| Message ID | 0ea8655bc24a1ea3da6da66adcb2410aebc55db6.1430908146.git.daniel@iogearbox.net |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On 5/6/15 7:12 AM, Daniel Borkmann wrote: > When seccomp BPF was added, it was discussed to add __GFP_NOWARN > flag for their configuration path as f.e. up to 32K allocations are > more prone to fail under stress. As we're going to reuse BPF API, > add __GFP_NOWARN flags where larger kmalloc() and friends allocations > could fail. > > It doesn't make much sense to pass around __GFP_NOWARN everywhere as > an extra argument only for seccomp while we just as well could run > into similar issues for socket filters, where it's not desired to > have a user application throw a WARN() due to allocation failure. > > Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> > Cc: Nicolas Schichan <nschichan@freebox.fr> > Cc: Alexei Starovoitov <ast@plumgrid.com> > Cc: Kees Cook <keescook@chromium.org> Acked-by: Alexei Starovoitov <ast@plumgrid.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/core/filter.c b/net/core/filter.c index f887084..45c015d 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -371,7 +371,8 @@ static int bpf_convert_filter(struct sock_filter *prog, int len, return -EINVAL; if (new_prog) { - addrs = kcalloc(len, sizeof(*addrs), GFP_KERNEL); + addrs = kcalloc(len, sizeof(*addrs), + GFP_KERNEL | __GFP_NOWARN); if (!addrs) return -ENOMEM; } @@ -839,7 +840,9 @@ static int bpf_prog_store_orig_filter(struct bpf_prog *fp, fkprog = fp->orig_prog; fkprog->len = fprog->len; - fkprog->filter = kmemdup(fp->insns, fsize, GFP_KERNEL); + + fkprog->filter = kmemdup(fp->insns, fsize, + GFP_KERNEL | __GFP_NOWARN); if (!fkprog->filter) { kfree(fp->orig_prog); return -ENOMEM; @@ -941,7 +944,7 @@ static struct bpf_prog *bpf_migrate_filter(struct bpf_prog *fp) * pass. At this time, the user BPF is stored in fp->insns. */ old_prog = kmemdup(fp->insns, old_len * sizeof(struct sock_filter), - GFP_KERNEL); + GFP_KERNEL | __GFP_NOWARN); if (!old_prog) { err = -ENOMEM; goto out_err;
When seccomp BPF was added, it was discussed to add __GFP_NOWARN flag for their configuration path as f.e. up to 32K allocations are more prone to fail under stress. As we're going to reuse BPF API, add __GFP_NOWARN flags where larger kmalloc() and friends allocations could fail. It doesn't make much sense to pass around __GFP_NOWARN everywhere as an extra argument only for seccomp while we just as well could run into similar issues for socket filters, where it's not desired to have a user application throw a WARN() due to allocation failure. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Nicolas Schichan <nschichan@freebox.fr> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Kees Cook <keescook@chromium.org> --- net/core/filter.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)