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| author | Andrey Konovalov <andreyknvl@google.com> | 2020-06-04 16:46:04 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-04 19:06:20 -0700 |
| commit | 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 (patch) | |
| tree | ce9a72b168d36332af5967cf6fed2877db4da65e /lib/Kconfig.debug | |
| parent | 5fe7042dc0a2e80b4633df20dcd06b93e76e3c31 (diff) | |
| download | linux-5ff3b30ab57da82d8db4f14662a2858cabfbc2c0.tar.gz | |
kcov: collect coverage from interrupts
This change extends kcov remote coverage support to allow collecting coverage from soft interrupts in addition to kernel background threads. To collect coverage from code that is executed in softirq context, a part of that code has to be annotated with kcov_remote_start/stop() in a similar way as how it is done for global kernel background threads. Then the handle used for the annotations has to be passed to the KCOV_REMOTE_ENABLE ioctl. Internally this patch adjusts the __sanitizer_cov_trace_pc() compiler inserted callback to not bail out when called from softirq context. kcov_remote_start/stop() are updated to save/restore the current per task kcov state in a per-cpu area (in case the softirq came when the kernel was already collecting coverage in task context). Coverage from softirqs is collected into pre-allocated per-cpu areas, whose size is controlled by the new CONFIG_KCOV_IRQ_AREA_SIZE. [andreyknvl@google.com: turn current->kcov_softirq into unsigned int to fix objtool warning] Link: http://lkml.kernel.org/r/841c778aa3849c5cb8c3761f56b87ce653a88671.1585233617.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Marco Elver <elver@google.com> Link: http://lkml.kernel.org/r/469bd385c431d050bc38a593296eff4baae50666.1584655448.git.andreyknvl@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/Kconfig.debug')
| -rw-r--r-- | lib/Kconfig.debug | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 0217ed126f77..d07ab3e056cd 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1774,6 +1774,15 @@ config KCOV_INSTRUMENT_ALL filesystem fuzzing with AFL) then you will want to enable coverage for more specific subsets of files, and should say n here. +config KCOV_IRQ_AREA_SIZE + hex "Size of interrupt coverage collection area in words" + depends on KCOV + default 0x40000 + help + KCOV uses preallocated per-cpu areas to collect coverage from + soft interrupts. This specifies the size of those areas in the + number of unsigned long words. + menuconfig RUNTIME_TESTING_MENU bool "Runtime Testing" def_bool y |