lwn.git/arch/s390/kernel/dumpstack.c, branch v5.2-rc4

s390/unwind: introduce stack unwind API

2019-05-02T11:54:11+00:00

Rework the dump_trace() stack unwinder interface to support different unwinding algorithms. The new interface looks like this: struct unwind_state state; unwind_for_each_frame(&state, task, regs, start_stack) do_something(state.sp, state.ip, state.reliable); The unwind_bc.c file contains the implementation for the classic back-chain unwinder. One positive side effect of the new code is it now handles ftraced functions gracefully. It prints the real name of the return function instead of 'return_to_handler'. Signed-off-by: Martin Schwidefsky

s390/dumpstack: print psw mask and address again

2018-10-10T05:37:20+00:00

With pointer obfuscation the output of show_registers() became quite useless: Krnl PSW : (____ptrval____) (____ptrval____) (__list_add_valid+0x98/0xa8) In order to print the psw mask and address use %px instead of %p. And the output looks again like this: Krnl PSW : 0404d00180000000 00000000007c0dd0 (__list_add_valid+0x98/0xa8) Reviewed-by: Martin Schwidefsky Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/dumpstack: disable __dump_trace kasan instrumentation

2018-10-09T09:21:27+00:00

Walking async_stack produces false positives. Disable __dump_trace function instrumentation for now. Signed-off-by: Vasily Gorbik Signed-off-by: Martin Schwidefsky

s390: unify stack size definitions

2018-10-09T09:20:58+00:00

Remove STACK_ORDER and STACK_SIZE in favour of identical THREAD_SIZE_ORDER and THREAD_SIZE definitions. THREAD_SIZE and THREAD_SIZE_ORDER naming is misleading since it is used as general kernel stack size information. But both those definitions are used in the common code and throughout architectures specific code, so changing the naming is problematic. Reviewed-by: Martin Schwidefsky Signed-off-by: Vasily Gorbik Signed-off-by: Martin Schwidefsky

s390: add support for virtually mapped kernel stacks

2018-10-09T09:20:57+00:00

With virtually mapped kernel stacks the kernel stack overflow detection is now fault based, every stack has a guard page in the vmalloc space. The panic_stack is renamed to nodat_stack and is used for all function that need to run without DAT, e.g. memcpy_real or do_start_kdump. The main effect is a reduction in the kernel image size as with vmap stacks the old style overflow checking that adds two instructions per function is not needed anymore. Result from bloat-o-meter: add/remove: 20/1 grow/shrink: 13/26854 up/down: 2198/-216240 (-214042) In regard to performance the micro-benchmark for fork has a hit of a few microseconds, allocating 4 pages in vmalloc space is more expensive compare to an order-2 page allocation. But with real workload I could not find a noticeable difference. Acked-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390: kernel: add SPDX identifiers to the remaining files

2017-11-24T14:37:12+00:00

It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the arch/s390/kernel/ files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Signed-off-by: Greg Kroah-Hartman Signed-off-by: Martin Schwidefsky

s390/mm: use new mm defines instead of magic values

2017-07-26T06:25:09+00:00

Reviewed-by: Martin Schwidefsky Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390: rename struct psw_bits members

2017-06-12T14:26:02+00:00

Rename a couple of the struct psw_bits members so it is more obvious for what they are good. Initially I thought using the single character names from the PoP would be sufficient and obvious, but admittedly that is not true. The current implementation is not easy to use, if one has to look into the source file to figure out which member represents the 'per' bit (which is the 'r' member). Therefore rename the members to sane names that are identical to the uapi psw mask defines: r -> per i -> io e -> ext t -> dat m -> mcheck w -> wait p -> pstate Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/dumpstack: remove raw stack dump

2017-06-12T14:26:01+00:00

Remove raw stack dumps that are printed before call traces in case of a warning, or the 'l' sysrq trigger (show a stack backtrace for all active CPUs). Besides that a raw stack dump should not be shown for the 'l' sysrq trigger the value of the dump is close to zero. That's also why we don't print it in case of a panic since ages anymore. That this is still printed on warnings is just a leftover. So get rid of this completely. The following won't be printed anymore with this change: Stack: 00000000bbc4fbc8 00000000bbc4fc58 0000000000000003 0000000000000000 00000000bbc4fcf8 00000000bbc4fc70 00000000bbc4fc70 0000000000000020 000000007fe00098 00000000bfe8be00 00000000bbc4fe94 000000000000000a 000000000000000c 00000000bbc4fcc0 0000000000000000 0000000000000000 000000000095b930 0000000000113366 00000000bbc4fc58 00000000bbc4fca0 Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:36+00:00

We are going to split out of , which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder file that just maps to to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar