[for-linus][PATCH 8/8] samples: ftrace: Replace bti assembly with hint for older compiler

From: Steven Rostedt
Date: Mon Aug 21 2023 - 22:39:00 EST


From: "GONG, Ruiqi" <gongruiqi1@xxxxxxxxxx>

When cross-building the arm64 kernel with allmodconfig using GCC 9.4,
the following error occurs on multiple files under samples/ftrace/:

/tmp/ccPC1ODs.s: Assembler messages:
/tmp/ccPC1ODs.s:8: Error: selected processor does not support `bti c'

Fix this issue by replacing `bti c` with `hint 34`, which is compatible
for the older compiler.

Link: https://lore.kernel.org/linux-trace-kernel/20230820111509.1470826-1-gongruiqi@xxxxxxxxxxxxxxx

Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Florent Revest <revest@xxxxxxxxxxxx>
Fixes: 8c3526fb86060cb5 ("arm64: ftrace: Add direct call trampoline samples support")
Acked-by: Mark Rutland <mark.rutland@xxxxxxx>
Signed-off-by: GONG, Ruiqi <gongruiqi1@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
samples/ftrace/ftrace-direct-modify.c | 4 ++--
samples/ftrace/ftrace-direct-multi-modify.c | 4 ++--
samples/ftrace/ftrace-direct-multi.c | 2 +-
samples/ftrace/ftrace-direct-too.c | 2 +-
samples/ftrace/ftrace-direct.c | 2 +-
5 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
index e5ed08098ff3..e2a6a69352df 100644
--- a/samples/ftrace/ftrace-direct-modify.c
+++ b/samples/ftrace/ftrace-direct-modify.c
@@ -105,7 +105,7 @@ asm (
" .type my_tramp1, @function\n"
" .globl my_tramp1\n"
" my_tramp1:"
-" bti c\n"
+" hint 34\n" // bti c
" sub sp, sp, #16\n"
" stp x9, x30, [sp]\n"
" bl my_direct_func1\n"
@@ -117,7 +117,7 @@ asm (
" .type my_tramp2, @function\n"
" .globl my_tramp2\n"
" my_tramp2:"
-" bti c\n"
+" hint 34\n" // bti c
" sub sp, sp, #16\n"
" stp x9, x30, [sp]\n"
" bl my_direct_func2\n"
diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c
index 292cff2b3f5d..2e349834d63c 100644
--- a/samples/ftrace/ftrace-direct-multi-modify.c
+++ b/samples/ftrace/ftrace-direct-multi-modify.c
@@ -112,7 +112,7 @@ asm (
" .type my_tramp1, @function\n"
" .globl my_tramp1\n"
" my_tramp1:"
-" bti c\n"
+" hint 34\n" // bti c
" sub sp, sp, #32\n"
" stp x9, x30, [sp]\n"
" str x0, [sp, #16]\n"
@@ -127,7 +127,7 @@ asm (
" .type my_tramp2, @function\n"
" .globl my_tramp2\n"
" my_tramp2:"
-" bti c\n"
+" hint 34\n" // bti c
" sub sp, sp, #32\n"
" stp x9, x30, [sp]\n"
" str x0, [sp, #16]\n"
diff --git a/samples/ftrace/ftrace-direct-multi.c b/samples/ftrace/ftrace-direct-multi.c
index b4391e08c913..9243dbfe4d0c 100644
--- a/samples/ftrace/ftrace-direct-multi.c
+++ b/samples/ftrace/ftrace-direct-multi.c
@@ -75,7 +75,7 @@ asm (
" .type my_tramp, @function\n"
" .globl my_tramp\n"
" my_tramp:"
-" bti c\n"
+" hint 34\n" // bti c
" sub sp, sp, #32\n"
" stp x9, x30, [sp]\n"
" str x0, [sp, #16]\n"
diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
index e9804c5307c0..e39c3563ae4e 100644
--- a/samples/ftrace/ftrace-direct-too.c
+++ b/samples/ftrace/ftrace-direct-too.c
@@ -81,7 +81,7 @@ asm (
" .type my_tramp, @function\n"
" .globl my_tramp\n"
" my_tramp:"
-" bti c\n"
+" hint 34\n" // bti c
" sub sp, sp, #48\n"
" stp x9, x30, [sp]\n"
" stp x0, x1, [sp, #16]\n"
diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c
index 20f4a7caa810..32c477da1e9a 100644
--- a/samples/ftrace/ftrace-direct.c
+++ b/samples/ftrace/ftrace-direct.c
@@ -72,7 +72,7 @@ asm (
" .type my_tramp, @function\n"
" .globl my_tramp\n"
" my_tramp:"
-" bti c\n"
+" hint 34\n" // bti c
" sub sp, sp, #32\n"
" stp x9, x30, [sp]\n"
" str x0, [sp, #16]\n"
--
2.40.1