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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2017-09-18 09:26:00 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2017-09-25 18:04:22 -0700
commit5f9f31ad129d97e6fc548954c9b97e27dd332600 (patch)
treeb7f30d51192c046e0d23b6a04346d6549c9cb24f /include/scratch_buffer.h
parentccf970c7a77e86f4f5ef8ecc5e637114b1c0136a (diff)
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scratch_buffer: use union for internal buffer
Problem reported by Florian Weimer [1] and solution suggested by Andreas Schwab [2]. It also set the same buffer size independent of architecture max_align_t size. Checked on x86_64-linux-gnu and i686-linux-gnu. * lib/malloc/scratch_buffer.h (struct scratch_buffer): Use an union instead of a max_align_t array for __space, so that __space is the same size on all platforms. * malloc/scratch_buffer_grow_preserve.c (__libc_scratch_buffer_grow_preserve): Likewise. [1] https://sourceware.org/ml/libc-alpha/2017-09/msg00693.html [2] https://sourceware.org/ml/libc-alpha/2017-09/msg00695.html
Diffstat (limited to 'include/scratch_buffer.h')
-rw-r--r--include/scratch_buffer.h6
1 files changed, 3 insertions, 3 deletions
diff --git a/include/scratch_buffer.h b/include/scratch_buffer.h
index bb04662..b19b166 100644
--- a/include/scratch_buffer.h
+++ b/include/scratch_buffer.h
@@ -66,7 +66,7 @@
struct scratch_buffer {
void *data; /* Pointer to the beginning of the scratch area. */
size_t length; /* Allocated space at the data pointer, in bytes. */
- max_align_t __space[(1023 + sizeof (max_align_t)) / sizeof (max_align_t)];
+ union { max_align_t __align; char __c[1024]; } __space;
};
/* Initializes *BUFFER so that BUFFER->data points to BUFFER->__space
@@ -74,7 +74,7 @@ struct scratch_buffer {
static inline void
scratch_buffer_init (struct scratch_buffer *buffer)
{
- buffer->data = buffer->__space;
+ buffer->data = buffer->__space.__c;
buffer->length = sizeof (buffer->__space);
}
@@ -82,7 +82,7 @@ scratch_buffer_init (struct scratch_buffer *buffer)
static inline void
scratch_buffer_free (struct scratch_buffer *buffer)
{
- if (buffer->data != buffer->__space)
+ if (buffer->data != buffer->__space.__c)
free (buffer->data);
}