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authorHeiko Carstens <hca@linux.ibm.com>2023-10-30 18:50:46 +0300
committerVasily Gorbik <gor@linux.ibm.com>2023-11-06 00:34:57 +0300
commit504b73d00a55a68c0d1bb0e7c12e56e5f908e906 (patch)
tree6e108d264f5385eb8038718e4ab861c88f2da5e6 /arch/s390/include
parente14aec23025eeb1f2159ba34dbc1458467c4c347 (diff)
downloadlinux-504b73d00a55a68c0d1bb0e7c12e56e5f908e906.tar.xz
s390/perf: implement perf_callchain_user()
Daan De Meyer and Neal Gompa reported that s390 does not support perf user stack unwinding. This was never implemented since this requires user space to be compiled with the -mbackchain compile option, which until now no distribution did. However this is going to change with Fedora. Therefore provide a perf_callchain_user() implementation. Note that due to the way s390 sets up stack frames the provided call chains can contain invalid values. This is especially true for the first stack frame, where it is not possible to tell if the return address has been written to the stack already or not. Reported-by: Daan De Meyer <daan.j.demeyer@gmail.com> Reported-by: Neal Gompa <ngompa@fedoraproject.org> Closes: https://lore.kernel.org/all/CAO8sHcn3+_qrnvp0580aK7jN0Wion5F7KYeBAa4MnCY4mqABPA@mail.gmail.com/ Link: https://lore.kernel.org/all/20231030123558.10816-A-hca@linux.ibm.com Reviewed-by: Neal Gompa <ngompa@fedoraproject.org> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/include')
-rw-r--r--arch/s390/include/asm/stacktrace.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/s390/include/asm/stacktrace.h b/arch/s390/include/asm/stacktrace.h
index 78f7b729b65f..31ec4f545e03 100644
--- a/arch/s390/include/asm/stacktrace.h
+++ b/arch/s390/include/asm/stacktrace.h
@@ -6,6 +6,13 @@
#include <linux/ptrace.h>
#include <asm/switch_to.h>
+struct stack_frame_user {
+ unsigned long back_chain;
+ unsigned long empty1[5];
+ unsigned long gprs[10];
+ unsigned long empty2[4];
+};
+
enum stack_type {
STACK_TYPE_UNKNOWN,
STACK_TYPE_TASK,