From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 96F8C1A83A1 for ; Fri, 2 Aug 2024 16:15:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722615344; cv=none; b=LA0WL0R5LVGvFmfv+0JCvCAf5nzr3ZRWPiWC8qSS8B0feGp1L2Axg79vVxfxjT7kkf5ap0GfjccrX5GmUYfDzZ3DWLFx9/AET1sO2tPXhjCI39st5Zj7cjlg2zIuNfcbTI+2C5xtehyBCLApDjhvb2OZXzUaElE30aV6RCnFWI0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722615344; c=relaxed/simple; bh=ilZMM4NaYv40DK38mq7juuAum7aGWknaTsRlWEpVbBU=; h=Message-ID:From:To:Cc:Subject:References:MIME-Version: Content-Type:Date; b=FBdIBOhCMHIwb1I5HBtVqA80eyEY5J2hYZTCBs40p6vcQabt7OrFKaZ7FKG/JDCv2q/50RJQhnhj5Q3nSqurXb4aBRdRODTrSnzYQj9Aqi8AulK7WWT16TeQUIF+h44Lchz0+j0AOGedTx8jERVgvCg2OGG/cuaMHWg9Tkrop3o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=ZqIzkm9Z; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=gr+ayd6O; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="ZqIzkm9Z"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="gr+ayd6O" Message-ID: <20240802155440.275200843@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1722615335; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=VI6ArGD5nH+JTATcGxIw1bvZF42wAjPrLzfbKGCDYP0=; b=ZqIzkm9Zi4c5Sph+AzKrZg02TE9Nk8RvXiqlEHnlHORL2aaQc93kuEBSxCqASHAWoKgdsg z20HpXMxwhtWug4+OsWM08wQC4jPwr2DLxi6nIzkHM52ie8slOhVJ0zJIalvU+d/9pe839 rzQPhhY/AQsweIHQn9+F6Ctmn7kzvUOOboWvX+Ef87qpUWWcSUCO1bQZCCdrotdF/kidpB 5NSij9fuZWYbZfW+96HvA04cuOW8+MmwtJZyMtP3KEIeoR/N+MyTh1v37rRkFHRYZouxPz IxH/rbrLDxOiIAzRss4x45sKhMwzKpnHQ5Li4eOFIVMeIEEoeJEf7DIu1Ls1TQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1722615335; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=VI6ArGD5nH+JTATcGxIw1bvZF42wAjPrLzfbKGCDYP0=; b=gr+ayd6OdYb8XRJqaM6Fl4Rg8CypB0f34dNfn6hWfMwDz8uIjyr0toaobUMl1r6WRpdYVH v8gCX0wh4gWp+PDg== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, Breno Leitao Subject: [patch 01/15] x86/ioapic: Handle allocation failures gracefully References: <20240802155038.556977544@linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Date: Fri, 2 Aug 2024 18:15:34 +0200 (CEST) Breno observed panics when using failslab under certain conditions during runtime: can not alloc irq_pin_list (-1,0,20) Kernel panic - not syncing: IO-APIC: failed to add irq-pin. Can not proceed panic+0x4e9/0x590 mp_irqdomain_alloc+0x9ab/0xa80 irq_domain_alloc_irqs_locked+0x25d/0x8d0 __irq_domain_alloc_irqs+0x80/0x110 mp_map_pin_to_irq+0x645/0x890 acpi_register_gsi_ioapic+0xe6/0x150 hpet_open+0x313/0x480 That's a pointless panic which is a leftover of the historic IO/APIC code which panic'ed during early boot when the interrupt allocation failed. The only place which might justify panic is the PIT/HPET timer_check() code which tries to figure out whether the timer interrupt is delivered through the IO/APIC. But that code does not require to handle interrupt allocation failures. If the interrupt cannot be allocated then timer delivery fails and it either panics due to that or falls back to legacy mode. Cure this by removing the panic wrapper around __add_pin_to_irq_node() and making mp_irqdomain_alloc() aware of the failure condition and handle it as any other failure in