From: Andrii Nakryiko <andrii@kernel.org>
To: <bpf@vger.kernel.org>, <ast@kernel.org>, <daniel@iogearbox.net>
Cc: <andrii@kernel.org>, <kernel-team@fb.com>,
Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH v4 bpf-next 13/14] selftests/bpf: extract uprobe-related helpers into trace_helpers.{c,h}
Date: Tue, 10 Aug 2021 14:36:33 -0700 [thread overview]
Message-ID: <20210810213634.272111-14-andrii@kernel.org> (raw)
In-Reply-To: <20210810213634.272111-1-andrii@kernel.org>
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 <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 ec11e20d2b92..e40b41c44f8b 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 <test_progs.h>
#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 1bbd1d9830c8..381dafce1d8f 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 f62fdef9e589..3d9435b3dd3b 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
--
2.30.2
next prev parent reply other threads:[~2021-08-10 21:37 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-10 21:36 [PATCH v4 bpf-next 00/14] BPF perf link and user-provided bpf_cookie Andrii Nakryiko
2021-08-10 21:36 ` [PATCH v4 bpf-next 01/14] bpf: refactor BPF_PROG_RUN into a function Andrii Nakryiko
2021-08-10 21:36 ` [PATCH v4 bpf-next 02/14] bpf: refactor BPF_PROG_RUN_ARRAY family of macros into functions Andrii Nakryiko
2021-08-10 21:36 ` [PATCH v4 bpf-next 03/14] bpf: refactor perf_event_set_bpf_prog() to use struct bpf_prog input Andrii Nakryiko
2021-08-10 21:36 ` [PATCH v4 bpf-next 04/14] bpf: implement minimal BPF perf link Andrii Nakryiko
2021-08-10 21:36 ` [PATCH v4 bpf-next 05/14] bpf: allow to specify user-provided bpf_cookie for BPF perf links Andrii Nakryiko
2021-08-10 21:36 ` [PATCH v4 bpf-next 06/14] bpf: add bpf_get_attach_cookie() BPF helper to access bpf_cookie value Andrii Nakryiko
2021-08-10 21:36 ` [PATCH v4 bpf-next 07/14] libbpf: re-build libbpf.so when libbpf.map changes Andrii Nakryiko
2021-08-10 21:36 ` [PATCH v4 bpf-next 08/14] libbpf: remove unused bpf_link's destroy operation, but add dealloc Andrii Nakryiko
2021-08-10 21:36 ` [PATCH v4 bpf-next 09/14] libbpf: use BPF perf link when supported by kernel Andrii Nakryiko
2021-08-10 21:36 ` [PATCH v4 bpf-next 10/14] libbpf: add bpf_cookie support to bpf_link_create() API Andrii Nakryiko
2021-08-10 21:36 ` [PATCH v4 bpf-next 11/14] libbpf: add bpf_cookie to perf_event, kprobe, uprobe, and tp attach APIs Andrii Nakryiko
2021-08-10 21:36 ` [PATCH v4 bpf-next 12/14] selftests/bpf: test low-level perf BPF link API Andrii Nakryiko
2021-08-10 21:36 ` Andrii Nakryiko [this message]
2021-08-10 21:36 ` [PATCH v4 bpf-next 14/14] selftests/bpf: add bpf_cookie selftests for high-level APIs Andrii Nakryiko
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