diff options
| author | Ingo Molnar <mingo@kernel.org> | 2020-05-25 15:10:37 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-05-25 15:10:37 +0200 |
| commit | a5d8e55b2c7d3d18d7837af0ef8d1477eeeb919c (patch) | |
| tree | fe07d3af2f6f13d005da832fe3d18d5d257fb9bd /arch/x86/net/bpf_jit_comp.c | |
| parent | 4da0b2b7e67524cc206067865666899bc02e1cb0 (diff) | |
| parent | 9cb1fd0efd195590b828b9b865421ad345a4a145 (diff) | |
Merge tag 'v5.7-rc7' into efi/core, to refresh the branch and pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/net/bpf_jit_comp.c')
| -rw-r--r-- | arch/x86/net/bpf_jit_comp.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 5ea7c2cf7ab4..42b6709e6dc7 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -158,6 +158,19 @@ static bool is_ereg(u32 reg) BIT(BPF_REG_AX)); } +/* + * is_ereg_8l() == true if BPF register 'reg' is mapped to access x86-64 + * lower 8-bit registers dil,sil,bpl,spl,r8b..r15b, which need extra byte + * of encoding. al,cl,dl,bl have simpler encoding. + */ +static bool is_ereg_8l(u32 reg) +{ + return is_ereg(reg) || + (1 << reg) & (BIT(BPF_REG_1) | + BIT(BPF_REG_2) | + BIT(BPF_REG_FP)); +} + static bool is_axreg(u32 reg) { return reg == BPF_REG_0; @@ -598,9 +611,8 @@ static void emit_stx(u8 **pprog, u32 size, u32 dst_reg, u32 src_reg, int off) switch (size) { case BPF_B: /* Emit 'mov byte ptr [rax + off], al' */ - if (is_ereg(dst_reg) || is_ereg(src_reg) || - /* We have to add extra byte for x86 SIL, DIL regs */ - src_reg == BPF_REG_1 || src_reg == BPF_REG_2) + if (is_ereg(dst_reg) || is_ereg_8l(src_reg)) + /* Add extra byte for eregs or SIL,DIL,BPL in src_reg */ EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); else EMIT1(0x88); |