ftrace/samples: add s390 support for ftrace direct multi sample

Add s390 architecture support for the ftrace direct multi sample.
See commit 5fae941b9a6f ("ftrace/samples: Add multi direct interface
test module") for further details.

Link: https://lore.kernel.org/r/20211115195614.3173346-3-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 35f99b8f236e4a56e49e1de3fce02b7fac616672..2a5bb4f29cfede5a627b61795e6d6b133c979ccd 100644 (file)
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -194,6 +194,7 @@ config S390
        select HAVE_RELIABLE_STACKTRACE
        select HAVE_RSEQ
        select HAVE_SAMPLE_FTRACE_DIRECT
+       select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
        select HAVE_SOFTIRQ_ON_OWN_STACK
        select HAVE_SYSCALL_TRACEPOINTS
        select HAVE_VIRT_CPU_ACCOUNTING

diff --git a/samples/ftrace/ftrace-direct-multi.c b/samples/ftrace/ftrace-direct-multi.c
index b6d7806b400e4966212146fe45f844c8be8ba8d9..2fafc9afcbf0fcf31df7eaebd8fd0c19fa44fd28 100644 (file)
--- a/samples/ftrace/ftrace-direct-multi.c
+++ b/samples/ftrace/ftrace-direct-multi.c
@@ -4,6 +4,7 @@
 #include <linux/mm.h> /* for handle_mm_fault() */
 #include <linux/ftrace.h>
 #include <linux/sched/stat.h>
+#include <asm/asm-offsets.h>
 
 extern void my_direct_func(unsigned long ip);
 
@@ -14,6 +15,8 @@ void my_direct_func(unsigned long ip)
 
 extern void my_tramp(void *);
 
+#ifdef CONFIG_X86_64
+
 asm (
 "      .pushsection    .text, \"ax\", @progbits\n"
 "      .type           my_tramp, @function\n"
@@ -31,6 +34,33 @@ asm (
 "      .popsection\n"
 );
 
+#endif /* CONFIG_X86_64 */
+
+#ifdef CONFIG_S390
+
+asm (
+"      .pushsection    .text, \"ax\", @progbits\n"
+"      .type           my_tramp, @function\n"
+"      .globl          my_tramp\n"
+"   my_tramp:"
+"      lgr             %r1,%r15\n"
+"      stmg            %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+"      stg             %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+"      aghi            %r15,"__stringify(-STACK_FRAME_OVERHEAD)"\n"
+"      stg             %r1,"__stringify(__SF_BACKCHAIN)"(%r15)\n"
+"      lgr             %r2,%r0\n"
+"      brasl           %r14,my_direct_func\n"
+"      aghi            %r15,"__stringify(STACK_FRAME_OVERHEAD)"\n"
+"      lmg             %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
+"      lg              %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
+"      lgr             %r1,%r0\n"
+"      br              %r1\n"
+"      .size           my_tramp, .-my_tramp\n"
+"      .popsection\n"
+);
+
+#endif /* CONFIG_S390 */
+
 static struct ftrace_ops direct;
 
 static int __init ftrace_direct_multi_init(void)