Re: [PATCH 1/5] contrib/elf2dmp: Grow PDB URL buffer

[Akihiko Odaki]

On 2026/01/26 1:58, Philippe Mathieu-Daudé wrote:
On 25/1/26 07:42, Akihiko Odaki wrote:
The buffers used to construct a PDB URL overflow when the "age" property
is greater than 0xf, so grow it. This also simplifies the logic of the
URL construction to use one buffer instead of two to avoid the chore to
synchronize the sizes of two buffers.
Signed-off-by: Akihiko Odaki <od...@rsg.ci.i.u-tokyo.ac.jp>
---
  contrib/elf2dmp/main.c | 27 ++++++++++-----------------
  1 file changed, 10 insertions(+), 17 deletions(-)

diff --git a/contrib/elf2dmp/main.c b/contrib/elf2dmp/main.c
index d046a72ae67f..83ddc57dd9ee 100644
--- a/contrib/elf2dmp/main.c
+++ b/contrib/elf2dmp/main.c
@@ -494,18 +494,6 @@ static bool pe_check_pdb_name(uint64_t base, void 
*start_addr,
      return !strcmp(pdb_name, PDB_NAME);
  }
-static void pe_get_pdb_symstore_hash(OMFSignatureRSDS *rsds, char *hash)
-{
-    sprintf(hash, "%.08x%.04x%.04x%.02x%.02x", rsds->guid.a, rsds- 
>guid.b,
-            rsds->guid.c, rsds->guid.d[0], rsds->guid.d[1]);
-    hash += 20;
-    for (unsigned int i = 0; i < 6; i++, hash += 2) {
-        sprintf(hash, "%.02x", rsds->guid.e[i]);
-    }
-
-    sprintf(hash, "%.01x", rsds->age);
-}
-
  int main(int argc, char *argv[])
  {
      int err = 1;
@@ -517,9 +505,7 @@ int main(int argc, char *argv[])
      uint64_t KernBase;
      void *nt_start_addr = NULL;
      WinDumpHeader64 header;
-    char pdb_hash[34];
-    char pdb_url[] = SYM_URL_BASE PDB_NAME
-        "/0123456789ABCDEF0123456789ABCDEFx/" PDB_NAME;
+    char pdb_url[sizeof(SYM_URL_BASE PDB_NAME PDB_NAME) + 42];
      struct pdb_reader pdb;
      uint64_t KdDebuggerDataBlock;
      KDDEBUGGER_DATA64 *kdbg;
@@ -583,9 +569,16 @@ int main(int argc, char *argv[])
      printf("KernBase = 0x%016"PRIx64", signature is \'%.2s\'\n", 
KernBase,
              (char *)nt_start_addr);
-    pe_get_pdb_symstore_hash(&rsds, pdb_hash);

I'd rather use g_autofree + g_strdup_printf and drop the _NAME definitions.

g_autofree + g_strdup_printf will work. PDB_NAME is still useful because 
somehow it is repeated twice in the URL.


+    sprintf(pdb_url,
+            "%s%.08x%.04x%.04x"
+            "%.02x%.02x"
+            "%.02x%.02x%.02x%.02x%.02x%.02x"
+            "%.01x%s",
+            SYM_URL_BASE PDB_NAME "/", rsds.guid.a, rsds.guid.b, 
rsds.guid.c,
+            rsds.guid.d[0], rsds.guid.d[1],
+            rsds.guid.e[0], rsds.guid.e[1], rsds.guid.e[2], 
rsds.guid.e[3], rsds.guid.e[4], rsds.guid.e[5],
+            rsds.age, "/" PDB_NAME);
-    sprintf(pdb_url, "%s%s/%s/%s", SYM_URL_BASE, PDB_NAME, pdb_hash, 
PDB_NAME);
      printf("PDB URL is %s\n", pdb_url);
      if (!download_url(PDB_NAME, pdb_url)) {