user/sven/linux.git/kernel/trace/trace_printk.c, branch v5.4.235

tracing: Add locked_down checks to the open calls of files created for tracefs

2019-10-13T00:48:06Z

Added various checks on open tracefs calls to see if tracefs is in lockdown mode, and if so, to return -EPERM. Note, the event format files (which are basically standard on all machines) as well as the enabled_functions file (which shows what is currently being traced) are not lockde down. Perhaps they should be, but it seems counter intuitive to lockdown information to help you know if the system has been modified. Link: http://lkml.kernel.org/r/CAHk-=wj7fGPKUspr579Cii-w_y60PtRaiDgKuxVtBAMK0VNNkA@mail.gmail.com Suggested-by: Linus Torvalds Signed-off-by: Steven Rostedt (VMware)

tracing: Trivia spelling fix containerof() -> container_of()

2018-09-26T09:21:00Z

This is the only location on kernel that has wrong spelling of the container_of() helper. Fix it. Signed-off-by: Andy Shevchenko Acked-by: Steven Rostedt (VMware) Signed-off-by: Andy Shevchenko

tracing: Add SPDX License format tags to tracing files

2018-08-16T23:08:06Z

Add the SPDX License header to ease license compliance management. Signed-off-by: Steven Rostedt (VMware)

treewide: Align function definition open/close braces

2018-03-26T09:13:09Z

Some functions definitions have either the initial open brace and/or the closing brace outside of column 1. Move those braces to column 1. This allows various function analyzers like gnu complexity to work properly for these modified functions. Signed-off-by: Joe Perches Acked-by: Andy Shevchenko Acked-by: Paul Moore Acked-by: Alex Deucher Acked-by: Dave Chinner Reviewed-by: Darrick J. Wong Acked-by: Alexandre Belloni Acked-by: Martin K. Petersen Acked-by: Takashi Iwai Acked-by: Mauro Carvalho Chehab Acked-by: Rafael J. Wysocki Acked-by: Nicolin Chen Acked-by: Martin K. Petersen Acked-by: Steven Rostedt (VMware) Signed-off-by: Jiri Kosina

tracing: Handle NULL formats in hold_module_trace_bprintk_format()

2016-06-20T13:46:12Z

If a task uses a non constant string for the format parameter in trace_printk(), then the trace_printk_fmt variable is set to NULL. This variable is then saved in the __trace_printk_fmt section. The function hold_module_trace_bprintk_format() checks to see if duplicate formats are used by modules, and reuses them if so (saves them to the list if it is new). But this function calls lookup_format() that does a strcmp() to the value (which is now NULL) and can cause a kernel oops. This wasn't an issue till 3debb0a9ddb ("tracing: Fix trace_printk() to print when not using bprintk()") which added "__used" to the trace_printk_fmt variable, and before that, the kernel simply optimized it out (no NULL value was saved). The fix is simply to handle the NULL pointer in lookup_format() and have the caller ignore the value if it was NULL. Link: http://lkml.kernel.org/r/1464769870-18344-1-git-send-email-zhengjun.xing@intel.com Reported-by: xingzhen Acked-by: Namhyung Kim Fixes: 3debb0a9ddb ("tracing: Fix trace_printk() to print when not using bprintk()") Cc: stable@vger.kernel.org # v3.5+ Signed-off-by: Steven Rostedt

tracing: Fix trace_printk() to print when not using bprintk()

2016-03-22T22:02:40Z

The trace_printk() code will allocate extra buffers if the compile detects that a trace_printk() is used. To do this, the format of the trace_printk() is saved to the __trace_printk_fmt section, and if that section is bigger than zero, the buffers are allocated (along with a message that this has happened). If trace_printk() uses a format that is not a constant, and thus something not guaranteed to be around when the print happens, the compiler optimizes the fmt out, as it is not used, and the __trace_printk_fmt section is not filled. This means the kernel will not allocate the special buffers needed for the trace_printk() and the trace_printk() will not write anything to the tracing buffer. Adding a "__used" to the variable in the __trace_printk_fmt section will keep it around, even though it is set to NULL. This will keep the string from being printed in the debugfs/tracing/printk_formats section as it is not needed. Reported-by: Vlastimil Babka Fixes: 07d777fe8c398 "tracing: Add percpu buffers for trace_printk()" Cc: stable@vger.kernel.org # v3.5+ Signed-off-by: Steven Rostedt

tracing: Fix setting of start_index in find_next()

2016-01-04T20:22:47Z

When we do cat /sys/kernel/debug/tracing/printk_formats, we hit kernel panic at t_show. general protection fault: 0000 [#1] PREEMPT SMP CPU: 0 PID: 2957 Comm: sh Tainted: G W O 3.14.55-x86_64-01062-gd4acdc7 #2 RIP: 0010:[] [] t_show+0x22/0xe0 RSP: 0000:ffff88002b4ebe80 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000004 RDX: 0000000000000004 RSI: ffffffff81fd26a6 RDI: ffff880032f9f7b1 RBP: ffff88002b4ebe98 R08: 0000000000001000 R09: 000000000000ffec R10: 0000000000000000 R11: 000000000000000f R12: ffff880004d9b6c0 R13: 7365725f6d706400 R14: ffff880004d9b6c0 R15: ffffffff82020570 FS: 0000000000000000(0000) GS:ffff88003aa00000(0063) knlGS:00000000f776bc40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f6c02ff0 CR3: 000000002c2b3000 CR4: 00000000001007f0 Call Trace: [] seq_read+0x2f6/0x3e0 [] vfs_read+0x9b/0x160 [] SyS_read+0x49/0xb0 [] ia32_do_call+0x13/0x13 ---[ end trace 5bd9eb630614861e ]--- Kernel panic - not syncing: Fatal exception When the first time find_next calls find_next_mod_format, it should iterate the trace_bprintk_fmt_list to find the first print format of the module. However in current code, start_index is smaller than *pos at first, and code will not iterate the list. Latter container_of will get the wrong address with former v, which will cause mod_fmt be a meaningless object and so is the returned mod_fmt->fmt. This patch will fix it by correcting the start_index. After fixed, when the first time calls find_next_mod_format, start_index will be equal to *pos, and code will iterate the trace_bprintk_fmt_list to get the right module printk format, so is the returned mod_fmt->fmt. Link: http://lkml.kernel.org/r/5684B900.9000309@intel.com Cc: stable@vger.kernel.org # 3.12+ Fixes: 102c9323c35a8 "tracing: Add __tracepoint_string() to export string pointers" Signed-off-by: Qiu Peiyang Signed-off-by: Steven Rostedt

tracing: Remove access to trace_flags in trace_printk.c

2015-09-30T08:35:18Z

In the effort to move the global trace_flags to the tracing instances, the direct access to trace_flags must be removed from trace_printk.c Instead, add a new trace_printk_enabled boolean that is set by a new access function trace_printk_control(), that will enable or disable trace_printk. Signed-off-by: Steven Rostedt

tracing: Use IS_ERR() check for return value of tracing_init_dentry()

2015-01-22T16:19:49Z

tracing_init_dentry() will soon return NULL as a valid pointer for the top level tracing directroy. NULL can not be used as an error value. Instead, switch to ERR_PTR() and check the return status with IS_ERR(). Signed-off-by: Steven Rostedt

tracing: Remove unneeded includes of debugfs.h and fs.h

2015-01-22T16:19:48Z

The creation of tracing files and directories is for the most part encapsulated in helper functions in trace.c. Other files do not need to include debugfs.h or fs.h, as they may have needed to in the past. Remove them from the files that do not need them. Signed-off-by: Steven Rostedt