OpenCloudOS-Kernel/kernel/irq/resend.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 22:07:57 +08:00
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
* Copyright (C) 2005-2006, Thomas Gleixner
*
* This file contains the IRQ-resend code
*
* If the interrupt is waiting to be processed, we try to re-run it.
* We can't directly run it from here since the caller might be in an
* interrupt-protected region. Not all irq controller chips can
* retrigger interrupts at the hardware level, so in those cases
* we allow the resending of IRQs via a tasklet.
*/
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/interrupt.h>
#include "internals.h"
#ifdef CONFIG_HARDIRQS_SW_RESEND
/* Bitmap to handle software resend of interrupts: */
genirq: Prevent access beyond allocated_irqs bitmap Lars-Peter Clausen pointed out: I stumbled upon this while looking through the existing archs using SPARSE_IRQ. Even with SPARSE_IRQ the NR_IRQS is still the upper limit for the number of IRQs. Both PXA and MMP set NR_IRQS to IRQ_BOARD_START, with IRQ_BOARD_START being the number of IRQs used by the core. In various machine files the nr_irqs field of the ARM machine defintion struct is then set to "IRQ_BOARD_START + NR_BOARD_IRQS". As a result "nr_irqs" will greater then NR_IRQS which then again causes the "allocated_irqs" bitmap in the core irq code to be accessed beyond its size overwriting unrelated data. The core code really misses a sanity check there. This went unnoticed so far as by chance the compiler/linker places data behind that bitmap which gets initialized later on those affected platforms. So the obvious fix would be to add a sanity check in early_irq_init() and break all affected platforms. Though that check wants to be backported to stable as well, which will require to fix all known problematic platforms and probably some more yet not known ones as well. Lots of churn. A way simpler solution is to allocate a slightly larger bitmap and avoid the whole churn w/o breaking anything. Add a few warnings when an arch returns utter crap. Reported-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org # .37 Cc: Haojian Zhuang <haojian.zhuang@marvell.com> Cc: Eric Miao <eric.y.miao@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org>
2011-02-18 00:45:15 +08:00
static DECLARE_BITMAP(irqs_resend, IRQ_BITMAP_BITS);
/*
* Run software resends of IRQ's
*/
static void resend_irqs(struct tasklet_struct *unused)
{
struct irq_desc *desc;
int irq;
while (!bitmap_empty(irqs_resend, nr_irqs)) {
irq = find_first_bit(irqs_resend, nr_irqs);
clear_bit(irq, irqs_resend);
desc = irq_to_desc(irq);
genirq: Prevent NULL pointer dereference in resend_irqs() The following crash was observed: Unable to handle kernel NULL pointer dereference at 0000000000000158 Internal error: Oops: 96000004 [#1] SMP pc : resend_irqs+0x68/0xb0 lr : resend_irqs+0x64/0xb0 ... Call trace: resend_irqs+0x68/0xb0 tasklet_action_common.isra.6+0x84/0x138 tasklet_action+0x2c/0x38 __do_softirq+0x120/0x324 run_ksoftirqd+0x44/0x60 smpboot_thread_fn+0x1ac/0x1e8 kthread+0x134/0x138 ret_from_fork+0x10/0x18 The reason for this is that the interrupt resend mechanism happens in soft interrupt context, which is a asynchronous mechanism versus other operations on interrupts. free_irq() does not take resend handling into account. Thus, the irq descriptor might be already freed before the resend tasklet is executed. resend_irqs() does not check the return value of the interrupt descriptor lookup and derefences the return value unconditionally. 1): __setup_irq irq_startup check_irq_resend // activate softirq to handle resend irq 2): irq_domain_free_irqs irq_free_descs free_desc call_rcu(&desc->rcu, delayed_free_desc) 3): __do_softirq tasklet_action resend_irqs desc = irq_to_desc(irq) desc->handle_irq(desc) // desc is NULL --> Ooops Fix this by adding a NULL pointer check in resend_irqs() before derefencing the irq descriptor. Fixes: a4633adcdbc1 ("[PATCH] genirq: add genirq sw IRQ-retrigger") Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Zhiqiang Liu <liuzhiqiang26@huawei.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1630ae13-5c8e-901e-de09-e740b6a426a7@huawei.com
2019-09-04 20:46:25 +08:00
if (!desc)
continue;
local_irq_disable();
desc->handle_irq(desc);
local_irq_enable();
}
}
/* Tasklet to handle resend: */
static DECLARE_TASKLET(resend_tasklet, resend_irqs);
static int irq_sw_resend(struct irq_desc *desc)
{
unsigned int irq = irq_desc_get_irq(desc);
/*
* Validate whether this interrupt can be safely injected from
* non interrupt context
*/
if (handle_enforce_irqctx(&desc->irq_data))
return -EINVAL;
/*
* If the interrupt is running in the thread context of the parent
* irq we need to be careful, because we cannot trigger it
* directly.
