On Mon, 2023-09-25 at 14:53 -0700, Song Liu wrote:
> This set enables allocating bpf trampoline from bpf_prog_pack on x86.
> The
> majority of this work, however, is the refactoring of trampoline
> code.
> This is needed because we need to handle 4 archs and 2 users
> (trampoline
> and struct_ops).
>
> 1/8 is a dependency that is already applied to bpf tree.
> 2/8 through 7/8 refactors trampoline code. A few helpers are added.
> 8/8 finally let bpf trampoline on x86 use bpf_prog_pack.
>
> Changes in v2:
> 1. Add missing changes in net/bpf/bpf_dummy_struct_ops.c.
> 2. Reduce one dry run in arch_prepare_bpf_trampoline. (Xu Kuohai)
> 3. Other small fixes.
>
> Song Liu (8):
> s390/bpf: Let arch_prepare_bpf_trampoline return program size
> bpf: Let bpf_prog_pack_free handle any pointer
> bpf: Adjust argument names of arch_prepare_bpf_trampoline()
> bpf: Add helpers for trampoline image management
> bpf, x86: Adjust arch_prepare_bpf_trampoline return value
> bpf: Add arch_bpf_trampoline_size()
> bpf: Use arch_bpf_trampoline_size
> x86, bpf: Use bpf_prog_pack for bpf trampoline
>
> arch/arm64/net/bpf_jit_comp.c | 55 +++++++++-----
> arch/riscv/net/bpf_jit_comp64.c | 24 ++++---
> arch/s390/net/bpf_jit_comp.c | 43 ++++++-----
> arch/x86/net/bpf_jit_comp.c | 124 +++++++++++++++++++++++++-----
> --
> include/linux/bpf.h | 12 +++-
> include/linux/filter.h | 2 +-
> kernel/bpf/bpf_struct_ops.c | 19 +++--
> kernel/bpf/core.c | 21 +++---
> kernel/bpf/dispatcher.c | 5 +-
> kernel/bpf/trampoline.c | 93 ++++++++++++++++++------
> net/bpf/bpf_dummy_struct_ops.c | 7 +-
> 11 files changed, 277 insertions(+), 128 deletions(-)
>
> --
> 2.34.1
Regarding the s390x part, arch_prepare_bpf_trampoline() needs to call
__arch_prepare_bpf_trampoline() twice: the first time in order to
compute various offsets, the second time to actually emit the code. So
I would suggest to either keep the loop or use the following fixup:
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -2645,7 +2645,15 @@ int arch_prepare_bpf_trampoline(struct
bpf_tramp_image *im, void *image,
struct bpf_tramp_jit tjit;
int ret;
+ /* Compute offsets. */
memset(&tjit, 0, sizeof(tjit));
+ ret = __arch_prepare_bpf_trampoline(im, &tjit, m, flags,
+ tlinks, func_addr);
+ if (ret < 0)
+ return ret;
+
+ /* Generate the code. */
+ tjit.common.prg = 0;
tjit.common.prg_buf = image;
ret = __arch_prepare_bpf_trampoline(im, &tjit, m, flags,
tlinks, func_addr);
With that:
Acked-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
Tested-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx> # on s390x
for the series.
