| Message ID | 20210331061218.1647-3-ciara.loftus@intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | None | expand |
On Tue, Mar 30, 2021 at 11:45 PM Ciara Loftus <ciara.loftus@intel.com> wrote: > > If the call to xsk_socket__create fails, the user may want to retry the > socket creation using the same umem. Ensure that the umem is in the > same state on exit if the call fails by: > 1. ensuring the umem _save pointers are unmodified. > 2. not unmapping the set of umem rings that were set up with the umem > during xsk_umem__create, since those maps existed before the call to > xsk_socket__create and should remain in tact even in the event of > failure. > > Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices") > > Signed-off-by: Ciara Loftus <ciara.loftus@intel.com> > --- > tools/lib/bpf/xsk.c | 41 +++++++++++++++++++++++------------------ > 1 file changed, 23 insertions(+), 18 deletions(-) > > diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c > index 443b0cfb45e8..5098d9e3b55a 100644 > --- a/tools/lib/bpf/xsk.c > +++ b/tools/lib/bpf/xsk.c > @@ -743,26 +743,30 @@ static struct xsk_ctx *xsk_get_ctx(struct xsk_umem *umem, int ifindex, > return NULL; > } > > -static void xsk_put_ctx(struct xsk_ctx *ctx) > +static void xsk_put_ctx(struct xsk_ctx *ctx, bool unmap) > { > struct xsk_umem *umem = ctx->umem; > struct xdp_mmap_offsets off; > int err; > > - if (--ctx->refcount == 0) { > - err = xsk_get_mmap_offsets(umem->fd, &off); > - if (!err) { > - munmap(ctx->fill->ring - off.fr.desc, > - off.fr.desc + umem->config.fill_size * > - sizeof(__u64)); > - munmap(ctx->comp->ring - off.cr.desc, > - off.cr.desc + umem->config.comp_size * > - sizeof(__u64)); > - } > + if (--ctx->refcount) > + return; > > - list_del(&ctx->list); > - free(ctx); > - } > + if (!unmap) > + goto out_free; > + > + err = xsk_get_mmap_offsets(umem->fd, &off); > + if (err) > + goto out_free; > + > + munmap(ctx->fill->ring - off.fr.desc, off.fr.desc + umem->config.fill_size * > + sizeof(__u64)); > + munmap(ctx->comp->ring - off.cr.desc, off.cr.desc + umem->config.comp_size * > + sizeof(__u64)); > + > +out_free: > + list_del(&ctx->list); > + free(ctx); > } > > static struct xsk_ctx *xsk_create_ctx(struct xsk_socket *xsk, > @@ -797,8 +801,6 @@ static struct xsk_ctx *xsk_create_ctx(struct xsk_socket *xsk, > memcpy(ctx->ifname, ifname, IFNAMSIZ - 1); > ctx->ifname[IFNAMSIZ - 1] = '\0'; > > - umem->fill_save = NULL; > - umem->comp_save = NULL; > ctx->fill = fill; > ctx->comp = comp; > list_add(&ctx->list, &umem->ctx_list); > @@ -854,6 +856,7 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr, > struct xsk_socket *xsk; > struct xsk_ctx *ctx; > int err, ifindex; > + bool unmap = umem->fill_save != fill; > we are checking !umem only on the next line, so here it can be still NULL. Please send a fix, thanks. > if (!umem || !xsk_ptr || !(rx || tx)) > return -EFAULT; > @@ -994,6 +997,8 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr, > } > > *xsk_ptr = xsk; > + umem->fill_save = NULL; > + umem->comp_save = NULL; > return 0; > > out_mmap_tx: > @@ -1005,7 +1010,7 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr, > munmap(rx_map, off.rx.desc + > xsk->config.rx_size * sizeof(struct xdp_desc)); > out_put_ctx: > - xsk_put_ctx(ctx); > + xsk_put_ctx(ctx, unmap); > out_socket: > if (--umem->refcount) > close(xsk->fd); > @@ -1071,7 +1076,7 @@ void xsk_socket__delete(struct xsk_socket *xsk) > } > } > > - xsk_put_ctx(ctx); > + xsk_put_ctx(ctx, true); > > umem->refcount--; > /* Do not close an fd that also has an associated umem connected > -- > 2.17.1 >
