| Message ID | 20091228202020.GB4139@volta.aurel32.net |
|---|---|
| State | New |
| Headers | show |
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 <aurelien@aurel32.net> I didn't know, you live and learn. FWIW Acked-by: Michael S. Tsirkin <mst@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 > >
On Tue, Dec 29, 2009 at 05:36:40PM +0200, Michael S. Tsirkin wrote: > 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 <aurelien@aurel32.net> > > I didn't know, you live and learn. FWIW Can you please stop being annoying about that? I submit non-trivial patches like this one before committing them. This is nothing new.
On Tue, Dec 29, 2009 at 05:26:50PM +0100, Aurelien Jarno wrote: > On Tue, Dec 29, 2009 at 05:36:40PM +0200, Michael S. Tsirkin wrote: > > 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 <aurelien@aurel32.net> > > > > I didn't know, you live and learn. FWIW > > Can you please stop being annoying about that? I submit non-trivial > patches like this one before committing them. This is nothing new. Oh, this is a misunderstanding, sorry. I really meant that I lived another day and learned about realloc(p, 0) being implementation dependend. That is all. > -- > Aurelien Jarno GPG: 1024D/F1BCDB73 > aurelien@aurel32.net http://www.aurel32.net
Aurelien Jarno wrote: > On Tue, Dec 29, 2009 at 05:36:40PM +0200, Michael S. Tsirkin wrote: > > 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 <aurelien@aurel32.net> > > > > I didn't know, you live and learn. FWIW > > Can you please stop being annoying about that? What was the annoyance? I don't see what it is and would like to avoid being annoying. Thanks, -- Jamie
On Tue, Dec 29, 2009 at 04:40:33PM +0000, Jamie Lokier wrote: > Aurelien Jarno wrote: > > On Tue, Dec 29, 2009 at 05:36:40PM +0200, Michael S. Tsirkin wrote: > > > 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 <aurelien@aurel32.net> > > > > > > I didn't know, you live and learn. FWIW > > > > Can you please stop being annoying about that? > > What was the annoyance? I don't see what it is and would like to > avoid being annoying. A misunderstanding between Michael and me. Sorry about that.
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)
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 <aurelien@aurel32.net> --- hw/elf_ops.h | 9 +++++++-- 1 files changed, 7 insertions(+), 2 deletions(-)