Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754305AbeAMSsr (ORCPT + 1 other); Sat, 13 Jan 2018 13:48:47 -0500 Received: from mail-wm0-f67.google.com ([74.125.82.67]:35363 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752543AbeAMSsp (ORCPT ); Sat, 13 Jan 2018 13:48:45 -0500 X-Google-Smtp-Source: ACJfBouuTkHuEpUjXUXCCFVwqUONbESelue2lT+24GvV/nuVla1HSYrXDOS0jIxvYbvHAfT8zYw5IA== From: Karim Eshapa To: ast@kernel.org Cc: daniel@iogearbox.net, davem@davemloft.net, ecree@solarflare.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Karim Eshapa Subject: [PATCH] Remove structure passing and assignment to save stack and no coping structures. Date: Sat, 13 Jan 2018 20:48:30 +0200 Message-Id: <1515869310-10851-1-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: Signed-off-by: Karim Eshapa Thanks, Karim --- include/linux/tnum.h | 2 +- kernel/bpf/tnum.c | 13 +++++++------ kernel/bpf/verifier.c | 12 ++++++++---- 3 files changed, 16 insertions(+), 11 deletions(-) diff --git a/include/linux/tnum.h b/include/linux/tnum.h index 0d2d3da..ddb1250 100644 --- a/include/linux/tnum.h +++ b/include/linux/tnum.h @@ -26,7 +26,7 @@ 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..f7f8b10 100644 --- a/kernel/bpf/tnum.c +++ b/kernel/bpf/tnum.c @@ -43,16 +43,17 @@ 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 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 +103,7 @@ 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..4acc16c 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -999,7 +999,8 @@ 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_const(ip_align + reg->off + off)); if (!tnum_is_aligned(reg_off, size)) { char tn_buf[48]; @@ -1024,7 +1025,8 @@ static int check_generic_ptr_alignment(struct bpf_verifier_env *env, if (!strict || size == 1) return 0; - reg_off = tnum_add(reg->var_off, tnum_const(reg->off + off)); + tnum_add(®_off, ®->var_off, + &tnum_const(reg->off + off)); if (!tnum_is_aligned(reg_off, size)) { char tn_buf[48]; @@ -1971,7 +1973,8 @@ 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 +2111,8 @@ 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