> On Tue, Mar 30, 2021 at 11:45 PM Ciara Loftus <ciara.loftus@intel.com> > wrote: > > > > If the call to xsk_socket__create fails, the user may want to retry the > > socket creation using the same umem. Ensure that the umem is in the > > same state on exit if the call fails by: > > 1. ensuring the umem _save pointers are unmodified. > > 2. not unmapping the set of umem rings that were set up with the umem > > during xsk_umem__create, since those maps existed before the call to > > xsk_socket__create and should remain in tact even in the event of > > failure. > > > > Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and > devices") > > > > Signed-off-by: Ciara Loftus <ciara.loftus@intel.com> > > --- > > tools/lib/bpf/xsk.c | 41 +++++++++++++++++++++++------------------ > > 1 file changed, 23 insertions(+), 18 deletions(-) > > > > diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c > > index 443b0cfb45e8..5098d9e3b55a 100644 > > --- a/tools/lib/bpf/xsk.c > > +++ b/tools/lib/bpf/xsk.c > > @@ -743,26 +743,30 @@ static struct xsk_ctx *xsk_get_ctx(struct > xsk_umem *umem, int ifindex, > > return NULL; > > } > > > > -static void xsk_put_ctx(struct xsk_ctx *ctx) > > +static void xsk_put_ctx(struct xsk_ctx *ctx, bool unmap) > > { > > struct xsk_umem *umem = ctx->umem; > > struct xdp_mmap_offsets off; > > int err; > > > > - if (--ctx->refcount == 0) { > > - err = xsk_get_mmap_offsets(umem->fd, &off); > > - if (!err) { > > - munmap(ctx->fill->ring - off.fr.desc, > > - off.fr.desc + umem->config.fill_size * > > - sizeof(__u64)); > > - munmap(ctx->comp->ring - off.cr.desc, > > - off.cr.desc + umem->config.comp_size * > > - sizeof(__u64)); > > - } > > + if (--ctx->refcount) > > + return; > > > > - list_del(&ctx->list); > > - free(ctx); > > - } > > + if (!unmap) > > + goto out_free; > > + > > + err = xsk_get_mmap_offsets(umem->fd, &off); > > + if (err) > > + goto out_free; > > + > > + munmap(ctx->fill->ring - off.fr.desc, off.fr.desc + umem- > >config.fill_size * > > + sizeof(__u64)); > > + munmap(ctx->comp->ring - off.cr.desc, off.cr.desc + umem- > >config.comp_size * > > + sizeof(__u64)); > > + > > +out_free: > > + list_del(&ctx->list); > > + free(ctx); > > } > > > > static struct xsk_ctx *xsk_create_ctx(struct xsk_socket *xsk, > > @@ -797,8 +801,6 @@ static struct xsk_ctx *xsk_create_ctx(struct > xsk_socket *xsk, > > memcpy(ctx->ifname, ifname, IFNAMSIZ - 1); > > ctx->ifname[IFNAMSIZ - 1] = '\0'; > > > > - umem->fill_save = NULL; > > - umem->comp_save = NULL; > > ctx->fill = fill; > > ctx->comp = comp; > > list_add(&ctx->list, &umem->ctx_list); > > @@ -854,6 +856,7 @@ int xsk_socket__create_shared(struct xsk_socket > **xsk_ptr, > > struct xsk_socket *xsk; > > struct xsk_ctx *ctx; > > int err, ifindex; > > + bool unmap = umem->fill_save != fill; > > > > we are checking !umem only on the next line, so here it can be still > NULL. Please send a fix, thanks. Thank you for catching this. I've sent a fix. Ciara > > > if (!umem || !xsk_ptr || !(rx || tx)) > > return -EFAULT; > > @@ -994,6 +997,8 @@ int xsk_socket__create_shared(struct xsk_socket > **xsk_ptr, > > } > > > > *xsk_ptr = xsk; > > + umem->fill_save = NULL; > > + umem->comp_save = NULL; > > return 0; > > > > out_mmap_tx: > > @@ -1005,7 +1010,7 @@ int xsk_socket__create_shared(struct xsk_socket > **xsk_ptr, > > munmap(rx_map, off.rx.desc + > > xsk->config.rx_size * sizeof(struct xdp_desc)); > > out_put_ctx: > > - xsk_put_ctx(ctx); > > + xsk_put_ctx(ctx, unmap); > > out_socket: > > if (--umem->refcount) > > close(xsk->fd); > > @@ -1071,7 +1076,7 @@ void xsk_socket__delete(struct xsk_socket *xsk) > > } > > } > > > > - xsk_put_ctx(ctx); > > + xsk_put_ctx(ctx, true); > > > > umem->refcount--; > > /* Do not close an fd that also has an associated umem connected > > -- > > 2.17.1 > >
diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index 443b0cfb45e8..5098d9e3b55a 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -743,26 +743,30 @@ static struct xsk_ctx *xsk_get_ctx(struct xsk_umem *umem, int ifindex, return NULL; } -static void xsk_put_ctx(struct xsk_ctx *ctx) +static void xsk_put_ctx(struct xsk_ctx *ctx, bool unmap) { struct xsk_umem *umem = ctx->umem; struct xdp_mmap_offsets off; int err; - if (--ctx->refcount == 0) { - err = xsk_get_mmap_offsets(umem->fd, &off); - if (!err) { - munmap(ctx->fill->ring - off.fr.desc, - off.fr.desc + umem->config.fill_size * - sizeof(__u64)); - munmap(ctx->comp->ring - off.cr.desc, - off.cr.desc + umem->config.comp_size * - sizeof(__u64)); - } + if (--ctx->refcount) + return; - list_del(&ctx->list); - free(ctx); - } + if (!unmap) + goto out_free; + + err = xsk_get_mmap_offsets(umem->fd, &off); + if (err) + goto out_free; + + munmap(ctx->fill->ring - off.fr.desc, off.fr.desc + umem->config.fill_size * + sizeof(__u64)); + munmap(ctx->comp->ring - off.cr.desc, off.cr.desc + umem->config.comp_size * + sizeof(__u64)); + +out_free: + list_del(&ctx->list); + free(ctx); } static struct xsk_ctx *xsk_create_ctx(struct xsk_socket *xsk, @@ -797,8 +801,6 @@ static struct xsk_ctx *xsk_create_ctx(struct xsk_socket *xsk, memcpy(ctx->ifname, ifname, IFNAMSIZ - 1); ctx->ifname[IFNAMSIZ - 1] = '\0'; - umem->fill_save = NULL; - umem->comp_save = NULL; ctx->fill = fill; ctx->comp = comp; list_add(&ctx->list, &umem->ctx_list); @@ -854,6 +856,7 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr, struct xsk_socket *xsk; struct xsk_ctx *ctx; int err, ifindex; + bool unmap = umem->fill_save != fill; if (!umem || !xsk_ptr || !(rx || tx)) return -EFAULT; @@ -994,6 +997,8 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr, } *xsk_ptr = xsk; + umem->fill_save = NULL; + umem->comp_save = NULL; return 0; out_mmap_tx: @@ -1005,7 +1010,7 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr, munmap(rx_map, off.rx.desc + xsk->config.rx_size * sizeof(struct xdp_desc)); out_put_ctx: - xsk_put_ctx(ctx); + xsk_put_ctx(ctx, unmap); out_socket: if (--umem->refcount) close(xsk->fd); @@ -1071,7 +1076,7 @@ void xsk_socket__delete(struct xsk_socket *xsk) } } - xsk_put_ctx(ctx); + xsk_put_ctx(ctx, true); umem->refcount--; /* Do not close an fd that also has an associated umem connected
If the call to xsk_socket__create fails, the user may want to retry the socket creation using the same umem. Ensure that the umem is in the same state on exit if the call fails by: 1. ensuring the umem _save pointers are unmodified. 2. not unmapping the set of umem rings that were set up with the umem during xsk_umem__create, since those maps existed before the call to xsk_socket__create and should remain in tact even in the event of failure. Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices") Signed-off-by: Ciara Loftus <ciara.loftus@intel.com> --- tools/lib/bpf/xsk.c | 41 +++++++++++++++++++++++------------------ 1 file changed, 23 insertions(+), 18 deletions(-)