user/sven/linux.git/kernel/debug, branch v5.6.2

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

kdb: Use for_each_console() helper

2020-01-31T17:34:54Z

Replace open coded single-linked list iteration loop with for_each_console() helper in use. Signed-off-by: Andy Shevchenko Signed-off-by: Daniel Thompson

kdb: remove redundant assignment to pointer bp

2020-01-31T17:34:06Z

The point bp is assigned a value that is never read, it is being re-assigned later to bp = &kdb_breakpoints[lowbp] in a for-loop. Remove the redundant assignment. Addresses-Coverity ("Unused value") Signed-off-by: Colin Ian King Link: https://lore.kernel.org/r/20191128130753.181246-1-colin.king@canonical.com Signed-off-by: Daniel Thompson

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

2020-01-31T17:34:03Z

If you switch to a sleeping task with the "pid" command and then type "rd", kdb tells you this: No current kdb registers. You may need to select another task diag: -17: Invalid register name The first message makes sense, but not the second. Fix it by just returning 0 after commands accessing the current registers finish if we've already printed the "No current kdb registers" error. While fixing kdb_rd(), change the function to use "if" rather than "ifdef". It cleans the function up a bit and any modern compiler will have no trouble handling still producing good code. Signed-off-by: Douglas Anderson Link: https://lore.kernel.org/r/20191109111624.5.I121f4c6f0c19266200bf6ef003de78841e5bfc3d@changeid Signed-off-by: Daniel Thompson

kdb: Gid rid of implicit setting of the current task / regs

2020-01-31T17:34:00Z

Some (but not all?) of the kdb backtrace paths would cause the kdb_current_task and kdb_current_regs to remain changed. As discussed in a review of a previous patch [1], this doesn't seem intuitive, so let's fix that. ...but, it turns out that there's actually no longer any reason to set the current task / current regs while backtracing anymore anyway. As of commit 2277b492582d ("kdb: Fix stack crawling on 'running' CPUs that aren't the master") if we're backtracing on a task running on a CPU we ask that CPU to do the backtrace itself. Linux can do that without anything fancy. If we're doing backtrace on a sleeping task we can also do that fine without updating globals. So this patch mostly just turns into deleting a bunch of code. [1] https://lore.kernel.org/r/20191010150735.dhrj3pbjgmjrdpwr@holly.lan Signed-off-by: Douglas Anderson Link: https://lore.kernel.org/r/20191109111624.4.Ibc3d982bbeb9e46872d43973ba808cd4c79537c7@changeid Signed-off-by: Daniel Thompson

kdb: kdb_current_task shouldn't be exported

2020-01-31T17:33:57Z

The kdb_current_task variable has been declared in "kernel/debug/kdb/kdb_private.h" since 2010 when kdb was added to the mainline kernel. This is not a public header. There should be no reason that kdb_current_task should be exported and there are no in-kernel users that need it. Remove the export. Signed-off-by: Douglas Anderson Link: https://lore.kernel.org/r/20191109111623.3.I14b22b5eb15ca8f3812ab33e96621231304dc1f7@changeid Signed-off-by: Daniel Thompson

kdb: kdb_current_regs should be private

2020-01-31T17:33:54Z

As of the patch ("MIPS: kdb: Remove old workaround for backtracing on other CPUs") there is no reason for kdb_current_regs to be in the public "kdb.h". Let's move it next to kdb_current_task. Signed-off-by: Douglas Anderson Link: https://lore.kernel.org/r/20191109111623.2.Iadbfb484e90b557cc4b5ac9890bfca732cd99d77@changeid Signed-off-by: Daniel Thompson

kdb: Tweak escape handling for vi users

2019-10-28T12:08:29Z

Currently if sequences such as "\ehelp\r" are delivered to the console then the h gets eaten by the escape handling code. Since pressing escape becomes something of a nervous twitch for vi users (and that escape doesn't have much effect at a shell prompt) it is more helpful to emit the 'h' than the '\e'. We don't simply choose to emit the final character for all escape sequences since that will do odd things for unsupported escape sequences (in other words we retain the existing behaviour once we see '\e['). Signed-off-by: Daniel Thompson Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20191025073328.643-6-daniel.thompson@linaro.org

kdb: Improve handling of characters from different input sources

2019-10-28T12:08:10Z

Currently if an escape timer is interrupted by a character from a different input source then the new character is discarded and the function returns '\e' (which will be discarded by the level above). It is hard to see why this would ever be the desired behaviour. Fix this to return the new character rather than the '\e'. This is a bigger refactor than might be expected because the new character needs to go through escape sequence detection. Signed-off-by: Daniel Thompson Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20191025073328.643-5-daniel.thompson@linaro.org

kdb: Remove special case logic from kdb_read()

2019-10-28T12:07:57Z

kdb_read() contains special case logic to force it exit after reading a single character. We can remove all the special case logic by directly calling the function to read a single character instead. This also allows us to tidy up the function prototype which, because it now matches getchar(), we can also rename in order to make its role clearer. This does involve some extra code to handle btaprompt properly but we don't mind the new lines of code here because the old code had some interesting problems (bad newline handling, treating unexpected characters like ). Signed-off-by: Daniel Thompson Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/20191025073328.643-4-daniel.thompson@linaro.org