Commit 898f55f5 authored by Eduard Zingerman's avatar Eduard Zingerman Committed by Martin KaFai Lau
Browse files

selftests/bpf: relax expected log messages to allow emitting BPF_ST 

Update [1] to LLVM BPF backend seeks to enable generation of BPF_ST
instruction when CPUv4 is selected. This affects expected log messages
for the following selftests:
- log_fixup/missing_map
- spin_lock/lock_id_mapval_preserve
- spin_lock/lock_id_innermapval_preserve

Expected messages in these tests hard-code instruction numbers for BPF
programs compiled from C. These instruction numbers change when
BPF_ST is allowed because single BPF_ST instruction replaces a pair of
BPF_MOV/BPF_STX instructions, e.g.:

    r1 = 42;
    *(u32 *)(r10 - 8) = r1;  --->  *(u32 *)(r10 - 8) = 42;

This commit updates expected log messages to avoid matching specific
instruction numbers (program position still could be uniquely
identified).

[1] https://reviews.llvm.org/D140804


    "[BPF] support for BPF_ST instruction in codegen"

Signed-off-by: default avatarEduard Zingerman <eddyz87@gmail.com>
Acked-by: default avatarYonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230808162755.392606-1-eddyz87@gmail.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent 96ead1e7

tools/testing/selftests/bpf/prog_tests/log_fixup.c

+1 −1
Original line number Diff line number Diff line
@@ -124,7 +124,7 @@ static void missing_map(void) 
	ASSERT_FALSE(bpf_map__autocreate(skel->maps.missing_map), "missing_map_autocreate");



	ASSERT_HAS_SUBSTR(log_buf,

			  "8: <invalid BPF map reference>\n"

			  ": <invalid BPF map reference>\n"

			  "BPF map 'missing_map' is referenced but wasn't created\n",

			  "log_buf");

tools/testing/selftests/bpf/prog_tests/spin_lock.c

+32 −5
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#include <regex.h>

#include <test_progs.h>

#include <network_helpers.h>
@@ -19,12 +20,16 @@ static struct { 
	  "; R1_w=map_value(off=0,ks=4,vs=4,imm=0)\n2: (85) call bpf_this_cpu_ptr#154\n"

	  "R1 type=map_value expected=percpu_ptr_" },

	{ "lock_id_mapval_preserve",

	  "8: (bf) r1 = r0                       ; R0_w=map_value(id=1,off=0,ks=4,vs=8,imm=0) "

	  "R1_w=map_value(id=1,off=0,ks=4,vs=8,imm=0)\n9: (85) call bpf_this_cpu_ptr#154\n"

	  "[0-9]\\+: (bf) r1 = r0                       ;"

	  " R0_w=map_value(id=1,off=0,ks=4,vs=8,imm=0)"

	  " R1_w=map_value(id=1,off=0,ks=4,vs=8,imm=0)\n"

	  "[0-9]\\+: (85) call bpf_this_cpu_ptr#154\n"

	  "R1 type=map_value expected=percpu_ptr_" },

	{ "lock_id_innermapval_preserve",

	  "13: (bf) r1 = r0                      ; R0=map_value(id=2,off=0,ks=4,vs=8,imm=0) "

	  "R1_w=map_value(id=2,off=0,ks=4,vs=8,imm=0)\n14: (85) call bpf_this_cpu_ptr#154\n"

	  "[0-9]\\+: (bf) r1 = r0                      ;"

	  " R0=map_value(id=2,off=0,ks=4,vs=8,imm=0)"

	  " R1_w=map_value(id=2,off=0,ks=4,vs=8,imm=0)\n"

	  "[0-9]\\+: (85) call bpf_this_cpu_ptr#154\n"

	  "R1 type=map_value expected=percpu_ptr_" },

	{ "lock_id_mismatch_kptr_kptr", "bpf_spin_unlock of different lock" },

	{ "lock_id_mismatch_kptr_global", "bpf_spin_unlock of different lock" },
@@ -45,6 +50,24 @@ static struct { 
	{ "lock_id_mismatch_innermapval_mapval", "bpf_spin_unlock of different lock" },

};



static int match_regex(const char *pattern, const char *string)

{

	int err, rc;

	regex_t re;



	err = regcomp(&re, pattern, REG_NOSUB);

	if (err) {

		char errbuf[512];



		regerror(err, &re, errbuf, sizeof(errbuf));

		PRINT_FAIL("Can't compile regex: %s\n", errbuf);

		return -1;

	}

	rc = regexec(&re, string, 0, NULL, 0);

	regfree(&re);

	return rc == 0 ? 1 : 0;

}



static void test_spin_lock_fail_prog(const char *prog_name, const char *err_msg)

{

	LIBBPF_OPTS(bpf_object_open_opts, opts, .kernel_log_buf = log_buf,
@@ -74,7 +97,11 @@ static void test_spin_lock_fail_prog(const char *prog_name, const char *err_msg) 
		goto end;

	}



	if (!ASSERT_OK_PTR(strstr(log_buf, err_msg), "expected error message")) {

	ret = match_regex(err_msg, log_buf);

	if (!ASSERT_GE(ret, 0, "match_regex"))

		goto end;



	if (!ASSERT_TRUE(ret, "no match for expected error message")) {

		fprintf(stderr, "Expected: %s\n", err_msg);

		fprintf(stderr, "Verifier: %s\n", log_buf);

	}