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s390/bpf: Only clear A and X for converted BPF programs
Only classic BPF programs that have been converted to eBPF need to clear the A and X registers. We can check for converted programs with: bpf_prog->type == BPF_PROG_TYPE_UNSPEC So add the check and skip initialization for real eBPF programs. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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@ -387,7 +387,7 @@ static void save_restore_regs(struct bpf_jit *jit, int op)
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* Save registers and create stack frame if necessary.
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* See stack frame layout desription in "bpf_jit.h"!
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*/
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static void bpf_jit_prologue(struct bpf_jit *jit)
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static void bpf_jit_prologue(struct bpf_jit *jit, bool is_classic)
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{
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if (jit->seen & SEEN_TAIL_CALL) {
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/* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */
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@ -440,7 +440,8 @@ static void bpf_jit_prologue(struct bpf_jit *jit)
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EMIT6_DISP_LH(0xe3000000, 0x0004, REG_SKB_DATA, REG_0,
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BPF_REG_1, offsetof(struct sk_buff, data));
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}
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/* BPF compatibility: clear A (%b0) and X (%b7) registers */
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/* Clear A (%b0) and X (%b7) registers for converted BPF programs */
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if (is_classic) {
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if (REG_SEEN(BPF_REG_A))
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/* lghi %ba,0 */
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EMIT4_IMM(0xa7090000, BPF_REG_A, 0);
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@ -448,6 +449,7 @@ static void bpf_jit_prologue(struct bpf_jit *jit)
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/* lghi %bx,0 */
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EMIT4_IMM(0xa7090000, BPF_REG_X, 0);
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}
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}
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/*
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* Function epilogue
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@ -1232,7 +1234,7 @@ static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp)
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jit->lit = jit->lit_start;
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jit->prg = 0;
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bpf_jit_prologue(jit);
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bpf_jit_prologue(jit, fp->type == BPF_PROG_TYPE_UNSPEC);
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for (i = 0; i < fp->len; i += insn_count) {
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insn_count = bpf_jit_insn(jit, fp, i);
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if (insn_count < 0)
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