linux/kernel/debug/kdb, branch v5.8-rc2

maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault

2020-06-17T17:57:41Z

Better describe what these functions do. Suggested-by: Linus Torvalds Signed-off-by: Christoph Hellwig Signed-off-by: Linus Torvalds

kernel: rename show_stack_loglvl() => show_stack()

2020-06-09T16:39:13Z

Now the last users of show_stack() got converted to use an explicit log level, show_stack_loglvl() can drop it's redundant suffix and become once again well known show_stack(). Signed-off-by: Dmitry Safonov Signed-off-by: Andrew Morton Link: http://lkml.kernel.org/r/20200418201944.482088-51-dima@arista.com Signed-off-by: Linus Torvalds

kdb: don't play with console_loglevel

2020-06-09T16:39:12Z

Print the stack trace with KERN_EMERG - it should be always visible. Playing with console_loglevel is a bad idea as there may be more messages printed than wanted. Also the stack trace might be not printed at all if printk() was deferred and console_loglevel was raised back before the trace got flushed. Unfortunately, after rebasing on commit 2277b492582d ("kdb: Fix stack crawling on 'running' CPUs that aren't the master"), kdb_show_stack() uses now kdb_dump_stack_on_cpu(), which for now won't be converted as it uses dump_stack() instead of show_stack(). Convert for now the branch that uses show_stack() and remove console_loglevel exercise from that case. Signed-off-by: Dmitry Safonov Signed-off-by: Andrew Morton Reviewed-by: Douglas Anderson Acked-by: Daniel Thompson Cc: Jason Wessel Link: http://lkml.kernel.org/r/20200418201944.482088-48-dima@arista.com Signed-off-by: Linus Torvalds

kdb: Remove the misfeature 'KDBFLAGS'

2020-06-02T14:15:46Z

Currently, 'KDBFLAGS' is an internal variable of kdb, it is combined by 'KDBDEBUG' and state flags. It will be shown only when 'KDBDEBUG' is set, and the user can define an environment variable named 'KDBFLAGS' too. These are puzzling indeed. After communication with Daniel, it seems that 'KDBFLAGS' is a misfeature. So let's replace 'KDBFLAGS' with 'KDBDEBUG' to just show the value we wrote into. After this modification, we can use `md4c1 kdb_flags` instead, to observe the state flags. Suggested-by: Daniel Thompson Signed-off-by: Wei Li Link: https://lore.kernel.org/r/20200521072125.21103-1-liwei391@huawei.com [daniel.thompson@linaro.org: Make kdb_flags unsigned to avoid arithmetic right shift] Signed-off-by: Daniel Thompson

kdb: Cleanup math with KDB_CMD_HISTORY_COUNT

2020-06-02T14:15:46Z

From code inspection the math in handle_ctrl_cmd() looks super sketchy because it subjects -1 from cmdptr and then does a "% KDB_CMD_HISTORY_COUNT". It turns out that this code works because "cmdptr" is unsigned and KDB_CMD_HISTORY_COUNT is a nice power of 2. Let's make this a little less sketchy. This patch should be a no-op. Signed-off-by: Douglas Anderson Link: https://lore.kernel.org/r/20200507161125.1.I2cce9ac66e141230c3644b8174b6c15d4e769232@changeid Reviewed-by: Sumit Garg Signed-off-by: Daniel Thompson

Merge tag 'spdx-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx

2020-04-03T20:12:26Z

Pull SPDX updates from Greg KH: "Here are three SPDX patches for 5.7-rc1. One fixes up the SPDX tag for a single driver, while the other two go through the tree and add SPDX tags for all of the .gitignore files as needed. Nothing too complex, but you will get a merge conflict with your current tree, that should be trivial to handle (one file modified by two things, one file deleted.) All three of these have been in linux-next for a while, with no reported issues other than the merge conflict" * tag 'spdx-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx: ASoC: MT6660: make spdxcheck.py happy .gitignore: add SPDX License Identifier .gitignore: remove too obvious comments

kdb: Censor attempts to set PROMPT without ENABLE_MEM_READ

2020-04-01T15:59:11Z

Currently the PROMPT variable could be abused to provoke the printf() machinery to read outside the current stack frame. Normally this doesn't matter becaues md is already a much better tool for reading from memory. However the md command can be disabled by not setting KDB_ENABLE_MEM_READ. Let's also prevent PROMPT from being modified in these circumstances. Whilst adding a comment to help future code reviewers we also remove the #ifdef where PROMPT in consumed. There is no problem passing an unused (0) to snprintf when !CONFIG_SMP. argument Reported-by: Wang Xiayang Signed-off-by: Daniel Thompson Reviewed-by: Douglas Anderson

kdb: Eliminate strncpy() warnings by replacing with strscpy()

2020-04-01T15:59:02Z

Currently the code to manage the kdb history buffer uses strncpy() to copy strings to/and from the history and exhibits the classic "but nobody ever told me that strncpy() doesn't always terminate strings" bug. Modern gcc compilers recognise this bug and issue a warning. In reality these calls will only abridge the copied string if kdb_read() has *already* overflowed the command buffer. Thus the use of counted copies here is only used to reduce the secondary effects of a bug elsewhere in the code. Therefore transitioning these calls into strscpy() (without checking the return code) is appropriate. Signed-off-by: Daniel Thompson Reviewed-by: Douglas Anderson

.gitignore: add SPDX License Identifier

2020-03-25T10:50:48Z

Add SPDX License Identifier to all .gitignore files. Signed-off-by: Masahiro Yamada Signed-off-by: Greg Kroah-Hartman

Revert "kdb: Get rid of confusing diag msg from "rd" if current task has no regs"

2020-02-06T11:40:09Z

This reverts commit bbfceba15f8d1260c328a254efc2b3f2deae4904. When DBG_MAX_REG_NUM is zero then a number of symbols are conditionally defined. It is therefore not possible to check it using C expressions. Reported-by: Anatoly Pugachev Acked-by: Doug Anderson Signed-off-by: Daniel Thompson