linux/kernel/trace/trace_kdb.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 14:07:57 +00:00
// SPDX-License-Identifier: GPL-2.0
/*
* kdb helper for dumping the ftrace buffer
*
* Copyright (C) 2010 Jason Wessel <jason.wessel@windriver.com>
*
* ftrace_dump_buf based on ftrace_dump:
* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
* Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
*
*/
#include <linux/init.h>
#include <linux/kgdb.h>
#include <linux/kdb.h>
#include <linux/ftrace.h>
#include "trace.h"
#include "trace_output.h"
static void ftrace_dump_buf(int skip_lines, long cpu_file)
{
/* use static because iter can be a bit big for the stack */
static struct trace_iterator iter;
tracing: kdb: Fix kernel panic during ftdump Currently kdb's ftdump command unconditionally crashes due to a null pointer de-reference whenever the command is run. This in turn causes the kernel to panic. The abridged stacktrace (gathered with ARCH=arm) is: --- cut here --- [<c09535ac>] (panic) from [<c02132dc>] (die+0x264/0x440) [<c02132dc>] (die) from [<c0952eb8>] (__do_kernel_fault.part.11+0x74/0x84) [<c0952eb8>] (__do_kernel_fault.part.11) from [<c021f954>] (do_page_fault+0x1d0/0x3c4) [<c021f954>] (do_page_fault) from [<c020846c>] (do_DataAbort+0x48/0xac) [<c020846c>] (do_DataAbort) from [<c0213c58>] (__dabt_svc+0x38/0x60) Exception stack(0xc0deba88 to 0xc0debad0) ba80: e8c29180 00000001 e9854304 e9854300 c0f567d8 c0df2580 baa0: 00000000 00000000 00000000 c0f117b8 c0e3a3c0 c0debb0c 00000000 c0debad0 bac0: 0000672e c02f4d60 60000193 ffffffff [<c0213c58>] (__dabt_svc) from [<c02f4d60>] (kdb_ftdump+0x1e4/0x3d8) [<c02f4d60>] (kdb_ftdump) from [<c02ce328>] (kdb_parse+0x2b8/0x698) [<c02ce328>] (kdb_parse) from [<c02ceef0>] (kdb_main_loop+0x52c/0x784) [<c02ceef0>] (kdb_main_loop) from [<c02d1b0c>] (kdb_stub+0x238/0x490) --- cut here --- The NULL deref occurs due to the initialized use of struct trace_iter's buffer_iter member. This is a regression, albeit a fairly elderly one. It was introduced by commit 6d158a813efc ("tracing: Remove NR_CPUS array from trace_iterator"). This patch solves this by providing a collection of ring_buffer_iter(s) and using this to initialize buffer_iter. Note that static allocation is used solely because the trace_iter itself is also static allocated. Static allocation also means that we have to NULL-ify the pointer during cleanup to avoid use-after-free problems. Link: http://lkml.kernel.org/r/1415277716-19419-2-git-send-email-daniel.thompson@linaro.org Cc: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-06 12:41:55 +00:00
static struct ring_buffer_iter *buffer_iter[CONFIG_NR_CPUS];
struct trace_array *tr;
unsigned int old_userobj;
int cnt = 0, cpu;
trace_init_global_iter(&iter);
tracing: kdb: Fix kernel panic during ftdump Currently kdb's ftdump command unconditionally crashes due to a null pointer de-reference whenever the command is run. This in turn causes the kernel to panic. The abridged stacktrace (gathered with ARCH=arm) is: --- cut here --- [<c09535ac>] (panic) from [<c02132dc>] (die+0x264/0x440) [<c02132dc>] (die) from [<c0952eb8>] (__do_kernel_fault.part.11+0x74/0x84) [<c0952eb8>] (__do_kernel_fault.part.11) from [<c021f954>] (do_page_fault+0x1d0/0x3c4) [<c021f954>] (do_page_fault) from [<c020846c>] (do_DataAbort+0x48/0xac) [<c020846c>] (do_DataAbort) from [<c0213c58>] (__dabt_svc+0x38/0x60) Exception stack(0xc0deba88 to 0xc0debad0) ba80: e8c29180 00000001 e9854304 e9854300 c0f567d8 c0df2580 baa0: 00000000 00000000 00000000 c0f117b8 c0e3a3c0 c0debb0c 00000000 c0debad0 bac0: 0000672e c02f4d60 60000193 ffffffff [<c0213c58>] (__dabt_svc) from [<c02f4d60>] (kdb_ftdump+0x1e4/0x3d8) [<c02f4d60>] (kdb_ftdump) from [<c02ce328>] (kdb_parse+0x2b8/0x698) [<c02ce328>] (kdb_parse) from [<c02ceef0>] (kdb_main_loop+0x52c/0x784) [<c02ceef0>] (kdb_main_loop) from [<c02d1b0c>] (kdb_stub+0x238/0x490) --- cut here --- The NULL deref occurs due to the initialized use of struct trace_iter's buffer_iter member. This is a regression, albeit a fairly elderly one. It was introduced by commit 6d158a813efc ("tracing: Remove NR_CPUS array from trace_iterator"). This patch solves this by providing a collection of ring_buffer_iter(s) and using this to initialize buffer_iter. Note that static allocation is used solely because the trace_iter itself is also static allocated. Static allocation also means that we have to NULL-ify the pointer during cleanup to avoid use-after-free problems. Link: http://lkml.kernel.org/r/1415277716-19419-2-git-send-email-daniel.thompson@linaro.org Cc: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-06 12:41:55 +00:00
iter.buffer_iter = buffer_iter;
tr = iter.tr;
for_each_tracing_cpu(cpu) {
atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
}
old_userobj = tr->trace_flags;
/* don't look at user memory in panic mode */
tr->trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
kdb_printf("Dumping ftrace buffer:\n");
/* reset all but tr, trace, and overruns */
memset(&iter.seq, 0,
sizeof(struct trace_iterator) -
offsetof(struct trace_iterator, seq));
iter.iter_flags |= TRACE_FILE_LAT_FMT;
iter.pos = -1;
if (cpu_file == RING_BUFFER_ALL_CPUS) {
for_each_tracing_cpu(cpu) {
iter.buffer_iter[cpu] =
ring_buffer_read_prepare(iter.trace_buffer->buffer, cpu);
ring_buffer_read_start(iter.buffer_iter[cpu]);
tracing_iter_reset(&iter, cpu);
}
} else {
iter.cpu_file = cpu_file;
iter.buffer_iter[cpu_file] =
ring_buffer_read_prepare(iter.trace_buffer->buffer, cpu_file);
ring_buffer_read_start(iter.buffer_iter[cpu_file]);
tracing_iter_reset(&iter, cpu_file);
}
while (trace_find_next_entry_inc(&iter)) {
if (!cnt)
kdb_printf("---------------------------------\n");
cnt++;
if (!skip_lines) {
print_trace_line(&iter);
trace_printk_seq(&iter.seq);
} else {
skip_lines--;
}
if (KDB_FLAG(CMD_INTERRUPT))
goto out;
}
if (!cnt)
kdb_printf(" (ftrace buffer empty)\n");
else
kdb_printf("---------------------------------\n");
out:
tr->trace_flags = old_userobj;
for_each_tracing_cpu(cpu) {
atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
}
tracing: kdb: Fix kernel panic during ftdump Currently kdb's ftdump command unconditionally crashes due to a null pointer de-reference whenever the command is run. This in turn causes the kernel to panic. The abridged stacktrace (gathered with ARCH=arm) is: --- cut here --- [<c09535ac>] (panic) from [<c02132dc>] (die+0x264/0x440) [<c02132dc>] (die) from [<c0952eb8>] (__do_kernel_fault.part.11+0x74/0x84) [<c0952eb8>] (__do_kernel_fault.part.11) from [<c021f954>] (do_page_fault+0x1d0/0x3c4) [<c021f954>] (do_page_fault) from [<c020846c>] (do_DataAbort+0x48/0xac) [<c020846c>] (do_DataAbort) from [<c0213c58>] (__dabt_svc+0x38/0x60) Exception stack(0xc0deba88 to 0xc0debad0) ba80: e8c29180 00000001 e9854304 e9854300 c0f567d8 c0df2580 baa0: 00000000 00000000 00000000 c0f117b8 c0e3a3c0 c0debb0c 00000000 c0debad0 bac0: 0000672e c02f4d60 60000193 ffffffff [<c0213c58>] (__dabt_svc) from [<c02f4d60>] (kdb_ftdump+0x1e4/0x3d8) [<c02f4d60>] (kdb_ftdump) from [<c02ce328>] (kdb_parse+0x2b8/0x698) [<c02ce328>] (kdb_parse) from [<c02ceef0>] (kdb_main_loop+0x52c/0x784) [<c02ceef0>] (kdb_main_loop) from [<c02d1b0c>] (kdb_stub+0x238/0x490) --- cut here --- The NULL deref occurs due to the initialized use of struct trace_iter's buffer_iter member. This is a regression, albeit a fairly elderly one. It was introduced by commit 6d158a813efc ("tracing: Remove NR_CPUS array from trace_iterator"). This patch solves this by providing a collection of ring_buffer_iter(s) and using this to initialize buffer_iter. Note that static allocation is used solely because the trace_iter itself is also static allocated. Static allocation also means that we have to NULL-ify the pointer during cleanup to avoid use-after-free problems. Link: http://lkml.kernel.org/r/1415277716-19419-2-git-send-email-daniel.thompson@linaro.org Cc: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-06 12:41:55 +00:00
for_each_tracing_cpu(cpu) {
if (iter.buffer_iter[cpu]) {
ring_buffer_read_finish(iter.buffer_iter[cpu]);
tracing: kdb: Fix kernel panic during ftdump Currently kdb's ftdump command unconditionally crashes due to a null pointer de-reference whenever the command is run. This in turn causes the kernel to panic. The abridged stacktrace (gathered with ARCH=arm) is: --- cut here --- [<c09535ac>] (panic) from [<c02132dc>] (die+0x264/0x440) [<c02132dc>] (die) from [<c0952eb8>] (__do_kernel_fault.part.11+0x74/0x84) [<c0952eb8>] (__do_kernel_fault.part.11) from [<c021f954>] (do_page_fault+0x1d0/0x3c4) [<c021f954>] (do_page_fault) from [<c020846c>] (do_DataAbort+0x48/0xac) [<c020846c>] (do_DataAbort) from [<c0213c58>] (__dabt_svc+0x38/0x60) Exception stack(0xc0deba88 to 0xc0debad0) ba80: e8c29180 00000001 e9854304 e9854300 c0f567d8 c0df2580 baa0: 00000000 00000000 00000000 c0f117b8 c0e3a3c0 c0debb0c 00000000 c0debad0 bac0: 0000672e c02f4d60 60000193 ffffffff [<c0213c58>] (__dabt_svc) from [<c02f4d60>] (kdb_ftdump+0x1e4/0x3d8) [<c02f4d60>] (kdb_ftdump) from [<c02ce328>] (kdb_parse+0x2b8/0x698) [<c02ce328>] (kdb_parse) from [<c02ceef0>] (kdb_main_loop+0x52c/0x784) [<c02ceef0>] (kdb_main_loop) from [<c02d1b0c>] (kdb_stub+0x238/0x490) --- cut here --- The NULL deref occurs due to the initialized use of struct trace_iter's buffer_iter member. This is a regression, albeit a fairly elderly one. It was introduced by commit 6d158a813efc ("tracing: Remove NR_CPUS array from trace_iterator"). This patch solves this by providing a collection of ring_buffer_iter(s) and using this to initialize buffer_iter. Note that static allocation is used solely because the trace_iter itself is also static allocated. Static allocation also means that we have to NULL-ify the pointer during cleanup to avoid use-after-free problems. Link: http://lkml.kernel.org/r/1415277716-19419-2-git-send-email-daniel.thompson@linaro.org Cc: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-06 12:41:55 +00:00
iter.buffer_iter[cpu] = NULL;
}
}
}
/*
* kdb_ftdump - Dump the ftrace log buffer
*/
static int kdb_ftdump(int argc, const char **argv)
{
int skip_lines = 0;
long cpu_file;
char *cp;
if (argc > 2)
return KDB_ARGCOUNT;
if (argc) {
skip_lines = simple_strtol(argv[1], &cp, 0);
if (*cp)
skip_lines = 0;
}
if (argc == 2) {
cpu_file = simple_strtol(argv[2], &cp, 0);
if (*cp || cpu_file >= NR_CPUS || cpu_file < 0 ||
!cpu_online(cpu_file))
return KDB_BADINT;
} else {
cpu_file = RING_BUFFER_ALL_CPUS;
}
kdb_trap_printk++;
ftrace_dump_buf(skip_lines, cpu_file);
kdb_trap_printk--;
return 0;
}
static __init int kdb_ftrace_register(void)
{
kdb_register_flags("ftdump", kdb_ftdump, "[skip_#lines] [cpu]",
"Dump ftrace log", 0, KDB_ENABLE_ALWAYS_SAFE);
return 0;
}
late_initcall(kdb_ftrace_register);