*/
if (irq_settings_is_nested_thread(desc)) {
/*
* If the parent_irq is valid, we retrigger the parent,
* otherwise we do nothing.
*/
if (!desc->parent_irq)
return -EINVAL;
irq = desc->parent_irq;
}
/* Set it pending and activate the softirq: */
set_bit(irq, irqs_resend);
tasklet_schedule(&resend_tasklet);
return 0;
}
#else
static int irq_sw_resend(struct irq_desc *desc)
{
return -EINVAL;
}
#endif
static int try_retrigger(struct irq_desc *desc)
{
if (desc->irq_data.chip->irq_retrigger)
return desc->irq_data.chip->irq_retrigger(&desc->irq_data);
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
return irq_chip_retrigger_hierarchy(&desc->irq_data);
#else
return 0;
#endif
}
/*
* IRQ resend
*
* Is called with interrupts disabled and desc->lock held.
*/
int check_irq_resend(struct irq_desc *desc, bool inject)
{
int err = 0;
/*
* We do not resend level type interrupts. Level type interrupts
* are resent by hardware when they are still active. Clear the
* pending bit so suspend/resume does not get confused.
*/
if (irq_settings_is_level(desc)) {
desc->istate &= ~IRQS_PENDING;
return -EINVAL;
}
if (desc->istate & IRQS_REPLAY)
return -EBUSY;
if (!(desc->istate & IRQS_PENDING) && !inject)
return 0;
desc->istate &= ~IRQS_PENDING;
if (!try_retrigger(desc))
err = irq_sw_resend(desc);
/* If the retrigger was successful, mark it with the REPLAY bit */
if (!err)
desc->istate |= IRQS_REPLAY;
return err;
}
#ifdef CONFIG_GENERIC_IRQ_INJECTION
/**
* irq_inject_interrupt - Inject an interrupt for testing/error injection
* @irq: The interrupt number
*
* This function must only be used for debug and testing purposes!
*
* Especially on x86 this can cause a premature completion of an interrupt
* affinity change causing the interrupt line to become stale. Very
* unlikely, but possible.
*
* The injection can fail for various reasons:
* - Interrupt is not activated
* - Interrupt is NMI type or currently replaying
* - Interrupt is level type
* - Interrupt does not support hardware retrigger and software resend is
* either not enabled or not possible for the interrupt.
*/
int irq_inject_interrupt(unsigned int irq)
{
struct irq_desc *desc;
unsigned long flags;
int err;
/* Try the state injection hardware interface first */
if (!irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, true))
return 0;
/* That failed, try via the resend mechanism */
desc = irq_get_desc_buslock(irq, &flags, 0);
if (!desc)
return -EINVAL;
/*
* Only try to inject when the interrupt is:
* - not NMI type
* - activated
*/
if ((desc->istate & IRQS_NMI) || !irqd_is_activated(&desc->irq_data))
err = -EINVAL;
else
err = check_irq_resend(desc, true);
irq_put_desc_busunlock(desc, flags);
return err;
}
EXPORT_SYMBOL_GPL(irq_inject_interrupt);
#endif