udev: fix codesonar warnings

[thirdparty/systemd.git] / src / journal / mmap-cache.c

diff --git a/src/journal/mmap-cache.c b/src/journal/mmap-cache.c
index 3e076f8fea31ed2d0191271b13ded0aa09062b0e..9eb3e1a62625d5510f2480c8e7bff55e61ee7ba2 100644 (file)
--- a/src/journal/mmap-cache.c
+++ b/src/journal/mmap-cache.c
@@ -1,35 +1,19 @@
-/***
-  This file is part of systemd.
-
-  Copyright 2012 Lennart Poettering
-
-  systemd is free software; you can redistribute it and/or modify it
-  under the terms of the GNU Lesser General Public License as published by
-  the Free Software Foundation; either version 2.1 of the License, or
-  (at your option) any later version.
-
-  systemd 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
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public License
-  along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
+/* SPDX-License-Identifier: LGPL-2.1+ */
 
 #include <errno.h>
 #include <stdlib.h>
 #include <sys/mman.h>
 
 #include "alloc-util.h"
+#include "errno-util.h"
 #include "fd-util.h"
 #include "hashmap.h"
 #include "list.h"
 #include "log.h"
 #include "macro.h"
+#include "memory-util.h"
 #include "mmap-cache.h"
 #include "sigbus.h"
-#include "util.h"
 
 typedef struct Window Window;
 typedef struct Context Context;
@@ -70,7 +54,7 @@ struct MMapFileDescriptor {
 };
 
 struct MMapCache {
-        int n_ref;
+        unsigned n_ref;
         unsigned n_windows;
 
         unsigned n_hit, n_missed;
@@ -84,7 +68,7 @@ struct MMapCache {
 
 #define WINDOWS_MIN 64
 
-#ifdef ENABLE_DEBUG_MMAP_CACHE
+#if ENABLE_DEBUG_MMAP_CACHE
 /* Tiny windows increase mmap activity and the chance of exposing unsafe use. */
 # define WINDOW_SIZE (page_size())
 #else
@@ -102,14 +86,6 @@ MMapCache* mmap_cache_new(void) {
         return m;
 }
 
-MMapCache* mmap_cache_ref(MMapCache *m) {
-        assert(m);
-        assert(m->n_ref > 0);
-
-        m->n_ref++;
-        return m;
-}
-
 static void window_unlink(Window *w) {
         Context *c;
 
@@ -157,7 +133,7 @@ static void window_free(Window *w) {
         free(w);
 }
 
-_pure_ static inline bool window_matches(Window *w, int prot, uint64_t offset, size_t size) {
+_pure_ static bool window_matches(Window *w, int prot, uint64_t offset, size_t size) {
         assert(w);
         assert(size > 0);
 
@@ -186,7 +162,7 @@ static Window *window_add(MMapCache *m, MMapFileDescriptor *f, int prot, bool ke
         if (!m->last_unused || m->n_windows <= WINDOWS_MIN) {
 
                 /* Allocate a new window */
-                w = new0(Window, 1);
+                w = new(Window, 1);
                 if (!w)
                         return NULL;
                 m->n_windows++;
@@ -195,16 +171,17 @@ static Window *window_add(MMapCache *m, MMapFileDescriptor *f, int prot, bool ke
                 /* Reuse an existing one */
                 w = m->last_unused;
                 window_unlink(w);
-                zero(*w);
         }
 
-        w->cache = m;
-        w->fd = f;
-        w->prot = prot;
-        w->keep_always = keep_always;
-        w->offset = offset;
-        w->size = size;
-        w->ptr = ptr;
+        *w = (Window) {
+                .cache = m,
+                .fd = f,
+                .prot = prot,
+                .keep_always = keep_always,
+                .offset = offset,
+                .size = size,
+                .ptr = ptr,
+        };
 
         LIST_PREPEND(by_fd, f->windows, w);
 
@@ -219,13 +196,12 @@ static void context_detach_window(Context *c) {
         if (!c->window)
                 return;
 
