perf llvm: Use realpath to canonicalize paths

To kill the last user of make_nonrelative_path(), that gets ditched,
one more panicking function killed.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-3hu56rvyh4q5gxogovb6ko8a@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

4 files changed, 12 insertions, 44 deletions

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index eea25e2424e9..da48fd843438 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -1,4 +1,3 @@
-libperf-y += abspath.o
 libperf-y += alias.o
 libperf-y += annotate.o
 libperf-y += build-id.o
diff --git a/tools/perf/util/abspath.c b/tools/perf/util/abspath.c
deleted file mode 100644
index 0e76affe9c36..000000000000
--- a/tools/perf/util/abspath.c
+++ /dev/null
@@ -1,37 +0,0 @@
-#include "cache.h"
-
-static const char *get_pwd_cwd(void)
-{
-        static char cwd[PATH_MAX + 1];
-        char *pwd;
-        struct stat cwd_stat, pwd_stat;
-        if (getcwd(cwd, PATH_MAX) == NULL)
-                return NULL;
-        pwd = getenv("PWD");
-        if (pwd && strcmp(pwd, cwd)) {
-                stat(cwd, &cwd_stat);
-                if (!stat(pwd, &pwd_stat) &&
-                    pwd_stat.st_dev == cwd_stat.st_dev &&
-                    pwd_stat.st_ino == cwd_stat.st_ino) {
-                        strlcpy(cwd, pwd, PATH_MAX);
-                }
-        }
-        return cwd;
-}
-
-const char *make_nonrelative_path(const char *path)
-{
-        static char buf[PATH_MAX + 1];
-
-        if (is_absolute_path(path)) {
-                if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
-                        die("Too long path: %.*s", 60, path);
-        } else {
-                const char *cwd = get_pwd_cwd();
-                if (!cwd)
-                        die("Cannot determine the current working directory");
-                if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX)
-                        die("Too long path: %.*s", 60, path);
-        }
-        return buf;
-}
diff --git a/tools/perf/util/cache.h b/tools/perf/util/cache.h
index da322bea56f7..1f5a93c2c9a2 100644
--- a/tools/perf/util/cache.h
+++ b/tools/perf/util/cache.h
@@ -64,7 +64,6 @@ static inline int is_absolute_path(const char *path)
         return path[0] == '/';
 }
 
-const char *make_nonrelative_path(const char *path);
 char *strip_path_suffix(const char *path, const char *suffix);
 
 char *mkpath(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c
index 00724d496d38..aab855f491ca 100644
--- a/tools/perf/util/llvm-utils.c
+++ b/tools/perf/util/llvm-utils.c
@@ -3,11 +3,11 @@
  * Copyright (C) 2015, Huawei Inc.
  */
 
+#include <limits.h>
 #include <stdio.h>
-#include "util.h"
+#include <stdlib.h>
 #include "debug.h"
 #include "llvm-utils.h"
-#include "cache.h"
 
 #define CLANG_BPF_CMD_DEFAULT_TEMPLATE                          \
                 "$CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS "\
@@ -334,10 +334,18 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
         unsigned int kernel_version;
         char linux_version_code_str[64];
         const char *clang_opt = llvm_param.clang_opt;
-        char clang_path[PATH_MAX], nr_cpus_avail_str[64];
+        char clang_path[PATH_MAX], abspath[PATH_MAX], nr_cpus_avail_str[64];
+        char serr[STRERR_BUFSIZE];
         char *kbuild_dir = NULL, *kbuild_include_opts = NULL;
         const char *template = llvm_param.clang_bpf_cmd_template;
 
+        if (path[0] != '-' && realpath(path, abspath) == NULL) {
+                err = errno;
+                pr_err("ERROR: problems with path %s: %s\n",
+                       path, strerror_r(err, serr, sizeof(serr)));
+                return -err;
+        }
+
         if (!template)
                 template = CLANG_BPF_CMD_DEFAULT_TEMPLATE;
 
@@ -387,8 +395,7 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
          * stdin to be source file (testing).
          */
         force_set_env("CLANG_SOURCE",
-                      (path[0] == '-') ? path :
-                      make_nonrelative_path(path));
+                      (path[0] == '-') ? path : abspath);
 
         pr_debug("llvm compiling command template: %s\n", template);
         err = read_from_pipe(template, &obj_buf, &obj_buf_sz);