kernel/arch/s390/include/asm/stacktrace.h, branch linux-6.2.y

s390/entry: sort out physical vs virtual pointers usage in sie64a

2022-10-26T12:27:41Z

Fix virtual vs physical address confusion (which currently are the same). sie_block is accessed in entry.S and passed it to hardware, which is why both its physical and virtual address are needed. To avoid every caller having to do the virtual-physical conversion, add a new function sie64a() which converts the virtual address to physical. Signed-off-by: Nico Boehr Reviewed-by: Alexander Gordeev Reviewed-by: Claudio Imbrenda Link: https://lore.kernel.org/r/20221020143159.294605-3-nrb@linux.ibm.com Message-Id: <20221020143159.294605-3-nrb@linux.ibm.com> Signed-off-by: Janosch Frank

s390/stack: add union to reflect kvm stack slot usages

2022-06-01T10:03:17Z

Add a union which describes how the empty stack slots are being used by kvm and perf. This should help to avoid another bug like the one which was fixed with commit c9bfb460c3e4 ("s390/perf: obtain sie_block from the right address"). Reviewed-by: Nico Boehr Tested-by: Nico Boehr Signed-off-by: Heiko Carstens

s390/stack: merge empty stack frame slots

2022-06-01T10:03:17Z

Merge empty1 and empty2 arrays within the stack frame to one single array. This is possible since with commit 42b01a553a56 ("s390: always use the packed stack layout") the alternative stack frame layout is gone. Reviewed-by: Nico Boehr Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens

s390: current_stack_pointer shouldn't be a function

2022-04-12T09:56:08Z

s390 defines current_stack_pointer as function while all other architectures use 'register unsigned long asm(""). This make codes like the following from check_stack_object() fail: if (IS_ENABLED(CONFIG_STACK_GROWSUP)) { if ((void *)current_stack_pointer < obj + len) return BAD_STACK; } else { if (obj < (void *)current_stack_pointer) return BAD_STACK; } because this would compare the address of current_stack_pointer() and not the stackpointer value. Reported-by: Karsten Graul Fixes: 2792d84e6da5 ("usercopy: Check valid lifetime via stack depth") Cc: Kees Cook Cc: Vasily Gorbik Cc: Alexander Gordeev Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Heiko Carstens

s390: always use the packed stack layout

2022-03-01T20:05:09Z

-mpacked-stack option has been supported by both minimum gcc and clang versions for a while. With commit e2bc3e91d91e ("scripts/min-tool-version.sh: Raise minimum clang version to 13.0.0 for s390") minimum clang version now also supports a combination of flags -mpacked-stack -mbackchain -pg -mfentry and fulfills all requirements to always enable the packed stack layout. Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/unwind: use current_frame_address() to unwind current task

2021-09-07T11:38:27Z

current_stack_pointer() simply returns current value of %r15. If current_stack_pointer() caller allocates stack (which is the case in unwind code) %r15 points to a stack frame allocated for callees, meaning current_stack_pointer() caller (e.g. stack_trace_save) will end up in the stacktrace. This is not expected by stack_trace_save*() callers and causes problems. current_frame_address() on the other hand returns function stack frame address, which matches %r15 upon function invocation. Using it in get_stack_pointer() makes it more aligned with x86 implementation (according to BACKTRACE_SELF_TEST output) and meets stack_trace_save*() caller's expectations, notably KCSAN. Also make sure unwind_start is always inlined. Reported-by: Nathan Chancellor Suggested-by: Marco Elver Signed-off-by: Vasily Gorbik Tested-by: Marco Elver Tested-by: Nathan Chancellor Link: https://lore.kernel.org/r/patch.git-04dd26be3043.your-ad-here.call-01630504868-ext-6188@work.hours Signed-off-by: Heiko Carstens

s390: rename CALL_ON_STACK_NORETURN() to call_on_stack_noreturn()

2021-07-08T20:12:18Z

Lower case matches the call_on_stack() macro and is easier to read. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: add type checking to CALL_ON_STACK_NORETURN() macro

2021-07-08T20:12:18Z

Make sure the to be called function takes no arguments (and returns void). Otherwise usage of CALL_ON_STACK_NORETURN() would generate broken code. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: remove old CALL_ON_STACK() macro

2021-07-08T20:12:18Z

Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: introduce proper type handling call_on_stack() macro

2021-07-08T20:12:17Z

The existing CALL_ON_STACK() macro allows for subtle bugs: - There is no type checking of the function that is being called. That is: missing or too many arguments do not cause any compile error or warning. The same is true if the return type of the called function changes. This can lead to quite random bugs. - Sign and zero extension of arguments is missing. Given that the s390 C ABI requires that the caller of a function performs proper sign and zero extension this can also lead to subtle bugs. - If arguments to the CALL_ON_STACK() macros contain functions calls register corruption can happen due to register asm constructs being used. Therefore introduce a new call_on_stack() macro which is supposed to fix all these problems. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik