c++tools: Fix memory leak
Commit Message
The allocated memory is not freed when returning early due to an error.
c++tools/ChangeLog:
* resolver.cc (module_resolver::read_tuple_file): Use unique_ptr
to ensure memory is freed before returning.
---
c++tools/resolver.cc | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
Comments
On 10/21/21 09:28, Jonathan Wakely wrote:
> The allocated memory is not freed when returning early due to an error.
>
> c++tools/ChangeLog:
>
> * resolver.cc (module_resolver::read_tuple_file): Use unique_ptr
> to ensure memory is freed before returning.
> ---
> c++tools/resolver.cc | 14 ++++++++------
> 1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/c++tools/resolver.cc b/c++tools/resolver.cc
> index 421fdaa55fe..d1b73a47778 100644
> --- a/c++tools/resolver.cc
> +++ b/c++tools/resolver.cc
> @@ -23,6 +23,7 @@ along with GCC; see the file COPYING3. If not see
> #include "resolver.h"
> // C++
> #include <algorithm>
> +#include <memory>
> // C
> #include <cstring>
> // OS
> @@ -114,10 +115,17 @@ module_resolver::read_tuple_file (int fd, char const *prefix, bool force)
> buffer = mmap (nullptr, stat.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
> if (buffer == MAP_FAILED)
> return -errno;
> + struct Deleter {
> + void operator()(void* p) const { munmap(p, size); }
> + size_t size;
> + };
> + std::unique_ptr<void, Deleter> guard(buffer, Deleter{(size_t)stat.st_size});
> #else
> buffer = xmalloc (stat.st_size);
> if (!buffer)
> return -errno;
> + struct Deleter { void operator()(void* p) const { free(p); } };
> + std::unique_ptr<void, Deleter> guard;
Don't you need to initialize guard from buffer?
> if (read (fd, buffer, stat.st_size) != stat.st_size)
> return -errno;
> #endif
> @@ -179,12 +187,6 @@ module_resolver::read_tuple_file (int fd, char const *prefix, bool force)
> }
> }
>
> -#if MAPPED_READING
> - munmap (buffer, stat.st_size);
> -#else
> - free (buffer);
> -#endif
> -
> return 0;
> }
>
>
@@ -23,6 +23,7 @@ along with GCC; see the file COPYING3. If not see
#include "resolver.h"
// C++
#include <algorithm>
+#include <memory>
// C
#include <cstring>
// OS
@@ -114,10 +115,17 @@ module_resolver::read_tuple_file (int fd, char const *prefix, bool force)
buffer = mmap (nullptr, stat.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (buffer == MAP_FAILED)
return -errno;
+ struct Deleter {
+ void operator()(void* p) const { munmap(p, size); }
+ size_t size;
+ };
+ std::unique_ptr<void, Deleter> guard(buffer, Deleter{(size_t)stat.st_size});
#else
buffer = xmalloc (stat.st_size);
if (!buffer)
return -errno;
+ struct Deleter { void operator()(void* p) const { free(p); } };
+ std::unique_ptr<void, Deleter> guard;
if (read (fd, buffer, stat.st_size) != stat.st_size)
return -errno;
#endif
@@ -179,12 +187,6 @@ module_resolver::read_tuple_file (int fd, char const *prefix, bool force)
}
}
-#if MAPPED_READING
- munmap (buffer, stat.st_size);
-#else
- free (buffer);
-#endif
-
return 0;
}