* [PATCH] c++tools: Fix memory leak
@ 2021-10-21 13:28 Jonathan Wakely
2021-10-21 19:38 ` Jason Merrill
0 siblings, 1 reply; 4+ messages in thread
From: Jonathan Wakely @ 2021-10-21 13:28 UTC (permalink / raw)
To: libstdc++, gcc-patches; +Cc: Jason Merrill
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;
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;
}
--
2.31.1
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] c++tools: Fix memory leak
2021-10-21 13:28 [PATCH] c++tools: Fix memory leak Jonathan Wakely
@ 2021-10-21 19:38 ` Jason Merrill
2021-10-21 21:34 ` [PATCH v2] " Jonathan Wakely
0 siblings, 1 reply; 4+ messages in thread
From: Jason Merrill @ 2021-10-21 19:38 UTC (permalink / raw)
To: Jonathan Wakely, libstdc++, gcc-patches
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;
> }
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH v2] c++tools: Fix memory leak
2021-10-21 19:38 ` Jason Merrill
@ 2021-10-21 21:34 ` Jonathan Wakely
2021-10-26 14:19 ` Jason Merrill
0 siblings, 1 reply; 4+ messages in thread
From: Jonathan Wakely @ 2021-10-21 21:34 UTC (permalink / raw)
To: Jason Merrill; +Cc: libstdc++, gcc Patches
[-- Attachment #1: Type: text/plain, Size: 402 bytes --]
On Thu, 21 Oct 2021 at 20:38, Jason Merrill wrote:
> On 10/21/21 09:28, Jonathan Wakely wrote:
> > #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?
>
Oops, yes! Updated patch attached.
[-- Attachment #2: patch.txt --]
[-- Type: text/plain, Size: 1622 bytes --]
commit b280f6b5b4339586446eec99e49074e091c27ea5
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Thu Oct 21 22:32:23 2021
c++tools: Fix memory leak
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.
diff --git a/c++tools/resolver.cc b/c++tools/resolver.cc
index 421fdaa55fe..a1837b3ee10 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(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;
}
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v2] c++tools: Fix memory leak
2021-10-21 21:34 ` [PATCH v2] " Jonathan Wakely
@ 2021-10-26 14:19 ` Jason Merrill
0 siblings, 0 replies; 4+ messages in thread
From: Jason Merrill @ 2021-10-26 14:19 UTC (permalink / raw)
To: Jonathan Wakely; +Cc: libstdc++, gcc Patches
On 10/21/21 17:34, Jonathan Wakely wrote:
> On Thu, 21 Oct 2021 at 20:38, Jason Merrill wrote:
>
> On 10/21/21 09:28, Jonathan Wakely wrote:
> > #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?
>
>
> Oops, yes! Updated patch attached.
OK, thanks.
Jason
^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-10-21 13:28 [PATCH] c++tools: Fix memory leak Jonathan Wakely
2021-10-21 19:38 ` Jason Merrill
2021-10-21 21:34 ` [PATCH v2] " Jonathan Wakely
2021-10-26 14:19 ` Jason Merrill
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