[Qemu-devel] [PATCH v2] loader: don't call realloc(non_null, 0) when no symbols are present

[Aurelien Jarno]

According to C99, realloc(non_null, 0) != free(non_null), that's why
it is forbidden in QEMU.

When there are no symbols, nsyms equals to 0. Free the syms structure
and set it to NULL instead of reallocating it with a size of 0.

This fixes -kernel with stripped kernels.

Signed-off-by: Aurelien Jarno <address@hidden>
---
 hw/elf_ops.h |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/hw/elf_ops.h b/hw/elf_ops.h
index 6093dea..d0811ca 100644
--- a/hw/elf_ops.h
+++ b/hw/elf_ops.h
@@ -149,9 +149,14 @@ static int glue(load_symbols, SZ)(struct elfhdr *ehdr, int 
fd, int must_swab,
         }
         i++;
     }
-    syms = qemu_realloc(syms, nsyms * sizeof(*syms));
+    if (nsyms) {
+        syms = qemu_realloc(syms, nsyms * sizeof(*syms));
 
-    qsort(syms, nsyms, sizeof(*syms), glue(symcmp, SZ));
+        qsort(syms, nsyms, sizeof(*syms), glue(symcmp, SZ));
+    } else {
+        free(syms);
+        syms = NULL;
+    }
 
     /* String table */
     if (symtab->sh_link >= ehdr->e_shnum)
-- 
1.6.5.3