviewed-by: David Ahern <[email protected]> Signed-off-by: Pablo Neira Ayuso <[email protected]>