[PATCH] dbghelp: use a buffer ring instead of single buffer for fetch_buffer
Eric Pouech
eric.pouech at gmail.com
Thu Jul 22 02:38:23 CDT 2021
as reported by Alistair, SymGetLineFromAddrW64 requires at least two buffers
I suggest using this patch instead of Alistair's, because:
- it doesn't duplicate internal lookup functions between A and W versions
- it's more robust against future use of fetch_buffer
Signed-off-by: Eric Pouech <eric.pouech at gmail.com>
---
dlls/dbghelp/dbghelp.c | 18 ++++++++++++------
dlls/dbghelp/dbghelp_private.h | 11 +++++++++--
2 files changed, 21 insertions(+), 8 deletions(-)
diff --git a/dlls/dbghelp/dbghelp.c b/dlls/dbghelp/dbghelp.c
index 00d7b61fbd8..af8cf17741c 100644
--- a/dlls/dbghelp/dbghelp.c
+++ b/dlls/dbghelp/dbghelp.c
@@ -118,15 +118,21 @@ BOOL validate_addr64(DWORD64 addr)
*/
void* fetch_buffer(struct process* pcs, unsigned size)
{
- if (size > pcs->buffer_size)
+ struct process_buffer* pb = &pcs->buffers[pcs->buffers_index];
+
+ if (size > pb->size)
{
- if (pcs->buffer)
- pcs->buffer = HeapReAlloc(GetProcessHeap(), 0, pcs->buffer, size);
+ void* new;
+ if (pb->ptr)
+ new = HeapReAlloc(GetProcessHeap(), 0, pb->ptr, size);
else
- pcs->buffer = HeapAlloc(GetProcessHeap(), 0, size);
- pcs->buffer_size = (pcs->buffer) ? size : 0;
+ new = HeapAlloc(GetProcessHeap(), 0, size);
+ if (!new) return NULL;
+ pb->size = size;
+ pb->ptr = new;
}
- return pcs->buffer;
+ pcs->buffers_index = (pcs->buffers_index + 1) % ARRAY_SIZE(pcs->buffers);
+ return pb->ptr;
}
const char* wine_dbgstr_addr(const ADDRESS64* addr)
diff --git a/dlls/dbghelp/dbghelp_private.h b/dlls/dbghelp/dbghelp_private.h
index 3415fc1557c..cc74d0c1edc 100644
--- a/dlls/dbghelp/dbghelp_private.h
+++ b/dlls/dbghelp/dbghelp_private.h
@@ -397,6 +397,12 @@ struct loader_ops
BOOL (*fetch_file_info)(struct process* process, const WCHAR* name, ULONG_PTR load_addr, DWORD_PTR* base, DWORD* size, DWORD* checksum);
};
+struct process_buffer
+{
+ unsigned size;
+ void* ptr;
+};
+
struct process
{
struct process* next;
@@ -415,8 +421,9 @@ struct process
IMAGEHLP_STACK_FRAME ctx_frame;
- unsigned buffer_size;
- void* buffer;
+ /* buffer:s ring */
+ struct process_buffer buffers[2];
+ unsigned buffers_index;
BOOL is_64bit;
};
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