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 14:07:57 +00:00
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// SPDX-License-Identifier: GPL-2.0
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2008-05-19 23:53:02 +00:00
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/*
|
2005-04-16 22:20:36 +00:00
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* fault.c: Page fault handlers for the Sparc.
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*
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* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
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* Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
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* Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
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*/
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#include <asm/head.h>
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|
|
#include <linux/string.h>
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#include <linux/types.h>
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|
#include <linux/sched.h>
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|
|
#include <linux/ptrace.h>
|
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|
|
#include <linux/mman.h>
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|
|
#include <linux/threads.h>
|
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|
|
#include <linux/kernel.h>
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|
#include <linux/signal.h>
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#include <linux/mm.h>
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|
#include <linux/smp.h>
|
2010-01-20 11:04:14 +00:00
|
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|
#include <linux/perf_event.h>
|
2005-04-16 22:20:36 +00:00
|
|
|
#include <linux/interrupt.h>
|
2007-05-08 07:27:03 +00:00
|
|
|
#include <linux/kdebug.h>
|
2015-05-11 15:52:11 +00:00
|
|
|
#include <linux/uaccess.h>
|
2005-04-16 22:20:36 +00:00
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|
#include <asm/page.h>
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|
|
#include <asm/openprom.h>
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|
|
#include <asm/oplib.h>
|
2014-04-21 19:39:38 +00:00
|
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#include <asm/setup.h>
|
2005-04-16 22:20:36 +00:00
|
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|
#include <asm/smp.h>
|
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|
#include <asm/traps.h>
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|
|
|
|
2014-04-21 19:39:17 +00:00
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|
#include "mm_32.h"
|
2010-03-01 08:02:23 +00:00
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|
|
2014-04-21 19:39:17 +00:00
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int show_unhandled_signals = 1;
|
2005-04-16 22:20:36 +00:00
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|
2012-05-15 17:02:08 +00:00
|
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static void __noreturn unhandled_fault(unsigned long address,
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struct task_struct *tsk,
|
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struct pt_regs *regs)
|
2005-04-16 22:20:36 +00:00
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{
|
2012-05-15 17:02:08 +00:00
|
|
|
if ((unsigned long) address < PAGE_SIZE) {
|
2005-04-16 22:20:36 +00:00
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printk(KERN_ALERT
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"Unable to handle kernel NULL pointer dereference\n");
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} else {
|
2012-05-15 17:02:08 +00:00
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printk(KERN_ALERT "Unable to handle kernel paging request at virtual address %08lx\n",
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address);
|
2005-04-16 22:20:36 +00:00
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}
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printk(KERN_ALERT "tsk->{mm,active_mm}->context = %08lx\n",
|
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(tsk->mm ? tsk->mm->context : tsk->active_mm->context));
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printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %08lx\n",
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(tsk->mm ? (unsigned long) tsk->mm->pgd :
|
2012-05-15 17:02:08 +00:00
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(unsigned long) tsk->active_mm->pgd));
|
2005-04-16 22:20:36 +00:00
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die_if_kernel("Oops", regs);
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}
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|
2010-03-01 08:02:23 +00:00
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static inline void
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show_signal_msg(struct pt_regs *regs, int sig, int code,
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unsigned long address, struct task_struct *tsk)
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|
{
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if (!unhandled_signal(tsk, sig))
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return;
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if (!printk_ratelimit())
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return;
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|
2017-12-19 21:52:23 +00:00
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printk("%s%s[%d]: segfault at %lx ip %px (rpc %px) sp %px error %x",
|
2010-03-01 08:02:23 +00:00
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task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
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tsk->comm, task_pid_nr(tsk), address,
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(void *)regs->pc, (void *)regs->u_regs[UREG_I7],
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(void *)regs->u_regs[UREG_FP], code);
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print_vma_addr(KERN_CONT " in ", regs->pc);
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printk(KERN_CONT "\n");
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|
}
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static void __do_fault_siginfo(int code, int sig, struct pt_regs *regs,
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unsigned long addr)
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|
{
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if (unlikely(show_unhandled_signals))
|
2018-04-19 21:59:56 +00:00
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show_signal_msg(regs, sig, code,
|
2010-03-01 08:02:23 +00:00
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addr, current);
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|
2019-05-23 16:04:24 +00:00
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force_sig_fault(sig, code, (void __user *) addr, 0);
|
2010-03-01 08:02:23 +00:00
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}
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|
2005-04-16 22:20:36 +00:00
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static unsigned long compute_si_addr(struct pt_regs *regs, int text_fault)
|
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|
|
|
{
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|
unsigned int insn;
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if (text_fault)
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return regs->pc;
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|
2012-05-15 17:02:08 +00:00
|
|
|
if (regs->psr & PSR_PS)
|
2005-04-16 22:20:36 +00:00
|
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insn = *(unsigned int *) regs->pc;
|
2012-05-15 17:02:08 +00:00
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else
|
2005-04-16 22:20:36 +00:00
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|
__get_user(insn, (unsigned int *) regs->pc);
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|
return safe_compute_effective_address(regs, insn);
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|
}
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|
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|
2010-03-01 08:02:23 +00:00
|
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|
static noinline void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
|
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|
|
int text_fault)
|
|
|
|
|
{
|
|
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|
|
unsigned long addr = compute_si_addr(regs, text_fault);
|
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|
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|
|
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|
__do_fault_siginfo(code, sig, regs, addr);
|
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|
}
|
|
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|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
|
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|
unsigned long address)
|
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|
|
|
{
|
|
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|
|
struct vm_area_struct *vma;
|
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|
|
|
struct task_struct *tsk = current;
|
|
|
|
|
struct mm_struct *mm = tsk->mm;
|
|
|
|
|
unsigned int fixup;
|
|
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|
|
unsigned long g2;
|
|
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|
|
int from_user = !(regs->psr & PSR_PS);
|
2018-08-17 22:44:47 +00:00
|
|
|
int code;
|
|
|
|
|
vm_fault_t fault;
|
2020-04-02 04:08:37 +00:00
|
|
|
unsigned int flags = FAULT_FLAG_DEFAULT;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2012-05-15 17:02:08 +00:00
|
|
|
if (text_fault)
|
2005-04-16 22:20:36 +00:00
|
|
|
address = regs->pc;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* We fault-in kernel-space virtual memory on-demand. The
|
|
|
|
|
* 'reference' page table is init_mm.pgd.
|
|
|
|
|
*
|
|
|
|
|
* NOTE! We MUST NOT take any locks for this case. We may
|
|
|
|
|
* be in an interrupt or a critical region, and should
|
|
|
|
|
* only copy the information from the master page table,
|
|
|
|
|
* nothing more.
|
|
|
|
|
*/
|
2011-03-09 21:00:47 +00:00
|
|
|
code = SEGV_MAPERR;
|
2012-05-11 11:35:08 +00:00
|
|
|
if (address >= TASK_SIZE)
|
2005-04-16 22:20:36 +00:00
|
|
|
goto vmalloc_fault;
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|
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|
|
|
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|
|
/*
|
|
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|
|
* If we're in an interrupt or have no user
|
|
|
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|
* context, we must not take the fault..
|
|
|
|
|
*/
|
2015-05-11 15:52:11 +00:00
|
|
|
if (pagefault_disabled() || !mm)
|
2012-05-15 17:02:08 +00:00
|
|
|
goto no_context;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2011-06-27 12:41:57 +00:00
|
|
|
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
|
2010-01-20 11:04:14 +00:00
|
|
|
|
2012-03-26 06:47:54 +00:00
|
|
|
retry:
|
2020-06-09 04:33:25 +00:00
|
|
|
mmap_read_lock(mm);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2012-05-15 17:02:08 +00:00
|
|
|
if (!from_user && address >= PAGE_OFFSET)
|
2005-04-16 22:20:36 +00:00
|
|
|
goto bad_area;
|
|
|
|
|
|
|
|
|
|
vma = find_vma(mm, address);
|
2012-05-15 17:02:08 +00:00
|
|
|
if (!vma)
|
2005-04-16 22:20:36 +00:00
|
|
|
goto bad_area;
|
2012-05-15 17:02:08 +00:00
|
|
|
if (vma->vm_start <= address)
|
2005-04-16 22:20:36 +00:00
|
|
|
goto good_area;
|
2012-05-15 17:02:08 +00:00
|
|
|
if (!(vma->vm_flags & VM_GROWSDOWN))
|
2005-04-16 22:20:36 +00:00
|
|
|
goto bad_area;
|
2012-05-15 17:02:08 +00:00
|
|
|
if (expand_stack(vma, address))
|
2005-04-16 22:20:36 +00:00
|
|
|
goto bad_area;
|
|
|
|
|
/*
|
|
|
|
|
* Ok, we have a good vm_area for this memory access, so
|
|
|
|
|
* we can handle it..
