On Mon, Dec 28, 2009 at 09:20:20PM +0100, Aurelien Jarno wrote:
> 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 <aurel...@aurel32.net>
I didn't know, you live and learn. FWIW
Acked-by: Michael S. Tsirkin <m...@redhat.com>
BTW, which systems implement this according to C99? glibc seems to do
free(non_null) on fedora 11.
> ---
> 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
>
>
