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 <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210815070609.987780-14-andrii@kernel.org

diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c
index ec11e20d2b92b5692612dd15d950e32777baf95c..e40b41c44f8bd08c3e7e9a931bf724b340e0f7b7 100644 (file)
--- 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 1bbd1d9830c852b133ab164c3aa613e1986a7fa5..381dafce1d8fc4ccde8b760fbb1b01cac183d21a 100644 (file)
--- 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 f62fdef9e589c14cdf1b796adca00a015448f0b3..3d9435b3dd3b91dc941db848e685b77f43eb3885 100644 (file)
--- 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