|
|
|
|
|
*/
|
|
|
|
|
good_area:
|
2010-03-01 08:02:23 +00:00
|
|
|
code = SEGV_ACCERR;
|
2012-05-15 17:02:08 +00:00
|
|
|
if (write) {
|
|
|
|
|
if (!(vma->vm_flags & VM_WRITE))
|
2005-04-16 22:20:36 +00:00
|
|
|
goto bad_area;
|
|
|
|
|
} else {
|
|
|
|
|
/* Allow reads even for write-only mappings */
|
2012-05-15 17:02:08 +00:00
|
|
|
if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
|
2005-04-16 22:20:36 +00:00
|
|
|
goto bad_area;
|
|
|
|
|
}
|
|
|
|
|
|
2013-09-12 22:13:39 +00:00
|
|
|
if (from_user)
|
|
|
|
|
flags |= FAULT_FLAG_USER;
|
|
|
|
|
if (write)
|
|
|
|
|
flags |= FAULT_FLAG_WRITE;
|
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
/*
|
|
|
|
|
* If for any reason at all we couldn't handle the fault,
|
|
|
|
|
* make sure we exit gracefully rather than endlessly redo
|
|
|
|
|
* the fault.
|
|
|
|
|
*/
|
2020-08-12 01:38:43 +00:00
|
|
|
fault = handle_mm_fault(vma, address, flags, regs);
|
2012-03-26 06:47:54 +00:00
|
|
|
|
2020-04-02 04:08:06 +00:00
|
|
|
if (fault_signal_pending(fault, regs))
|
2012-03-26 06:47:54 +00:00
|
|
|
return;
|
|
|
|
|
|
2007-07-19 08:47:05 +00:00
|
|
|
if (unlikely(fault & VM_FAULT_ERROR)) {
|
|
|
|
|
if (fault & VM_FAULT_OOM)
|
|
|
|
|
goto out_of_memory;
|
vm: add VM_FAULT_SIGSEGV handling support
The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.
That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works. However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.
In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV. And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.
However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d4514 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space. And user space really
expected SIGSEGV, not SIGBUS.
To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it. They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.
This is the mindless minimal patch to do this. A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.
Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.
Reported-and-tested-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-01-29 18:51:32 +00:00
|
|
|
else if (fault & VM_FAULT_SIGSEGV)
|
|
|
|
|
goto bad_area;
|
2007-07-19 08:47:05 +00:00
|
|
|
else if (fault & VM_FAULT_SIGBUS)
|
|
|
|
|
goto do_sigbus;
|
|
|
|
|
BUG();
|
|
|
|
|
}
|
2012-03-26 06:47:54 +00:00
|
|
|
|
|
|
|
|
if (flags & FAULT_FLAG_ALLOW_RETRY) {
|
|
|
|
|
if (fault & VM_FAULT_RETRY) {
|
2012-10-08 23:32:19 +00:00
|
|
|
flags |= FAULT_FLAG_TRIED;
|
2012-03-26 06:47:54 +00:00
|
|
|
|
2020-06-09 04:33:51 +00:00
|
|
|
/* No need to mmap_read_unlock(mm) as we would
|
2012-03-26 06:47:54 +00:00
|
|
|
* have already released it in __lock_page_or_retry
|
|
|
|
|
* in mm/filemap.c.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
goto retry;
|
|
|
|
|
}
|
2010-01-20 11:04:14 +00:00
|
|
|
}
|
2012-03-26 06:47:54 +00:00
|
|
|
|
2020-06-09 04:33:25 +00:00
|
|
|
mmap_read_unlock(mm);
|
2005-04-16 22:20:36 +00:00
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Something tried to access memory that isn't in our memory map..
|
|
|
|
|
* Fix it, but check if it's kernel or user first..