this function gracefully. Reported-by: Breno Leitao Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/ZqfJmUF8sXIyuSHN@gmail.com --- arch/x86/kernel/apic/io_apic.c | 46 +++++++++++++++++++---------------------- 1 file changed, 22 insertions(+), 24 deletions(-) --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -352,27 +352,26 @@ static void ioapic_mask_entry(int apic, * shared ISA-space IRQs, so we have to support them. We are super * fast in the common case, and fast for shared ISA-space IRQs. */ -static int __add_pin_to_irq_node(struct mp_chip_data *data, - int node, int apic, int pin) +static bool add_pin_to_irq_node(struct mp_chip_data *data, int node, int apic, int pin) { struct irq_pin_list *entry; - /* don't allow duplicates */ - for_each_irq_pin(entry, data->irq_2_pin) + /* Don't allow duplicates */ + for_each_irq_pin(entry, data->irq_2_pin) { if (entry->apic == apic && entry->pin == pin) - return 0; + return true; + } entry = kzalloc_node(sizeof(struct irq_pin_list), GFP_ATOMIC, node); if (!entry) { - pr_err("can not alloc irq_pin_list (%d,%d,%d)\n", - node, apic, pin); - return -ENOMEM; + pr_err("Cannot allocate irq_pin_list (%d,%d,%d)\n", node, apic, pin); + return false; } + entry->apic = apic; entry->pin = pin; list_add_tail(&entry->list, &data->irq_2_pin); - - return 0; + return true; } static void __remove_pin_from_irq(struct mp_chip_data *data, int apic, int pin) @@ -387,13 +386,6 @@ static void __remove_pin_from_irq(struct } } -static void add_pin_to_irq_node(struct mp_chip_data *data, - int node, int apic, int pin) -{ - if (__add_pin_to_irq_node(data, node, apic, pin)) - panic("IO-APIC: failed to add irq-pin. Can not proceed\n"); -} - /* * Reroute an IRQ to a different pin. */ @@ -1002,8 +994,7 @@ static int alloc_isa_irq_from_domain(str if (irq_data && irq_data->parent_data) { if (!mp_check_pin_attr(irq, info)) return -EBUSY; - if (__add_pin_to_irq_node(irq_data->chip_data, node, ioapic, - info->ioapic.pin)) + if (!add_pin_to_irq_node(irq_data->chip_data, node, ioapic, info->ioapic.pin)) return -ENOMEM; } else { info->flags |= X86_IRQ_ALLOC_LEGACY; @@ -3017,10 +3008,8 @@ int mp_irqdomain_alloc(struct irq_domain return -ENOMEM; ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, info); - if (ret < 0) { - kfree(data); - return ret; - } + if (ret < 0) + goto free_data; INIT_LIST_HEAD(&data->irq_2_pin); irq_data->hwirq = info->ioapic.pin; @@ -3029,7 +3018,10 @@ int mp_irqdomain_alloc(struct irq_domain irq_data->chip_data = data; mp_irqdomain_get_attr(mp_pin_to_gsi(ioapic, pin), data, info); - add_pin_to_irq_node(data, ioapic_alloc_attr_node(info), ioapic, pin); + if (!add_pin_to_irq_node(data, ioapic_alloc_attr_node(info), ioapic, pin)) { + ret = -ENOMEM; + goto free_irqs; + } mp_preconfigure_entry(data); mp_register_handler(virq, data->is_level); @@ -3044,6 +3036,12 @@ int mp_irqdomain_alloc(struct irq_domain ioapic, mpc_ioapic_id(ioapic), pin, virq, data->is_level, data->active_low); return 0; + +free_irqs: + irq_domain_free_irqs_parent(domain, virq, nr_irqs); +free_data: + kfree(data); + return ret; } void mp_irqdomain_free(struct irq_domain *domain, unsigned int virq,