samples/ftrace: Adjust LoongArch register restore order in direct calls

Ensure that in the ftrace direct call logic, the CPU register state
(with ra = parent return address) is restored to the correct state after
the execution of the custom trampoline function and before returning to
the traced function. Additionally, guarantee the correctness of the jump
logic for jr t0 (traced function address).

Cc: stable@vger.kernel.org
Fixes: 9cdc3b6a299c ("LoongArch: ftrace: Add direct call support")
Reported-by: Youling Tang <tangyouling@kylinos.cn>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Chenghao Duan <duanchenghao@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
index da3a9f2..1ba1927 100644 (file)
--- a/samples/ftrace/ftrace-direct-modify.c
+++ b/samples/ftrace/ftrace-direct-modify.c
@@ -176,8 +176,8 @@ asm (
 "      st.d    $t0, $sp, 0\n"
 "      st.d    $ra, $sp, 8\n"
 "      bl      my_direct_func1\n"
-"      ld.d    $t0, $sp, 0\n"
-"      ld.d    $ra, $sp, 8\n"
+"      ld.d    $ra, $sp, 0\n"
+"      ld.d    $t0, $sp, 8\n"
 "      addi.d  $sp, $sp, 16\n"
 "      jr      $t0\n"
 "      .size           my_tramp1, .-my_tramp1\n"
@@ -189,8 +189,8 @@ asm (
 "      st.d    $t0, $sp, 0\n"
 "      st.d    $ra, $sp, 8\n"
 "      bl      my_direct_func2\n"
-"      ld.d    $t0, $sp, 0\n"
-"      ld.d    $ra, $sp, 8\n"
+"      ld.d    $ra, $sp, 0\n"
+"      ld.d    $t0, $sp, 8\n"
 "      addi.d  $sp, $sp, 16\n"
 "      jr      $t0\n"
 "      .size           my_tramp2, .-my_tramp2\n"

diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c
index 8f7986d..7a7822d 100644 (file)
--- a/samples/ftrace/ftrace-direct-multi-modify.c
+++ b/samples/ftrace/ftrace-direct-multi-modify.c
@@ -199,8 +199,8 @@ asm (
 "      move    $a0, $t0\n"
 "      bl      my_direct_func1\n"
 "      ld.d    $a0, $sp, 0\n"
-"      ld.d    $t0, $sp, 8\n"
-"      ld.d    $ra, $sp, 16\n"
+"      ld.d    $ra, $sp, 8\n"
+"      ld.d    $t0, $sp, 16\n"
 "      addi.d  $sp, $sp, 32\n"
 "      jr      $t0\n"
 "      .size           my_tramp1, .-my_tramp1\n"
@@ -215,8 +215,8 @@ asm (
 "      move    $a0, $t0\n"
 "      bl      my_direct_func2\n"
 "      ld.d    $a0, $sp, 0\n"
-"      ld.d    $t0, $sp, 8\n"
-"      ld.d    $ra, $sp, 16\n"
+"      ld.d    $ra, $sp, 8\n"
+"      ld.d    $t0, $sp, 16\n"
 "      addi.d  $sp, $sp, 32\n"
 "      jr      $t0\n"
 "      .size           my_tramp2, .-my_tramp2\n"

diff --git a/samples/ftrace/ftrace-direct-multi.c b/samples/ftrace/ftrace-direct-multi.c
index db326c8..3fe6dda 100644 (file)
--- a/samples/ftrace/ftrace-direct-multi.c
+++ b/samples/ftrace/ftrace-direct-multi.c
@@ -131,8 +131,8 @@ asm (
 "      move    $a0, $t0\n"
 "      bl      my_direct_func\n"
 "      ld.d    $a0, $sp, 0\n"
-"      ld.d    $t0, $sp, 8\n"
-"      ld.d    $ra, $sp, 16\n"
+"      ld.d    $ra, $sp, 8\n"
+"      ld.d    $t0, $sp, 16\n"
 "      addi.d  $sp, $sp, 32\n"
 "      jr      $t0\n"
 "      .size           my_tramp, .-my_tramp\n"

diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
index 3d0fa26..bf2411a 100644 (file)
--- a/samples/ftrace/ftrace-direct-too.c
+++ b/samples/ftrace/ftrace-direct-too.c
@@ -143,8 +143,8 @@ asm (
 "      ld.d    $a0, $sp, 0\n"
 "      ld.d    $a1, $sp, 8\n"
 "      ld.d    $a2, $sp, 16\n"
-"      ld.d    $t0, $sp, 24\n"
-"      ld.d    $ra, $sp, 32\n"
+"      ld.d    $ra, $sp, 24\n"
+"      ld.d    $t0, $sp, 32\n"
 "      addi.d  $sp, $sp, 48\n"
 "      jr      $t0\n"
 "      .size           my_tramp, .-my_tramp\n"

diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c
index 956834b..5368c8c 100644 (file)
--- a/samples/ftrace/ftrace-direct.c
+++ b/samples/ftrace/ftrace-direct.c
@@ -124,8 +124,8 @@ asm (
 "      st.d    $ra, $sp, 16\n"
 "      bl      my_direct_func\n"
 "      ld.d    $a0, $sp, 0\n"
-"      ld.d    $t0, $sp, 8\n"
-"      ld.d    $ra, $sp, 16\n"
+"      ld.d    $ra, $sp, 8\n"
+"      ld.d    $t0, $sp, 16\n"
 "      addi.d  $sp, $sp, 32\n"
 "      jr      $t0\n"
 "      .size           my_tramp, .-my_tramp\n"