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linux-next@vger.kernel.org, llvm@lists.linux.dev, Johannes Berg , spasswolf@web.de, Thomas Gleixner Date: Wed, 14 May 2025 11:32:58 +0200 In-Reply-To: <7471a185adcc34a79c2ab8ce1e87ab922ae2232b.camel@web.de> References: <20250513164807.51780-1-spasswolf@web.de> <87h61ojg3g.ffs@tglx> <7471a185adcc34a79c2ab8ce1e87ab922ae2232b.camel@web.de> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.56.1-1 Precedence: bulk X-Mailing-List: linux-next@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:Z9f+FBmpI6CKPZ4U3J4iY7BOuQWizzUEw39fK2w6yLquPr4XJlH 3sjGwlUhRWwd0ppHynUUIf+p6YFaJTojRUbmRvqUP7WeHYdfWw6Gm45NZEHUOHB/QkVY5L/ duy3k9mvGe8YUXSH8McsJgD2jXpl4q5mdYPXgUZCaEXMbJyQwBNNPF3RwwmEhWNCuac5X62 BIRA3oInY35aplzMLq/kA== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:r87TRTUMPKE=;VLAAbX6nMiBvVz78pNITpFcja2w BjY0zBVl1ln0sPb/2qqw2DFDKP8G606EZNZeVlRBziADubDnkF5JOp3hn7Ic5nWH6mxyVrpxN 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x5Q4lqtc+Vg7Z8RPeDhbwTXYhmYKW6O1u94TEC5GdSKPmxyUT7MnswNFeLlcyAkm9Pw0mzw4b G1IanTLds8R9jQs0C+MyHQkQtiQY7Rw+jAgBN3xxR6hx4aouVIZkBCbvwVT+6nH6aG1QBLu4R MYgkIbBKtovqo39haD5pihyqMixEO+ukozX84Unu3JgCsMjs9n4U26q+t01L4dcLTBVw6ghu7 rts8Tm0OvZyI8zxxoMw/DnE1jO4qwnj8+XsGBrEceU4R0/FmK/PsYmBg== Am Mittwoch, dem 14.05.2025 um 02:11 +0200 schrieb Bert Karwatzki: > Am Mittwoch, dem 14.05.2025 um 00:33 +0200 schrieb Thomas Gleixner: > > On Tue, May 13 2025 at 18:48, Bert Karwatzki wrote: > > > >=20 > > > > I'll now start a bisection where I revert 76a853f86c97 where possi= ble in > > > > order to find the remaining bugs. > > >=20 > > > The second bisection (from v6.15-rc6 to next-20250512) is finished n= ow: > > >=20 > > > This commit leads to lockups and kernel panics after > > > watching ~5-10min of a youtube video while compiling a kernel, > > > reverting it in next-20250512 is possible: > > > 76a853f86c97 ("wifi: free SKBTX_WIFI_STATUS skb tx_flags flag") > > > This commit leads to the boot failure, reverting leads to the > > > compile error it is supposed to fix: > > > 97f4b999e0c8 ("genirq: Use scoped_guard() to shut clang up") > >=20 > > I really have a hard time to understand what you are trying to explain > > here. 'This commit leads..' is so unspecified that I can't make any > > sense of it. > >=20 > > Also please make sure that you have commit b5fcb6898202 ("genirq: Ensu= re > > flags in lock guard is consistently initialized") in your tree when > > re-testing. That's fixing another subtle (AFAICT clang only) problem i= n > > the guard conversion. If it's not in next yet, you can just merge > >=20 > > git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git irq/core > >=20 > > into next or wait for the next next integration. > >=20 > > Thanks > >=20 > > tglx >=20 >=20 > I merged git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git irq/c= ore into > next-20250513 and this fixes the boot failure but the system still locks= up > after a few minutes (with flashing capslock). To solve this I need to re= vert=20 > 76a853f86c97 ("wifi: free SKBTX_WIFI_STATUS skb tx_flags flag") >=20 > Also commit 97f4b999e0c8 did not actually cause the boot failure that wa= s a > bisection error. >=20 > Bert Karwatzki To investigate the problem with commit 76a853f86c97 ("wifi: free SKBTX_WIFI_STATUS skb tx_flags flag") I used next-20250513 with irq/core m= erged to fix the boot issue and the reverted commit 76a853f86c97.=20 $ git log --oneline bb3ff0e21a16 Revert "wifi: free SKBTX_WIFI_STATUS skb tx_flags flag" 28d1f7734aa3 Merge branch 'irq/core' into clang_panic aa94665adc28 (tag: next-20250513, origin/master, origin/HEAD, master) Add = linux- next specific files for 20250513 Then I reapplied commit 76a853f86c97 hunk by hunk and found the one hunk t= hat causes the problem: diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 3e751dd3ae7b..63df21228029 100644 =2D-- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -4648,8 +4648,7 @@ static void ieee80211_8023_xmit(struct ieee80211_sub_if_data *sdata, memcpy(IEEE80211_SKB_CB(seg), info, sizeof(*info))= ; } =20 - if (unlikely(skb->sk && - skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS)) { + if (unlikely(skb->sk && sock_flag(skb->sk, SOCK_WIFI_STATUS))) { info->status_data =3D ieee80211_store_ack_skb(local, skb, &info->flags, = NULL); if (info->status_data) This is enough to cause a kernel panic when compiled with clang (clang-19.= 1.7 from debian sid). Compiling the same kernel with gcc (gcc-14.2.0 from debi= an sid) shows no problem. The wifi card used is 04:00.0 Network controller [0280]: MEDIATEK Corp. MT7921K (RZ608) Wi-Fi 6E= 80MHz [14c3:0608] Bert Karwatzki