when building elf2dump with x86_64-w64-mingw32-gcc, fwrite is imported from
msvcrt.dll. However, the implementation of msvcrt.dll!fwrite is buggy:
it enters an infinite loop when the size of a single write exceeds 4GB.
This patch addresses the issue by splitting large physical memory
blocks into smaller chunks.
Signed-off-by: junjiehua <junjie...@tencent.com>
---
contrib/elf2dmp/main.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/contrib/elf2dmp/main.c b/contrib/elf2dmp/main.c
index d046a72ae6..1994553d95 100644
--- a/contrib/elf2dmp/main.c
+++ b/contrib/elf2dmp/main.c
@@ -23,6 +23,8 @@
#define INITIAL_MXCSR 0x1f80
#define MAX_NUMBER_OF_RUNS 42
+#define MAX_CHUNK_SIZE (128 * 1024 * 1024)
+
typedef struct idt_desc {
uint16_t offset1; /* offset bits 0..15 */
uint16_t selector;
@@ -434,13 +436,22 @@ static bool write_dump(struct pa_space *ps,
for (i = 0; i < ps->block_nr; i++) {
struct pa_block *b = &ps->block[i];
+ size_t offset = 0;
+ size_t chunk_size;
printf("Writing block #%zu/%zu of %"PRIu64" bytes to file...\n", i,
ps->block_nr, b->size);
- if (fwrite(b->addr, b->size, 1, dmp_file) != 1) {
- eprintf("Failed to write block\n");
- fclose(dmp_file);
- return false;
+
+ while (offset < b->size) {
+ chunk_size = (b->size - offset > MAX_CHUNK_SIZE)
+ ? MAX_CHUNK_SIZE
+ : (b->size - offset);
+ if (fwrite(b->addr + offset, chunk_size, 1, dmp_file) != 1) {
+ eprintf("Failed to write block\n");
+ fclose(dmp_file);
+ return false;
+ }
+ offset += chunk_size;
}
}
--
2.45.2