|
|
|
|
|
*/
|
|
|
|
|
bad_area:
|
2020-06-09 04:33:25 +00:00
|
|
|
mmap_read_unlock(mm);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
|
bad_area_nosemaphore:
|
|
|
|
|
/* User mode accesses just cause a SIGSEGV */
|
2010-03-01 08:02:23 +00:00
|
|
|
if (from_user) {
|
|
|
|
|
do_fault_siginfo(code, SIGSEGV, regs, text_fault);
|
2005-04-16 22:20:36 +00:00
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Is this in ex_table? */
|
|
|
|
|
no_context:
|
|
|
|
|
g2 = regs->u_regs[UREG_G2];
|
2009-01-06 20:52:41 +00:00
|
|
|
if (!from_user) {
|
|
|
|
|
fixup = search_extables_range(regs->pc, &g2);
|
2012-05-15 17:02:08 +00:00
|
|
|
/* Values below 10 are reserved for other things */
|
|
|
|
|
if (fixup > 10) {
|
2005-04-16 22:20:36 +00:00
|
|
|
#ifdef DEBUG_EXCEPTIONS
|
2012-05-15 17:02:08 +00:00
|
|
|
printk("Exception: PC<%08lx> faddr<%08lx>\n",
|
|
|
|
|
regs->pc, address);
|
2005-04-16 22:20:36 +00:00
|
|
|
printk("EX_TABLE: insn<%08lx> fixup<%08x> g2<%08lx>\n",
|
|
|
|
|
regs->pc, fixup, g2);
|
|
|
|
|
#endif
|
|
|
|
|
regs->u_regs[UREG_G2] = g2;
|
|
|
|
|
regs->pc = fixup;
|
|
|
|
|
regs->npc = regs->pc + 4;
|
|
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
}
|
2012-05-15 17:02:08 +00:00
|
|
|
|
|
|
|
|
unhandled_fault(address, tsk, regs);
|
2005-04-16 22:20:36 +00:00
|
|
|
do_exit(SIGKILL);
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* We ran out of memory, or some other thing happened to us that made
|
|
|
|
|
* us unable to handle the page fault gracefully.
|
|
|
|
|
*/
|
|
|
|
|
out_of_memory:
|
2020-06-09 04:33:25 +00:00
|
|
|
mmap_read_unlock(mm);
|
2009-08-03 02:17:15 +00:00
|
|
|
if (from_user) {
|
|
|
|
|
pagefault_out_of_memory();
|
|
|
|
|
return;
|
|
|
|
|
}
|
2005-04-16 22:20:36 +00:00
|
|
|
goto no_context;
|
|
|
|
|
|
|
|
|
|
do_sigbus:
|
2020-06-09 04:33:25 +00:00
|
|
|
mmap_read_unlock(mm);
|
2010-03-01 08:02:23 +00:00
|
|
|
do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, text_fault);
|
2005-04-16 22:20:36 +00:00
|
|
|
if (!from_user)
|
|
|
|
|
goto no_context;
|
|
|
|
|
|
|
|
|
|
vmalloc_fault:
|
|
|
|
|
{
|
|
|
|
|
/*
|
|
|
|
|
* Synchronize this task's top level page-table
|
|
|
|
|
* with the 'reference' page table.
|
|
|
|
|
*/
|
|
|
|
|
int offset = pgd_index(address);
|
|
|
|
|
pgd_t *pgd, *pgd_k;
|
2019-12-05 00:54:20 +00:00
|
|
|
p4d_t *p4d, *p4d_k;
|
|
|
|
|
pud_t *pud, *pud_k;
|
2005-04-16 22:20:36 +00:00
|
|
|
pmd_t *pmd, *pmd_k;
|
|
|
|
|
|
|
|
|
|
pgd = tsk->active_mm->pgd + offset;
|
|
|
|
|
pgd_k = init_mm.pgd + offset;
|
|
|
|
|
|
|
|
|
|
if (!pgd_present(*pgd)) {
|
|
|
|
|
if (!pgd_present(*pgd_k))
|
|
|
|
|
goto bad_area_nosemaphore;
|
|
|
|
|
pgd_val(*pgd) = pgd_val(*pgd_k);
|
|
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
|
2019-12-05 00:54:20 +00:00
|
|
|
p4d = p4d_offset(pgd, address);
|
|
|
|
|
pud = pud_offset(p4d, address);
|
|
|
|
|
pmd = pmd_offset(pud, address);
|
|
|
|
|
|
|
|
|
|
p4d_k = p4d_offset(pgd_k, address);
|
|
|
|
|
pud_k = pud_offset(p4d_k, address);
|
|
|
|
|
pmd_k = pmd_offset(pud_k, address);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
|
if (pmd_present(*pmd) || !pmd_present(*pmd_k))
|
|
|
|
|
goto bad_area_nosemaphore;
|
2012-05-15 17:02:08 +00:00
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
*pmd = *pmd_k;
|
|
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* This always deals with user addresses. */
|
2008-06-05 18:41:51 +00:00
|
|
|
static void force_user_fault(unsigned long address, int write)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
|
|
|
|
struct vm_area_struct *vma;
|
|
|
|
|
struct task_struct *tsk = current;
|
|
|
|
|
struct mm_struct *mm = tsk->mm;
|
2013-09-12 22:13:39 +00:00
|
|
|
unsigned int flags = FAULT_FLAG_USER;
|
2010-03-01 08:02:23 +00:00
|
|
|
int code;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2010-03-01 08:02:23 +00:00
|
|
|
code = SEGV_MAPERR;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2020-06-09 04:33:25 +00:00
|
|
|
mmap_read_lock(mm);
|
2005-04-16 22:20:36 +00:00
|
|
|
vma = find_vma(mm, address);
|
2012-05-15 17:02:08 +00:00
|
|
|
if (!vma)
|
2005-04-16 22:20:36 +00:00
|
|
|
goto bad_area;
|
2012-05-15 17:02:08 +00:00
|
|
|
if (vma->vm_start <= address)
|
2005-04-16 22:20:36 +00:00
|
|
|
goto good_area;
|
2012-05-15 17:02:08 +00:00
|
|
|
if (!(vma->vm_flags & VM_GROWSDOWN))
|
2005-04-16 22:20:36 +00:00
|
|
|
goto bad_area;
|
2012-05-15 17:02:08 +00:00
|
|
|
if (expand_stack(vma, address))
|
2005-04-16 22:20:36 +00:00
|
|
|
goto bad_area;
|
|
|
|
|
good_area:
|
2010-03-01 08:02:23 +00:00
|
|
|
code = SEGV_ACCERR;
|
2012-05-15 17:02:08 +00:00
|
|
|
if (write) {
|
|
|
|
|
if (!(vma->vm_flags & VM_WRITE))
|
2005-04-16 22:20:36 +00:00
|
|
|
goto bad_area;
|
2013-09-12 22:13:39 +00:00
|
|
|
flags |= FAULT_FLAG_WRITE;
|
2005-04-16 22:20:36 +00:00
|
|
|
} else {
|
2012-05-15 17:02:08 +00:00
|
|
|
if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
|
2005-04-16 22:20:36 +00:00
|
|
|
goto bad_area;
|
|
|
|
|
}
|
mm: do page fault accounting in handle_mm_fault
Patch series "mm: Page fault accounting cleanups", v5.
This is v5 of the pf accounting cleanup series. It originates from Gerald
Schaefer's report on an issue a week ago regarding to incorrect page fault
accountings for retried page fault after commit 4064b9827063 ("mm: allow
VM_FAULT_RETRY for multiple times"):
https://lore.kernel.org/lkml/20200610174811.44b94525@thinkpad/
What this series did:
- Correct page fault accounting: we do accounting for a page fault
(no matter whether it's from #PF handling, or gup, or anything else)
only with the one that completed the fault. For example, page fault
retries should not be counted in page fault counters. Same to the
perf events.
- Unify definition of PERF_COUNT_SW_PAGE_FAULTS: currently this perf
event is used in an adhoc way across different archs.
Case (1): for many archs it's done at the entry of a page fault
handler, so that it will also cover e.g. errornous faults.
Case (2): for some other archs, it is only accounted when the page
fault is resolved successfully.
Case (3): there're still quite some archs that have not enabled
this perf event.
Since this series will touch merely all the archs, we unify this
perf event to always follow case (1), which is the one that makes most
sense. And since we moved the accounting into handle_mm_fault, the
other two MAJ/MIN perf events are well taken care of naturally.
- Unify definition of "major faults": the definition of "major
fault" is slightly changed when used in accounting (not
VM_FAULT_MAJOR). More information in patch 1.
- Always account the page fault onto the one that triggered the page
fault. This does not matter much for #PF handlings, but mostly for
gup. More information on this in patch 25.
Patchset layout:
Patch 1: Introduced the accounting in handle_mm_fault(), not enabled.
Patch 2-23: Enable the new accounting for arch #PF handlers one by one.
Patch 24: Enable the new accounting for the rest outliers (gup, iommu, etc.)
Patch 25: Cleanup GUP task_struct pointer since it's not needed any more
This patch (of 25):
This is a preparation patch to move page fault accountings into the
general code in handle_mm_fault(). This includes both the per task
flt_maj/flt_min counters, and the major/minor page fault perf events. To
do this, the pt_regs pointer is passed into handle_mm_fault().
PERF_COUNT_SW_PAGE_FAULTS should still be kept in per-arch page fault
handlers.
So far, all the pt_regs pointer that passed into handle_mm_fault() is
NULL, which means this patch should have no intented functional change.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200707225021.200906-1-peterx@redhat.com
Link: http://lkml.kernel.org/r/20200707225021.200906-2-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12 01:37:44 +00:00
|
|
|
switch (handle_mm_fault(vma, address, flags, NULL)) {
|
2005-04-16 22:20:36 +00:00
|
|
|
case VM_FAULT_SIGBUS:
|
|
|
|
|
case VM_FAULT_OOM:
|
|
|
|
|
goto do_sigbus;
|
|
|
|
|
}
|
2020-06-09 04:33:25 +00:00
|
|
|
mmap_read_unlock(mm);
|
2005-04-16 22:20:36 +00:00
|
|
|
return;
|
|
|
|
|
bad_area:
|
2020-06-09 04:33:25 +00:00
|
|
|
mmap_read_unlock(mm);
|
2010-03-01 08:02:23 +00:00
|
|
|
__do_fault_siginfo(code, SIGSEGV, tsk->thread.kregs, address);
|
2005-04-16 22:20:36 +00:00
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
do_sigbus:
|
2020-06-09 04:33:25 +00:00
|
|
|
mmap_read_unlock(mm);
|
2010-03-01 08:02:23 +00:00
|
|
|
__do_fault_siginfo(BUS_ADRERR, SIGBUS, tsk->thread.kregs, address);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
|
2010-09-24 05:06:47 +00:00
|
|
|
static void check_stack_aligned(unsigned long sp)
|
|
|
|
|
{
|
|
|
|
|
if (sp & 0x7UL)
|
2019-05-23 15:17:27 +00:00
|
|
|
force_sig(SIGILL);
|
2010-09-24 05:06:47 +00:00
|
|
|
}
|
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
void window_overflow_fault(void)
|
|
|
|
|
{
|
|
|
|
|
unsigned long sp;
|
|
|
|
|
|
|
|
|
|
sp = current_thread_info()->rwbuf_stkptrs[0];
|
2012-05-15 17:02:08 +00:00
|
|
|
if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
|
2005-04-16 22:20:36 +00:00
|
|
|
force_user_fault(sp + 0x38, 1);
|
|
|
|
|
force_user_fault(sp, 1);
|
2010-09-24 05:06:47 +00:00
|
|
|
|
|
|
|
|
check_stack_aligned(sp);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
void window_underflow_fault(unsigned long sp)
|
|
|
|
|
{
|
2012-05-15 17:02:08 +00:00
|
|
|
if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
|
2005-04-16 22:20:36 +00:00
|
|
|
force_user_fault(sp + 0x38, 0);
|
|
|
|
|
force_user_fault(sp, 0);
|
2010-09-24 05:06:47 +00:00
|
|
|
|
|
|
|
|
check_stack_aligned(sp);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
void window_ret_fault(struct pt_regs *regs)
|
|
|
|
|
{
|
|
|
|
|
unsigned long sp;
|
|
|
|
|
|
|
|
|
|
sp = regs->u_regs[UREG_FP];
|
2012-05-15 17:02:08 +00:00
|
|
|
if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
|
2005-04-16 22:20:36 +00:00
|
|
|
force_user_fault(sp + 0x38, 0);
|
|
|
|
|
force_user_fault(sp, 0);
|
2010-09-24 05:06:47 +00:00
|
|
|
|
|
|
|
|
check_stack_aligned(sp);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
