openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

nfp: bpf: update fixup function for BPF-to-BPF calls support 

Relocation for targets of BPF-to-BPF calls are required at the end of
translation. Update the nfp_fixup_branches() function in that regard.

When checking that the last instruction of each bloc is a branch, we
must account for the length of the instructions required to pop the
return address from the stack.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Quentin Monnet 2018-10-07 12:56:54 +01:00 committed by Daniel Borkmann
parent fb19816541
commit bdf4c66faf
2 changed files with 24 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
drivers/net/ethernet/netronome/nfp/bpf/jit.c
View File

@ -3116,7 +3116,7 @@ static int jne_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
static int
bpf_to_bpf_call(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
u32 ret_tgt, stack_depth;
u32 ret_tgt, stack_depth, offset_br;
swreg tmp_reg;
stack_depth = round_up(nfp_prog->stack_frame_depth, STACK_FRAME_ALIGN);
@ -3160,6 +3160,7 @@ bpf_to_bpf_call(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
ret_tgt = nfp_prog_current_offset(nfp_prog) + 3;
emit_br_relo(nfp_prog, BR_UNC, BR_OFF_RELO, 2,
RELO_BR_GO_CALL_PUSH_REGS);
offset_br = nfp_prog_current_offset(nfp_prog);
wrp_immed_relo(nfp_prog, imm_b(nfp_prog), 0, RELO_IMMED_REL);
wrp_immed_relo(nfp_prog, ret_reg(nfp_prog), ret_tgt, RELO_IMMED_REL);
@ -3176,6 +3177,9 @@ bpf_to_bpf_call(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
wrp_nops(nfp_prog, 3);
}
meta->num_insns_after_br = nfp_prog_current_offset(nfp_prog);
meta->num_insns_after_br -= offset_br;
return 0;
}
@ -3344,21 +3348,36 @@ static int nfp_fixup_branches(struct nfp_prog *nfp_prog)
list_for_each_entry(meta, &nfp_prog->insns, l) {
if (meta->skip)
continue;
if (meta->insn.code == (BPF_JMP | BPF_CALL))
continue;
if (BPF_CLASS(meta->insn.code) != BPF_JMP)
continue;
if (meta->insn.code == (BPF_JMP | BPF_EXIT) &&
!nfp_is_main_function(meta))
continue;
if (is_mbpf_helper_call(meta))
continue;
if (list_is_last(&meta->l, &nfp_prog->insns))
br_idx = nfp_prog->last_bpf_off;
else
br_idx = list_next_entry(meta, l)->off - 1;
/* For BPF-to-BPF function call, a stack adjustment sequence is
* generated after the return instruction. Therefore, we must
* withdraw the length of this sequence to have br_idx pointing
* to where the "branch" NFP instruction is expected to be.
*/
if (is_mbpf_pseudo_call(meta))
br_idx -= meta->num_insns_after_br;
if (!nfp_is_br(nfp_prog->prog[br_idx])) {
pr_err("Fixup found block not ending in branch %d %02x %016llx!!\n",
br_idx, meta->insn.code, nfp_prog->prog[br_idx]);
return -ELOOP;
}
if (meta->insn.code == (BPF_JMP | BPF_EXIT))
continue;
/* Leave special branches for later */
if (FIELD_GET(OP_RELO_TYPE, nfp_prog->prog[br_idx]) !=
RELO_BR_REL)

2
drivers/net/ethernet/netronome/nfp/bpf/main.h
View File

@ -283,6 +283,7 @@ struct nfp_bpf_reg_state {
* @xadd_maybe_16bit: 16bit immediate is possible
* @jmp_dst: destination info for jump instructions
* @jump_neg_op: jump instruction has inverted immediate, use ADD instead of SUB
* @num_insns_after_br: number of insns following a branch jump, used for fixup
* @func_id: function id for call instructions
* @arg1: arg1 for call instructions
* @arg2: arg2 for call instructions
@ -319,6 +320,7 @@ struct nfp_insn_meta {
struct {
struct nfp_insn_meta *jmp_dst;
bool jump_neg_op;
u32 num_insns_after_br; /* only for BPF-to-BPF calls */
};
/* function calls */
struct {