Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754082AbeAMWD4 (ORCPT + 1 other); Sat, 13 Jan 2018 17:03:56 -0500 Received: from mail-wm0-f68.google.com ([74.125.82.68]:39776 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752168AbeAMWDy (ORCPT ); Sat, 13 Jan 2018 17:03:54 -0500 X-Google-Smtp-Source: ACJfBosdTMDpMGULD5Frtp5gWSXwUrAelGV/RgTX8UFPTpBCBZwiXMuR1VIw2p1fnEtZTYLYc8VyKw== From: Karim Eshapa To: ast@kernel.org Cc: daniel@iogearbox.net, ecree@solarflare.com, davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Karim Eshapa Subject: [PATCH] kernel:bpf Remove structure passing and assignment to save stack and no coping structures Date: Sun, 14 Jan 2018 00:03:42 +0200 Message-Id: <1515881022-15237-1-git-send-email-karim.eshapa@gmail.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: Use pointers to structure as arguments to function instead of coping structures and less stack size. Also transfer TNUM(_v, _m) to tnum.h file to be used in differnet files for creating anonymous structures statically. Signed-off-by: Karim Eshapa Thanks, Karim --- include/linux/tnum.h | 4 +++- kernel/bpf/tnum.c | 14 +++++++------- kernel/bpf/verifier.c | 11 ++++++----- 3 files changed, 16 insertions(+), 13 deletions(-) diff --git a/include/linux/tnum.h b/include/linux/tnum.h index 0d2d3da..72938a0 100644 --- a/include/linux/tnum.h +++ b/include/linux/tnum.h @@ -13,6 +13,8 @@ struct tnum { }; /* Constructors */ +/* Statically tnum constant */ +#define TNUM(_v, _m) (struct tnum){.value = _v, .mask = _m} /* Represent a known constant as a tnum. */ struct tnum tnum_const(u64 value); /* A completely unknown value */ @@ -26,7 +28,7 @@ struct tnum tnum_lshift(struct tnum a, u8 shift); /* Shift a tnum right (by a fixed shift) */ struct tnum tnum_rshift(struct tnum a, u8 shift); /* Add two tnums, return @a + @b */ -struct tnum tnum_add(struct tnum a, struct tnum b); +void tnum_add(struct tnum *res, struct tnum *a, struct tnum *b); /* Subtract two tnums, return @a - @b */ struct tnum tnum_sub(struct tnum a, struct tnum b); /* Bitwise-AND, return @a & @b */ diff --git a/kernel/bpf/tnum.c b/kernel/bpf/tnum.c index 1f4bf68..89e3182 100644 --- a/kernel/bpf/tnum.c +++ b/kernel/bpf/tnum.c @@ -8,7 +8,6 @@ #include #include -#define TNUM(_v, _m) (struct tnum){.value = _v, .mask = _m} /* A completely unknown value */ const struct tnum tnum_unknown = { .value = 0, .mask = -1 }; @@ -43,16 +42,17 @@ struct tnum tnum_rshift(struct tnum a, u8 shift) return TNUM(a.value >> shift, a.mask >> shift); } -struct tnum tnum_add(struct tnum a, struct tnum b) +void tnum_add(struct tnum *res, struct tnum *a, struct tnum *b) { u64 sm, sv, sigma, chi, mu; - sm = a.mask + b.mask; - sv = a.value + b.value; + sm = a->mask + b->mask; + sv = a->value + b->value; sigma = sm + sv; chi = sigma ^ sv; - mu = chi | a.mask | b.mask; - return TNUM(sv & ~mu, mu); + mu = chi | a->mask | b->mask; + res->value = (sv & ~mu); + res->mask = mu; } struct tnum tnum_sub(struct tnum a, struct tnum b) @@ -102,7 +102,7 @@ static struct tnum hma(struct tnum acc, u64 value, u64 mask) { while (mask) { if (mask & 1) - acc = tnum_add(acc, TNUM(0, value)); + tnum_add(&acc, &acc, &TNUM(0, value)); mask >>= 1; value <<= 1; } diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index b414d6b..b31b1c4 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -999,7 +999,7 @@ static int check_pkt_ptr_alignment(struct bpf_verifier_env *env, */ ip_align = 2; - reg_off = tnum_add(reg->var_off, tnum_const(ip_align + reg->off + off)); + tnum_add(®_off, ®->var_off, &TNUM(ip_align + reg->off + off, 0)); if (!tnum_is_aligned(reg_off, size)) { char tn_buf[48]; @@ -1023,8 +1023,7 @@ static int check_generic_ptr_alignment(struct bpf_verifier_env *env, /* Byte size accesses are always allowed. */ if (!strict || size == 1) return 0; - - reg_off = tnum_add(reg->var_off, tnum_const(reg->off + off)); + tnum_add(®_off, ®->var_off, &TNUM(reg->off + off, 0)); if (!tnum_is_aligned(reg_off, size)) { char tn_buf[48]; @@ -1971,7 +1970,8 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, dst_reg->umin_value = umin_ptr + umin_val; dst_reg->umax_value = umax_ptr + umax_val; } - dst_reg->var_off = tnum_add(ptr_reg->var_off, off_reg->var_off); + tnum_add(&dst_reg->var_off, &ptr_reg->var_off, + &off_reg->var_off); dst_reg->off = ptr_reg->off; if (reg_is_pkt_pointer(ptr_reg)) { dst_reg->id = ++env->id_gen; @@ -2108,7 +2108,8 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env, dst_reg->umin_value += umin_val; dst_reg->umax_value += umax_val; } - dst_reg->var_off = tnum_add(dst_reg->var_off, src_reg.var_off); + tnum_add(&dst_reg->var_off, &dst_reg->var_off, + &src_reg.var_off); break; case BPF_SUB: if (signed_sub_overflows(dst_reg->smin_value, smax_val) || -- 2.7.4