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AJvYcCX76jA5G+QsOCT+rBYlNWgumGr+7CKqgK2bLUoq1QbyYJuiPeaYs1ZcN/ratC6AhC7QSuFEwNbtj/y/9b4SKpzeS7eHqmibANSCAql7 X-Gm-Message-State: AOJu0YxuhVDZBHJktMf0Xp7sSw86CDhhcSkFXigJlulnCDzb1LoizkPM SmgGzZnZq7f8Fe0jqyDMYDCwCtmW6kLsxGlF+2kPK6C0ZXHjj+IwWqsHB6hrx9EYE2FKUxoK4Lf wyeT8ZGxSZlcRdyeFYpnkvK9i06KvRmYuFwU0/A== X-Google-Smtp-Source: AGHT+IGq/FPDHURxZuXkT8EEMfyOBxQIWZRGOM045VqtAvTD1CETCELK38VG/mvuBgw8UVUij5Aehjzrk5JxYSrtPyI= X-Received: by 2002:a05:6871:551:b0:218:55c9:bb20 with SMTP id t17-20020a056871055100b0021855c9bb20mr3419259oal.21.1707925596168; Wed, 14 Feb 2024 07:46:36 -0800 (PST) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20240201155532.49707-1-brgl@bgdev.pl> <20240201155532.49707-9-brgl@bgdev.pl> <7tbhdkqpl4iuaxmc73pje2nbbkarxxpgmabc7j4q26d2rhzrv5@ltu6niel5eb4> In-Reply-To: <7tbhdkqpl4iuaxmc73pje2nbbkarxxpgmabc7j4q26d2rhzrv5@ltu6niel5eb4> From: Bartosz Golaszewski Date: Wed, 14 Feb 2024 16:46:25 +0100 Message-ID: Subject: Re: [RFC 8/9] PCI/pwrctl: add PCI power control core code To: Bjorn Andersson Cc: Konrad Dybcio , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Marcel Holtmann , Luiz Augusto von Dentz , Bjorn Helgaas , Neil Armstrong , Alex Elder , Srini Kandagatla , Greg Kroah-Hartman , Arnd Bergmann , Abel Vesa , Manivannan Sadhasivam , Lukas Wunner , linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org, linux-pci@vger.kernel.org, Bartosz Golaszewski Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, Feb 2, 2024 at 4:53=E2=80=AFAM Bjorn Andersson wrote: > [snip] > > > + break; > > + case BUS_NOTIFY_BOUND_DRIVER: > > + pwrctl->link =3D device_link_add(dev, pwrctl->dev, > > + DL_FLAG_AUTOREMOVE_CONSUME= R); > > + if (!pwrctl->link) > > + dev_err(pwrctl->dev, "Failed to add device link\n= "); > > + break; > > + case BUS_NOTIFY_UNBOUND_DRIVER: > > + device_link_del(pwrctl->link); > > This might however become a NULL-pointer dereference, if dev was bound > to its driver before the pci_pwrctl_notify() was registered for the > pwrctl and then the PCI device is unbound. > Right. And it also makes me think that right after registering with the notifier, we should iterate over the PCI bus devices and see if the relevant one is already there. > This would also happen if device_link_add() failed when the PCI device > was bound... > Right. Bart [snip]