Merge pull request #252 from P403n1x87/refactor/linux-proc-maps

refactor(linux): proc maps parsing

src/linux/proc/exe.h

@@ -0,0 +1,57 @@
+// This file is part of "austin" which is released under GPL.
+//
+// See file LICENCE or go to http://www.gnu.org/licenses/ for full license
+// details.
+//
+// Austin is a Python frame stack sampler for CPython.
+//
+// Copyright (c) 2018-2021 Gabriele N. Tornetta <[email protected]>.
+// All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#pragma once
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "../../error.h"
+#include "../../hints.h"
+
+
+#define DELETED_SUFFIX " (deleted)"
+
+
+// ----------------------------------------------------------------------------
+static int
+proc_exe_readlink(pid_t pid, char * dest, ssize_t size) {
+    char file_name[32];
+
+    sprintf(file_name, "/proc/%d/exe", pid);
+
+    if (readlink(file_name, dest, size) == -1) {
+        log_e("Cannot readlink %s", file_name);
+        FAIL;  // cppcheck-suppress [resourceLeak]
+    }
+
+    // Handle deleted files
+    char * suffix = strstr(dest, DELETED_SUFFIX);
+    if (isvalid(suffix)) {
+        *suffix = '\0';
+    }
+
+    SUCCESS;
+}

src/linux/proc/maps.h

@@ -0,0 +1,171 @@
+// This file is part of "austin" which is released under GPL.
+//
+// See file LICENCE or go to http://www.gnu.org/licenses/ for full license
+// details.
+//
+// Austin is a Python frame stack sampler for CPython.
+//
+// Copyright (c) 2018-2021 Gabriele N. Tornetta <[email protected]>.
+// All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#pragma once
+
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "../../error.h"
+#include "../../resources.h"
+#include "../common.h"
+
+// ----------------------------------------------------------------------------
+
+typedef struct _proc_map {
+    void             * address;
+    size_t             size;
+    uint8_t            perms;
+    char             * pathname;
+
+    struct _proc_map * next;
+} proc_map_t;
+
+
+#define PERMS_READ  (1 << 0)
+#define PERMS_WRITE (1 << 1)
+#define PERMS_EXEC  (1 << 2)
+
+
+#define PROC_MAP_ITER(proc_maps, map) \
+    for (proc_map_t * map = proc_maps; isvalid(map); map = map->next)
+
+
+// ----------------------------------------------------------------------------
+static inline proc_map_t *
+proc_map_new(pid_t pid) {
+    cu_char    * line = NULL;
+    size_t       len = 0;
+    char         pathname[1024] = { 0 };
+    char         perms[5] = { 0 };
+    proc_map_t * head = NULL;
+    proc_map_t * curr = NULL;
+    proc_map_t * next = NULL;
+
+    cu_FILE* fp = _procfs(pid, "maps");
+    if (fp == NULL) {
+        switch (errno) {
+        case EACCES:  // Needs elevated privileges
+            set_error(EPROCPERM);
+            break;
+        case ENOENT:  // Invalid pid
+            set_error(EPROCNPID);
+            break;
+        default:
+            set_error(EPROCVM);
+        }
+        return NULL;
+    }
+
+    while (getline(&line, &len, fp) != -1) {
+        ssize_t lower, upper;
+
+        int has_pathname = sscanf(line, ADDR_FMT "-" ADDR_FMT " %s %*x %*x:%*x %*x %s\n",
+            &lower, &upper, // Map bounds
+            perms,          // Permissions
+            pathname        // Binary path
+        ) - 3; // We expect between 3 and 4 matches. We skip offset, dev and inode
+
+        if (has_pathname < 0) {
+            // Too few columns. This shouldn't happen but we skip this case anyway.
+            continue;
+        }
+        if (has_pathname && pathname[0] == '[') {
+            // Skip kernel memory maps
+            continue;
+        }
+
+        next = (proc_map_t*)calloc(1, sizeof(proc_map_t));
+        if (!isvalid(next)) {
+            log_ie("Cannot allocate memory for proc_map_t");
+            set_error(EPROC);
+            break;
+        }
+        if (!isvalid(head)) {
+            head = next;
+        }
+        else {
+            curr->next = next;
+        }
+        curr = next;
+
+        curr->address = (void*)lower;
+        curr->size = upper - lower;
+        curr->perms = 0;
+        if (perms[0] == 'r') curr->perms |= PERMS_READ;
+        if (perms[1] == 'w') curr->perms |= PERMS_WRITE;
+        if (perms[2] == 'x') curr->perms |= PERMS_EXEC;
+        curr->pathname = has_pathname ? strdup(pathname) : NULL;
+    }
+
+    return head;
+}
+
+
+// ----------------------------------------------------------------------------
+static inline proc_map_t*
+proc_map__first(proc_map_t* self, char * pathname) {
+    if (!isvalid(self) || !isvalid(pathname))
+        return NULL;
+
+    PROC_MAP_ITER(self, map) {
+        if (isvalid(map->pathname) && strcmp(map->pathname, pathname) == 0)
+            return map;
+    }
+
+    return NULL;
+}
+
+
+// ----------------------------------------------------------------------------
+static inline proc_map_t*
+proc_map__first_submatch(proc_map_t* self, char * needle) {
+    if (!isvalid(self) || !isvalid(needle))
+        return NULL;
+
+    PROC_MAP_ITER(self, map) {
+        if (isvalid(map->pathname) && isvalid(strstr(map->pathname, needle))) {
+            return map;
+        }
+    }
+
+    return NULL;
+}
+
+
+// ----------------------------------------------------------------------------
+static inline void
+proc_map__destroy(proc_map_t * self) {
+    if (!isvalid(self))
+        return;
+
+    proc_map__destroy(self->next);
+
+    sfree(self->pathname);
+
+    free(self);
+}
+
+CLEANUP_TYPE(proc_map_t, proc_map__destroy);
+#define cu_proc_map_t __attribute__((cleanup(proc_map__destroyt))) proc_map_t