From a549aaa67395eea89c2b9d2bea01ab0455b18408 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Sun, 15 Aug 2021 00:06:06 -0700 Subject: [PATCH] selftests/bpf: Extract uprobe-related helpers into trace_helpers.{c,h} Extract two helpers used for working with uprobes into trace_helpers.{c,h} to be re-used between multiple uprobe-using selftests. Also rename get_offset() into more appropriate get_uprobe_offset(). Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20210815070609.987780-14-andrii@kernel.org --- .../selftests/bpf/prog_tests/attach_probe.c | 61 +------------------- tools/testing/selftests/bpf/trace_helpers.c | 66 ++++++++++++++++++++++ tools/testing/selftests/bpf/trace_helpers.h | 3 + 3 files changed, 70 insertions(+), 60 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c index ec11e20..e40b41c 100644 --- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c +++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c @@ -2,65 +2,6 @@ #include #include "test_attach_probe.skel.h" -#if defined(__powerpc64__) && defined(_CALL_ELF) && _CALL_ELF == 2 - -#define OP_RT_RA_MASK 0xffff0000UL -#define LIS_R2 0x3c400000UL -#define ADDIS_R2_R12 0x3c4c0000UL -#define ADDI_R2_R2 0x38420000UL - -static ssize_t get_offset(ssize_t addr, ssize_t base) -{ - u32 *insn = (u32 *) addr; - - /* - * A PPC64 ABIv2 function may have a local and a global entry - * point. We need to use the local entry point when patching - * functions, so identify and step over the global entry point - * sequence. - * - * The global entry point sequence is always of the form: - * - * addis r2,r12,XXXX - * addi r2,r2,XXXX - * - * A linker optimisation may convert the addis to lis: - * - * lis r2,XXXX - * addi r2,r2,XXXX - */ - if ((((*insn & OP_RT_RA_MASK) == ADDIS_R2_R12) || - ((*insn & OP_RT_RA_MASK) == LIS_R2)) && - ((*(insn + 1) & OP_RT_RA_MASK) == ADDI_R2_R2)) - return (ssize_t)(insn + 2) - base; - else - return addr - base; -} -#else -#define get_offset(addr, base) (addr - base) -#endif - -ssize_t get_base_addr() { - size_t start, offset; - char buf[256]; - FILE *f; - - f = fopen("/proc/self/maps", "r"); - if (!f) - return -errno; - - while (fscanf(f, "%zx-%*x %s %zx %*[^\n]\n", - &start, buf, &offset) == 3) { - if (strcmp(buf, "r-xp") == 0) { - fclose(f); - return start - offset; - } - } - - fclose(f); - return -EINVAL; -} - void test_attach_probe(void) { int duration = 0; @@ -74,7 +15,7 @@ void test_attach_probe(void) if (CHECK(base_addr < 0, "get_base_addr", "failed to find base addr: %zd", base_addr)) return; - uprobe_offset = get_offset((size_t)&get_base_addr, base_addr); + uprobe_offset = get_uprobe_offset(&get_base_addr, base_addr); skel = test_attach_probe__open_and_load(); if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index 1bbd1d9..381dafc 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -136,3 +136,69 @@ void read_trace_pipe(void) } } } + +#if defined(__powerpc64__) && defined(_CALL_ELF) && _CALL_ELF == 2 + +#define OP_RT_RA_MASK 0xffff0000UL +#define LIS_R2 0x3c400000UL +#define ADDIS_R2_R12 0x3c4c0000UL +#define ADDI_R2_R2 0x38420000UL + +ssize_t get_uprobe_offset(const void *addr, ssize_t base) +{ + u32 *insn = (u32 *)(uintptr_t)addr; + + /* + * A PPC64 ABIv2 function may have a local and a global entry + * point. We need to use the local entry point when patching + * functions, so identify and step over the global entry point + * sequence. + * + * The global entry point sequence is always of the form: + * + * addis r2,r12,XXXX + * addi r2,r2,XXXX + * + * A linker optimisation may convert the addis to lis: + * + * lis r2,XXXX + * addi r2,r2,XXXX + */ + if ((((*insn & OP_RT_RA_MASK) == ADDIS_R2_R12) || + ((*insn & OP_RT_RA_MASK) == LIS_R2)) && + ((*(insn + 1) & OP_RT_RA_MASK) == ADDI_R2_R2)) + return (ssize_t)(insn + 2) - base; + else + return (uintptr_t)addr - base; +} + +#else + +ssize_t get_uprobe_offset(const void *addr, ssize_t base) +{ + return (uintptr_t)addr - base; +} + +#endif + +ssize_t get_base_addr(void) +{ + size_t start, offset; + char buf[256]; + FILE *f; + + f = fopen("/proc/self/maps", "r"); + if (!f) + return -errno; + + while (fscanf(f, "%zx-%*x %s %zx %*[^\n]\n", + &start, buf, &offset) == 3) { + if (strcmp(buf, "r-xp") == 0) { + fclose(f); + return start - offset; + } + } + + fclose(f); + return -EINVAL; +} diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h index f62fdef..3d9435b 100644 --- a/tools/testing/selftests/bpf/trace_helpers.h +++ b/tools/testing/selftests/bpf/trace_helpers.h @@ -18,4 +18,7 @@ int kallsyms_find(const char *sym, unsigned long long *addr); void read_trace_pipe(void); +ssize_t get_uprobe_offset(const void *addr, ssize_t base); +ssize_t get_base_addr(void); + #endif -- 2.7.4