| Message ID | 20201127175738.1085417-4-jackmanb@google.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF |
| Headers | show |
| Series | Atomics for eBPF | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for bpf-next |
| netdev/subject_prefix | success | Link |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 0 this patch: 0 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | warning | CHECK: Please don't use multiple blank lines |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 3 this patch: 3 |
| netdev/header_inline | success | Link |
| netdev/stable | success | Stable not CCed |
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index a839c1a54276..49dea0c1a130 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -783,6 +783,22 @@ static void emit_stx(u8 **pprog, u32 size, u32 dst_reg, u32 src_reg, int off) *pprog = prog; } + +static void emit_neg(u8 **pprog, u32 reg, bool is64) +{ + u8 *prog = *pprog; + int cnt = 0; + + /* Emit REX byte if necessary */ + if (is64) + EMIT1(add_1mod(0x48, reg)); + else if (is_ereg(reg)) + EMIT1(add_1mod(0x40, reg)); + + EMIT2(0xF7, add_1reg(0xD8, reg)); /* x86 NEG */ + *pprog = prog; +} + static bool ex_handler_bpf(const struct exception_table_entry *x, struct pt_regs *regs, int trapnr, unsigned long error_code, unsigned long fault_addr) @@ -884,11 +900,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, /* neg dst */ case BPF_ALU | BPF_NEG: case BPF_ALU64 | BPF_NEG: - if (BPF_CLASS(insn->code) == BPF_ALU64) - EMIT1(add_1mod(0x48, dst_reg)); - else if (is_ereg(dst_reg)) - EMIT1(add_1mod(0x40, dst_reg)); - EMIT2(0xF7, add_1reg(0xD8, dst_reg)); + emit_neg(&prog, dst_reg, + BPF_CLASS(insn->code) == BPF_ALU64); break; case BPF_ALU | BPF_ADD | BPF_K:
There's currently only one usage of this but implementation of atomic_sub add another. Signed-off-by: Brendan Jackman <jackmanb@google.com> --- arch/x86/net/bpf_jit_comp.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-)