Re: [Qemu-devel] [PATCH] qemu-img: use the heap instead of the huge stack array for win32

[Anthony Liguori]

On 02/08/2010 02:20 AM, TeLeMan wrote:

The default stack size of PE is 1MB on win32 and IO_BUF_SIZE in
img_convert()&  img_rebase() is 2MB, so qemu-img will crash when doing
"convert"&  "rebase" on win32.
Although we can improve the stack size of PE to resolve it, I think we
should avoid using the huge stack variables.

Signed-off-by: TeLeMan<gele...@gmail.com>

Applied.  Thanks.

Regards,

Anthony Liguori

---

  qemu-img.c |   14 +++++++++++---
  1 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/qemu-img.c b/qemu-img.c
index bbfeea1..9994b3d 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -571,7 +571,7 @@ static int img_convert(int argc, char **argv)
      BlockDriverState **bs, *out_bs;
      int64_t total_sectors, nb_sectors, sector_num, bs_offset;
      uint64_t bs_sectors;
-    uint8_t buf[IO_BUF_SIZE];
+    uint8_t * buf;
      const uint8_t *buf1;
      BlockDriverInfo bdi;
      QEMUOptionParameter *param = NULL;
@@ -690,6 +690,7 @@ static int img_convert(int argc, char **argv)
      bs_i = 0;
      bs_offset = 0;
      bdrv_get_geometry(bs[0],&bs_sectors);
+    buf = qemu_malloc(IO_BUF_SIZE);

      if (flags&  BLOCK_FLAG_COMPRESS) {
          if (bdrv_get_info(out_bs,&bdi)<  0)
@@ -822,6 +823,7 @@ static int img_convert(int argc, char **argv)
              }
          }
      }
+    qemu_free(buf);
      bdrv_delete(out_bs);
      for (bs_i = 0; bs_i<  bs_n; bs_i++)
          bdrv_delete(bs[bs_i]);
@@ -1178,8 +1180,11 @@ static int img_rebase(int argc, char **argv)
          uint64_t num_sectors;
          uint64_t sector;
          int n, n1;
-        uint8_t buf_old[IO_BUF_SIZE];
-        uint8_t buf_new[IO_BUF_SIZE];
+        uint8_t * buf_old;
+        uint8_t * buf_new;
+
+        buf_old = qemu_malloc(IO_BUF_SIZE);
+        buf_new = qemu_malloc(IO_BUF_SIZE);

          bdrv_get_geometry(bs,&num_sectors);

@@ -1226,6 +1231,9 @@ static int img_rebase(int argc, char **argv)
                  written += pnum;
              }
          }
+
+        qemu_free(buf_old);
+        qemu_free(buf_new);
      }

      /*