public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed
From: Sasha Levin <sashal@kernel•org>
To: linux-kernel@vger•kernel.org, stable@vger•kernel.org
Cc: Andrii Nakryiko <andriin@fb•com>, Alexei Starovoitov <ast@fb•com>,
	Daniel Borkmann <daniel@iogearbox•net>,
	Sasha Levin <sashal@kernel•org>,
	linux-kselftest@vger•kernel.org, netdev@vger•kernel.org,
	bpf@vger•kernel.org, clang-built-linux@googlegroups•com
Subject: [PATCH AUTOSEL 5.3 50/71] selftests/bpf: adjust strobemeta loop to satisfy latest clang
Date: Tue,  1 Oct 2019 12:39:00 -0400	[thread overview]
Message-ID: <20191001163922.14735-50-sashal@kernel.org> (raw)
In-Reply-To: <20191001163922.14735-1-sashal@kernel.org>

From: Andrii Nakryiko <andriin@fb•com>

[ Upstream commit 4670d68b9254710fdeaf794cad54d8b2c9929e0a ]

Some recent changes in latest Clang started causing the following
warning when unrolling strobemeta test case main loop:

  progs/strobemeta.h:416:2: warning: loop not unrolled: the optimizer was
  unable to perform the requested transformation; the transformation might
  be disabled or specified as part of an unsupported transformation
  ordering [-Wpass-failed=transform-warning]

This patch simplifies loop's exit condition to depend only on constant
max iteration number (STROBE_MAX_MAP_ENTRIES), while moving early
termination logic inside the loop body. The changes are equivalent from
program logic standpoint, but fixes the warning. It also appears to
improve generated BPF code, as it fixes previously failing non-unrolled
strobemeta test cases.

Cc: Alexei Starovoitov <ast@fb•com>
Signed-off-by: Andrii Nakryiko <andriin@fb•com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox•net>
Signed-off-by: Sasha Levin <sashal@kernel•org>
---
 tools/testing/selftests/bpf/progs/strobemeta.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/progs/strobemeta.h b/tools/testing/selftests/bpf/progs/strobemeta.h
index 8a399bdfd9203..067eb625d01c5 100644
--- a/tools/testing/selftests/bpf/progs/strobemeta.h
+++ b/tools/testing/selftests/bpf/progs/strobemeta.h
@@ -413,7 +413,10 @@ static __always_inline void *read_map_var(struct strobemeta_cfg *cfg,
 #else
 #pragma unroll
 #endif
-	for (int i = 0; i < STROBE_MAX_MAP_ENTRIES && i < map.cnt; ++i) {
+	for (int i = 0; i < STROBE_MAX_MAP_ENTRIES; ++i) {
+		if (i >= map.cnt)
+			break;
+
 		descr->key_lens[i] = 0;
 		len = bpf_probe_read_str(payload, STROBE_MAX_STR_LEN,
 					 map.entries[i].key);
-- 
2.20.1


  parent reply	other threads:[~2019-10-01 17:00 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20191001163922.14735-1-sashal@kernel.org>
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 05/71] xprtrdma: Toggle XPRT_CONGESTED in xprtrdma's slot methods Sasha Levin
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 06/71] xprtrdma: Send Queue size grows after a reconnect Sasha Levin
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 07/71] 9p: Transport error uninitialized Sasha Levin
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 16/71] SUNRPC: RPC level errors should always set task->tk_rpc_status Sasha Levin
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 18/71] netfilter: nf_tables: allow lookups in dynamic sets Sasha Levin
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 23/71] SUNRPC: Don't try to parse incomplete RPC messages Sasha Levin
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 24/71] net/sched: act_sample: don't push mac header on ip6gre ingress Sasha Levin
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 26/71] cdc_ncm: fix divide-by-zero caused by invalid wMaxPacketSize Sasha Levin
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 27/71] usbnet: ignore endpoints with " Sasha Levin
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 28/71] net/phy: fix DP83865 10 Mbps HDX loopback disable function Sasha Levin
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 29/71] net_sched: add max len check for TCA_KIND Sasha Levin
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 30/71] selftests/seccomp: fix build on older kernels Sasha Levin
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 37/71] net/mlx5e: Fix matching on tunnel addresses type Sasha Levin
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 38/71] net/mlx5e: Fix traffic duplication in ethtool steering Sasha Levin
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 42/71] arcnet: provide a buffer big enough to actually receive packets Sasha Levin
2019-10-01 16:38 ` [PATCH AUTOSEL 5.3 44/71] ppp: Fix memory leak in ppp_write Sasha Levin
2019-10-01 16:39 ` Sasha Levin [this message]
2019-10-01 16:39 ` [PATCH AUTOSEL 5.3 52/71] libbpf: fix false uninitialized variable warning Sasha Levin
2019-10-01 16:39 ` [PATCH AUTOSEL 5.3 55/71] bpf: Fix bpf_event_output re-entry issue Sasha Levin
2019-10-01 16:39 ` [PATCH AUTOSEL 5.3 56/71] macsec: drop skb sk before calling gro_cells_receive Sasha Levin
2019-10-01 16:39 ` [PATCH AUTOSEL 5.3 57/71] net: dsa: microchip: Always set regmap stride to 1 Sasha Levin
2019-10-01 16:39 ` [PATCH AUTOSEL 5.3 60/71] nfp: flower: fix memory leak in nfp_flower_spawn_vnic_reprs Sasha Levin
2019-10-01 16:39 ` [PATCH AUTOSEL 5.3 61/71] net: stmmac: Fix page pool size Sasha Levin
2019-10-01 16:39 ` [PATCH AUTOSEL 5.3 62/71] net: phy: micrel: add Asym Pause workaround for KSZ9021 Sasha Levin
2019-10-01 16:39 ` [PATCH AUTOSEL 5.3 63/71] mlxsw: spectrum_flower: Fail in case user specifies multiple mirror actions Sasha Levin
2019-10-01 16:39 ` [PATCH AUTOSEL 5.3 64/71] vrf: Do not attempt to create IPv6 mcast rule if IPv6 is disabled Sasha Levin
2019-10-01 16:39 ` [PATCH AUTOSEL 5.3 65/71] nfp: flower: prevent memory leak in nfp_flower_spawn_phy_reprs Sasha Levin
2019-10-01 16:39 ` [PATCH AUTOSEL 5.3 66/71] nfp: abm: fix memory leak in nfp_abm_u32_knode_replace Sasha Levin
2019-10-01 16:39 ` [PATCH AUTOSEL 5.3 69/71] usbnet: sanity checking of packet sizes and device mtu Sasha Levin
2019-10-01 16:39 ` [PATCH AUTOSEL 5.3 70/71] sch_netem: fix a divide by zero in tabledist() Sasha Levin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191001163922.14735-50-sashal@kernel.org \
    --to=sashal@kernel$(echo .)org \
    --cc=andriin@fb$(echo .)com \
    --cc=ast@fb$(echo .)com \
    --cc=bpf@vger$(echo .)kernel.org \
    --cc=clang-built-linux@googlegroups$(echo .)com \
    --cc=daniel@iogearbox$(echo .)net \
    --cc=linux-kernel@vger$(echo .)kernel.org \
    --cc=linux-kselftest@vger$(echo .)kernel.org \
    --cc=netdev@vger$(echo .)kernel.org \
    --cc=stable@vger$(echo .)kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox