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![Greg Kroah-Hartman](/assets/img/avatar_default.png)
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>
484 lines
11 KiB
C
484 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
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*
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*/
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#include <linux/sched/task_stack.h>
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#include <linux/stacktrace.h>
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#include <linux/kallsyms.h>
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#include <linux/seq_file.h>
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#include <linux/spinlock.h>
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#include <linux/uaccess.h>
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#include <linux/ftrace.h>
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#include <linux/module.h>
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#include <linux/sysctl.h>
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#include <linux/init.h>
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#include <asm/setup.h>
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#include "trace.h"
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static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES+1] =
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{ [0 ... (STACK_TRACE_ENTRIES)] = ULONG_MAX };
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unsigned stack_trace_index[STACK_TRACE_ENTRIES];
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/*
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* Reserve one entry for the passed in ip. This will allow
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* us to remove most or all of the stack size overhead
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* added by the stack tracer itself.
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*/
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struct stack_trace stack_trace_max = {
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.max_entries = STACK_TRACE_ENTRIES - 1,
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.entries = &stack_dump_trace[0],
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};
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unsigned long stack_trace_max_size;
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arch_spinlock_t stack_trace_max_lock =
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(arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
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DEFINE_PER_CPU(int, disable_stack_tracer);
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static DEFINE_MUTEX(stack_sysctl_mutex);
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int stack_tracer_enabled;
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static int last_stack_tracer_enabled;
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void stack_trace_print(void)
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{
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long i;
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int size;
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pr_emerg(" Depth Size Location (%d entries)\n"
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" ----- ---- --------\n",
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stack_trace_max.nr_entries);
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for (i = 0; i < stack_trace_max.nr_entries; i++) {
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if (stack_dump_trace[i] == ULONG_MAX)
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break;
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if (i+1 == stack_trace_max.nr_entries ||
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stack_dump_trace[i+1] == ULONG_MAX)
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size = stack_trace_index[i];
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else
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size = stack_trace_index[i] - stack_trace_index[i+1];
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pr_emerg("%3ld) %8d %5d %pS\n", i, stack_trace_index[i],
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size, (void *)stack_dump_trace[i]);
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}
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}
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/*
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* When arch-specific code overrides this function, the following
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* data should be filled up, assuming stack_trace_max_lock is held to
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* prevent concurrent updates.
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* stack_trace_index[]
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* stack_trace_max
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* stack_trace_max_size
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*/
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void __weak
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check_stack(unsigned long ip, unsigned long *stack)
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{
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unsigned long this_size, flags; unsigned long *p, *top, *start;
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static int tracer_frame;
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int frame_size = ACCESS_ONCE(tracer_frame);
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int i, x;
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this_size = ((unsigned long)stack) & (THREAD_SIZE-1);
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this_size = THREAD_SIZE - this_size;
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/* Remove the frame of the tracer */
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this_size -= frame_size;
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if (this_size <= stack_trace_max_size)
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return;
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/* we do not handle interrupt stacks yet */
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if (!object_is_on_stack(stack))
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return;
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/* Can't do this from NMI context (can cause deadlocks) */
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if (in_nmi())
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return;
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local_irq_save(flags);
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arch_spin_lock(&stack_trace_max_lock);
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/* In case another CPU set the tracer_frame on us */
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if (unlikely(!frame_size))
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this_size -= tracer_frame;
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/* a race could have already updated it */
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if (this_size <= stack_trace_max_size)
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goto out;
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stack_trace_max_size = this_size;
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stack_trace_max.nr_entries = 0;
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stack_trace_max.skip = 3;
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save_stack_trace(&stack_trace_max);
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/* Skip over the overhead of the stack tracer itself */
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for (i = 0; i < stack_trace_max.nr_entries; i++) {
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if (stack_dump_trace[i] == ip)
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break;
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}
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/*
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* Some archs may not have the passed in ip in the dump.
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* If that happens, we need to show everything.
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*/
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if (i == stack_trace_max.nr_entries)
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i = 0;
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/*
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* Now find where in the stack these are.
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*/
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x = 0;
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start = stack;
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top = (unsigned long *)
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(((unsigned long)start & ~(THREAD_SIZE-1)) + THREAD_SIZE);
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/*
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* Loop through all the entries. One of the entries may
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* for some reason be missed on the stack, so we may
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* have to account for them. If they are all there, this
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* loop will only happen once. This code only takes place
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* on a new max, so it is far from a fast path.
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*/
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while (i < stack_trace_max.nr_entries) {
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int found = 0;
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stack_trace_index[x] = this_size;
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p = start;
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for (; p < top && i < stack_trace_max.nr_entries; p++) {
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if (stack_dump_trace[i] == ULONG_MAX)
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break;
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/*
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* The READ_ONCE_NOCHECK is used to let KASAN know that
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* this is not a stack-out-of-bounds error.
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*/
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if ((READ_ONCE_NOCHECK(*p)) == stack_dump_trace[i]) {
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stack_dump_trace[x] = stack_dump_trace[i++];
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this_size = stack_trace_index[x++] =
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(top - p) * sizeof(unsigned long);
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found = 1;
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/* Start the search from here */
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start = p + 1;
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/*
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* We do not want to show the overhead
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* of the stack tracer stack in the
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* max stack. If we haven't figured
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* out what that is, then figure it out
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* now.
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*/
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if (unlikely(!tracer_frame)) {
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tracer_frame = (p - stack) *
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sizeof(unsigned long);
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stack_trace_max_size -= tracer_frame;
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}
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}
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}
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if (!found)
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i++;
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}
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stack_trace_max.nr_entries = x;
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for (; x < i; x++)
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stack_dump_trace[x] = ULONG_MAX;
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if (task_stack_end_corrupted(current)) {
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stack_trace_print();
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BUG();
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}
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out:
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arch_spin_unlock(&stack_trace_max_lock);
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local_irq_restore(flags);
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}
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static void
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stack_trace_call(unsigned long ip, unsigned long parent_ip,
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struct ftrace_ops *op, struct pt_regs *pt_regs)
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{
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unsigned long stack;
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preempt_disable_notrace();
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/* no atomic needed, we only modify this variable by this cpu */
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__this_cpu_inc(disable_stack_tracer);
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if (__this_cpu_read(disable_stack_tracer) != 1)
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goto out;
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ip += MCOUNT_INSN_SIZE;
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check_stack(ip, &stack);
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out:
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__this_cpu_dec(disable_stack_tracer);
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/* prevent recursion in schedule */
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preempt_enable_notrace();
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}
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static struct ftrace_ops trace_ops __read_mostly =
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{
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.func = stack_trace_call,
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.flags = FTRACE_OPS_FL_RECURSION_SAFE,
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};
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static ssize_t
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stack_max_size_read(struct file *filp, char __user *ubuf,
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size_t count, loff_t *ppos)
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{
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unsigned long *ptr = filp->private_data;
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char buf[64];
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int r;
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r = snprintf(buf, sizeof(buf), "%ld\n", *ptr);
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if (r > sizeof(buf))
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r = sizeof(buf);
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return simple_read_from_buffer(ubuf, count, ppos, buf, r);
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}
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static ssize_t
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stack_max_size_write(struct file *filp, const char __user *ubuf,
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size_t count, loff_t *ppos)
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{
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long *ptr = filp->private_data;
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unsigned long val, flags;
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int ret;
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ret = kstrtoul_from_user(ubuf, count, 10, &val);
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if (ret)
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return ret;
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local_irq_save(flags);
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/*
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* In case we trace inside arch_spin_lock() or after (NMI),
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* we will cause circular lock, so we also need to increase
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* the percpu disable_stack_tracer here.
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*/
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__this_cpu_inc(disable_stack_tracer);
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arch_spin_lock(&stack_trace_max_lock);
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*ptr = val;
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arch_spin_unlock(&stack_trace_max_lock);
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__this_cpu_dec(disable_stack_tracer);
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local_irq_restore(flags);
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return count;
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}
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static const struct file_operations stack_max_size_fops = {
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.open = tracing_open_generic,
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.read = stack_max_size_read,
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.write = stack_max_size_write,
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.llseek = default_llseek,
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};
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static void *
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__next(struct seq_file *m, loff_t *pos)
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{
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long n = *pos - 1;
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if (n > stack_trace_max.nr_entries || stack_dump_trace[n] == ULONG_MAX)
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return NULL;
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m->private = (void *)n;
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return &m->private;
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}
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static void *
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t_next(struct seq_file *m, void *v, loff_t *pos)
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{
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(*pos)++;
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return __next(m, pos);
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}
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static void *t_start(struct seq_file *m, loff_t *pos)
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{
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local_irq_disable();
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__this_cpu_inc(disable_stack_tracer);
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arch_spin_lock(&stack_trace_max_lock);
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if (*pos == 0)
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return SEQ_START_TOKEN;
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return __next(m, pos);
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}
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static void t_stop(struct seq_file *m, void *p)
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{
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arch_spin_unlock(&stack_trace_max_lock);
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__this_cpu_dec(disable_stack_tracer);
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local_irq_enable();
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}
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static void trace_lookup_stack(struct seq_file *m, long i)
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{
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unsigned long addr = stack_dump_trace[i];
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seq_printf(m, "%pS\n", (void *)addr);
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}
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static void print_disabled(struct seq_file *m)
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{
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seq_puts(m, "#\n"
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"# Stack tracer disabled\n"
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"#\n"
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"# To enable the stack tracer, either add 'stacktrace' to the\n"
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"# kernel command line\n"
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"# or 'echo 1 > /proc/sys/kernel/stack_tracer_enabled'\n"
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"#\n");
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}
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static int t_show(struct seq_file *m, void *v)
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{
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long i;
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int size;
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if (v == SEQ_START_TOKEN) {
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seq_printf(m, " Depth Size Location"
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" (%d entries)\n"
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" ----- ---- --------\n",
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stack_trace_max.nr_entries);
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if (!stack_tracer_enabled && !stack_trace_max_size)
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print_disabled(m);
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return 0;
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}
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i = *(long *)v;
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if (i >= stack_trace_max.nr_entries ||
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stack_dump_trace[i] == ULONG_MAX)
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return 0;
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if (i+1 == stack_trace_max.nr_entries ||
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stack_dump_trace[i+1] == ULONG_MAX)
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size = stack_trace_index[i];
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else
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size = stack_trace_index[i] - stack_trace_index[i+1];
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seq_printf(m, "%3ld) %8d %5d ", i, stack_trace_index[i], size);
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trace_lookup_stack(m, i);
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return 0;
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}
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static const struct seq_operations stack_trace_seq_ops = {
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.start = t_start,
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.next = t_next,
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.stop = t_stop,
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.show = t_show,
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};
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static int stack_trace_open(struct inode *inode, struct file *file)
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{
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return seq_open(file, &stack_trace_seq_ops);
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}
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static const struct file_operations stack_trace_fops = {
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.open = stack_trace_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = seq_release,
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};
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#ifdef CONFIG_DYNAMIC_FTRACE
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static int
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stack_trace_filter_open(struct inode *inode, struct file *file)
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{
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struct ftrace_ops *ops = inode->i_private;
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return ftrace_regex_open(ops, FTRACE_ITER_FILTER,
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inode, file);
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}
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static const struct file_operations stack_trace_filter_fops = {
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.open = stack_trace_filter_open,
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.read = seq_read,
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.write = ftrace_filter_write,
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.llseek = tracing_lseek,
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.release = ftrace_regex_release,
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};
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#endif /* CONFIG_DYNAMIC_FTRACE */
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int
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stack_trace_sysctl(struct ctl_table *table, int write,
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void __user *buffer, size_t *lenp,
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loff_t *ppos)
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{
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int ret;
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mutex_lock(&stack_sysctl_mutex);
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ret = proc_dointvec(table, write, buffer, lenp, ppos);
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if (ret || !write ||
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(last_stack_tracer_enabled == !!stack_tracer_enabled))
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goto out;
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last_stack_tracer_enabled = !!stack_tracer_enabled;
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if (stack_tracer_enabled)
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register_ftrace_function(&trace_ops);
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else
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unregister_ftrace_function(&trace_ops);
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out:
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mutex_unlock(&stack_sysctl_mutex);
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return ret;
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}
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static char stack_trace_filter_buf[COMMAND_LINE_SIZE+1] __initdata;
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static __init int enable_stacktrace(char *str)
|
|
{
|
|
if (strncmp(str, "_filter=", 8) == 0)
|
|
strncpy(stack_trace_filter_buf, str+8, COMMAND_LINE_SIZE);
|
|
|
|
stack_tracer_enabled = 1;
|
|
last_stack_tracer_enabled = 1;
|
|
return 1;
|
|
}
|
|
__setup("stacktrace", enable_stacktrace);
|
|
|
|
static __init int stack_trace_init(void)
|
|
{
|
|
struct dentry *d_tracer;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
if (IS_ERR(d_tracer))
|
|
return 0;
|
|
|
|
trace_create_file("stack_max_size", 0644, d_tracer,
|
|
&stack_trace_max_size, &stack_max_size_fops);
|
|
|
|
trace_create_file("stack_trace", 0444, d_tracer,
|
|
NULL, &stack_trace_fops);
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
trace_create_file("stack_trace_filter", 0444, d_tracer,
|
|
&trace_ops, &stack_trace_filter_fops);
|
|
#endif
|
|
|
|
if (stack_trace_filter_buf[0])
|
|
ftrace_set_early_filter(&trace_ops, stack_trace_filter_buf, 1);
|
|
|
|
if (stack_tracer_enabled)
|
|
register_ftrace_function(&trace_ops);
|
|
|
|
return 0;
|
|
}
|
|
|
|
device_initcall(stack_trace_init);
|