-        w = c->window;
-        c->window = NULL;
+        w = TAKE_PTR(c->window);
         LIST_REMOVE(by_window, w->contexts, c);
 
         if (!w->contexts && !w->keep_always) {
                 /* Not used anymore? */
-#ifdef ENABLE_DEBUG_MMAP_CACHE
+#if ENABLE_DEBUG_MMAP_CACHE
                 /* Unmap unused windows immediately to expose use-after-unmap
                  * by SIGSEGV. */
                 window_free(w);
@@ -296,7 +272,7 @@ static void context_free(Context *c) {
         free(c);
 }
 
-static void mmap_cache_free(MMapCache *m) {
+static MMapCache *mmap_cache_free(MMapCache *m) {
         int i;
 
         assert(m);
@@ -310,22 +286,10 @@ static void mmap_cache_free(MMapCache *m) {
         while (m->unused)
                 window_free(m->unused);
 
-        free(m);
+        return mfree(m);
 }
 
-MMapCache* mmap_cache_unref(MMapCache *m) {
-
-        if (!m)
-                return NULL;
-
-        assert(m->n_ref > 0);
-
-        m->n_ref--;
-        if (m->n_ref == 0)
-                mmap_cache_free(m);
-
-        return NULL;
-}
+DEFINE_TRIVIAL_REF_UNREF_FUNC(MMapCache, mmap_cache, mmap_cache_free);
 
 static int make_room(MMapCache *m) {
         assert(m);
@@ -345,7 +309,8 @@ static int try_context(
                 bool keep_always,
                 uint64_t offset,
                 size_t size,
-                void **ret) {
+                void **ret,
+                size_t *ret_size) {
 
         Context *c;
 
@@ -377,6 +342,9 @@ static int try_context(
         c->window->keep_always = c->window->keep_always || keep_always;
 
         *ret = (uint8_t*) c->window->ptr + (offset - c->window->offset);
+        if (ret_size)
+                *ret_size = c->window->size - (offset - c->window->offset);
+
         return 1;
 }
 
@@ -388,7 +356,8 @@ static int find_mmap(
                 bool keep_always,
                 uint64_t offset,
                 size_t size,
-                void **ret) {
+                void **ret,
+                size_t *ret_size) {
 
         Window *w;
         Context *c;
@@ -416,6 +385,9 @@ static int find_mmap(
         w->keep_always = w->keep_always || keep_always;
 
         *ret = (uint8_t*) w->ptr + (offset - w->offset);
+        if (ret_size)
+                *ret_size = w->size - (offset - w->offset);
+
         return 1;
 }
 
@@ -455,7 +427,8 @@ static int add_mmap(
                 uint64_t offset,
                 size_t size,
                 struct stat *st,
-                void **ret) {
+                void **ret,
+                size_t *ret_size) {
 
         uint64_t woffset, wsize;
         Context *c;
@@ -513,6 +486,9 @@ static int add_mmap(
         context_attach_window(c, w);
 
         *ret = (uint8_t*) w->ptr + (offset - w->offset);
+        if (ret_size)
+                *ret_size = w->size - (offset - w->offset);
+
         return 1;
 
 outofmem:
@@ -529,7 +505,8 @@ int mmap_cache_get(
                 uint64_t offset,
                 size_t size,
                 struct stat *st,
-                void **ret) {
+                void **ret,
+                size_t *ret_size) {
 
         int r;
 
@@ -541,14 +518,14 @@ int mmap_cache_get(
         assert(context < MMAP_CACHE_MAX_CONTEXTS);
 
         /* Check whether the current context is the right one already */
-        r = try_context(m, f, prot, context, keep_always, offset, size, ret);
+        r = try_context(m, f, prot, context, keep_always, offset, size, ret, ret_size);
         if (r != 0) {
                 m->n_hit++;
                 return r;
         }
 
         /* Search for a matching mmap */
-        r = find_mmap(m, f, prot, context, keep_always, offset, size, ret);
+        r = find_mmap(m, f, prot, context, keep_always, offset, size, ret, ret_size);
         if (r != 0) {
                 m->n_hit++;
                 return r;
@@ -557,7 +534,7 @@ int mmap_cache_get(
         m->n_missed++;
 
         /* Create a new mmap */
-        return add_mmap(m, f, prot, context, keep_always, offset, size, st, ret);
+        return add_mmap(m, f, prot, context, keep_always, offset, size, st, ret, ret_size);
 }
 
 unsigned mmap_cache_get_hit(MMapCache *m) {