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Wed, 13 Mar 2024 07:14:24 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id dM3kAlBS8WWySAAAD6G6ig (envelope-from ); Wed, 13 Mar 2024 07:14:24 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 5235f45e-e109-11ee-afdd-a90da7624cb6 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1710314064; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=WaNFizuX+HpD4/5IgMI1rgARw+12/nL76PmtgllkKJ0=; b=UoywMclp7TJYR91IhMV5U07zPMiTVrKqIXuCdOeYZZI4+snSxSOAmhNgkwR1+9eNhqvEHJ oJkI5PAD0SyxktGTNUtz1B+bwPyMQ89NaDpemlhVcEzwvYw8POk8o8qaa3cDOEYxo1LT1f Pr/hjgxHYfcfMh7WaiitQ3QSY3awRy0= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1710314064; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=WaNFizuX+HpD4/5IgMI1rgARw+12/nL76PmtgllkKJ0=; b=UoywMclp7TJYR91IhMV5U07zPMiTVrKqIXuCdOeYZZI4+snSxSOAmhNgkwR1+9eNhqvEHJ oJkI5PAD0SyxktGTNUtz1B+bwPyMQ89NaDpemlhVcEzwvYw8POk8o8qaa3cDOEYxo1LT1f Pr/hjgxHYfcfMh7WaiitQ3QSY3awRy0= From: Juergen Gross To: linux-kernel@vger.kernel.org Cc: Juergen Gross , Stefano Stabellini , Oleksandr Tyshchenko , xen-devel@lists.xenproject.org Subject: [PATCH 2/2] xen/events: increment refcnt only if event channel is refcounted Date: Wed, 13 Mar 2024 08:14:09 +0100 Message-Id: <20240313071409.25913-3-jgross@suse.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240313071409.25913-1-jgross@suse.com> References: <20240313071409.25913-1-jgross@suse.com> MIME-Version: 1.0 X-Spamd-Bar: +++ Authentication-Results: smtp-out2.suse.de; dkim=pass header.d=suse.com header.s=susede1 header.b=UoywMclp X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Spamd-Result: default: False [3.49 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; R_DKIM_ALLOW(-0.20)[suse.com:s=susede1]; SPAMHAUS_XBL(0.00)[2a07:de40:b281:104:10:150:64:97:from]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; R_MISSING_CHARSET(2.50)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; BROKEN_CONTENT_TYPE(1.50)[]; RCPT_COUNT_FIVE(0.00)[5]; NEURAL_HAM_LONG(-1.00)[-1.000]; RCVD_COUNT_THREE(0.00)[3]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; DKIM_TRACE(0.00)[suse.com:+]; MX_GOOD(-0.01)[]; MID_CONTAINS_FROM(1.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:dkim,suse.com:email]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; NEURAL_HAM_SHORT(-0.20)[-0.995]; RCVD_TLS_ALL(0.00)[] X-Rspamd-Queue-Id: 4C52E1F7A4 In bind_evtchn_to_irq_chip() don't increment the refcnt of the event channel blindly. In case the event channel is NOT refcounted, issue a warning instead. Add an additional safety net by doing the refcnt increment only if the caller has specified IRQF_SHARED in the irqflags parameter. Fixes: 9e90e58c11b7 ("xen: evtchn: Allow shared registration of IRQ handers") Signed-off-by: Juergen Gross Reviewed-by: Oleksandr Tyshchenko --- drivers/xen/events/events_base.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 2faa4bf78c7a..81effbd53dc5 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -1190,7 +1190,7 @@ int xen_pirq_from_irq(unsigned irq) EXPORT_SYMBOL_GPL(xen_pirq_from_irq); static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip, - struct xenbus_device *dev) + struct xenbus_device *dev, bool shared) { int ret = -ENOMEM; struct irq_info *info; @@ -1224,7 +1224,8 @@ static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip, */ bind_evtchn_to_cpu(info, 0, false); } else if (!WARN_ON(info->type != IRQT_EVTCHN)) { - info->refcnt++; + if (shared && !WARN_ON(info->refcnt < 0)) + info->refcnt++; } ret = info->irq; @@ -1237,13 +1238,13 @@ static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip, int bind_evtchn_to_irq(evtchn_port_t evtchn) { - return bind_evtchn_to_irq_chip(evtchn, &xen_dynamic_chip, NULL); + return bind_evtchn_to_irq_chip(evtchn, &xen_dynamic_chip, NULL, false); } EXPORT_SYMBOL_GPL(bind_evtchn_to_irq); int bind_evtchn_to_irq_lateeoi(evtchn_port_t evtchn) { - return bind_evtchn_to_irq_chip(evtchn, &xen_lateeoi_chip, NULL); + return bind_evtchn_to_irq_chip(evtchn, &xen_lateeoi_chip, NULL, false); } EXPORT_SYMBOL_GPL(bind_evtchn_to_irq_lateeoi); @@ -1295,7 +1296,8 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu) static int bind_interdomain_evtchn_to_irq_chip(struct xenbus_device *dev, evtchn_port_t remote_port, - struct irq_chip *chip) + struct irq_chip *chip, + bool shared) { struct evtchn_bind_interdomain bind_interdomain; int err; @@ -1307,14 +1309,14 @@ static int bind_interdomain_evtchn_to_irq_chip(struct xenbus_device *dev, &bind_interdomain); return err ? : bind_evtchn_to_irq_chip(bind_interdomain.local_port, - chip, dev); + chip, dev, shared); } int bind_interdomain_evtchn_to_irq_lateeoi(struct xenbus_device *dev, evtchn_port_t remote_port) { return bind_interdomain_evtchn_to_irq_chip(dev, remote_port, - &xen_lateeoi_chip); + &xen_lateeoi_chip, false); } EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq_lateeoi); @@ -1430,7 +1432,8 @@ static int bind_evtchn_to_irqhandler_chip(evtchn_port_t evtchn, { int irq, retval; - irq = bind_evtchn_to_irq_chip(evtchn, chip, NULL); + irq = bind_evtchn_to_irq_chip(evtchn, chip, NULL, + irqflags & IRQF_SHARED); if (irq < 0) return irq; retval = request_irq(irq, handler, irqflags, devname, dev_id); @@ -1471,7 +1474,8 @@ static int bind_interdomain_evtchn_to_irqhandler_chip( { int irq, retval; - irq = bind_interdomain_evtchn_to_irq_chip(dev, remote_port, chip); + irq = bind_interdomain_evtchn_to_irq_chip(dev, remote_port, chip, + irqflags & IRQF_SHARED); if (irq < 0) return irq;