tjh.dev / kernel
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
fork atom

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>

authored by

Chenghao Duan and committed by
Huacai Chen bb85d206 73721d86

+14 -14
+4 -4
samples/ftrace/ftrace-direct-modify.c
··· 176 176 " st.d $t0, $sp, 0\n" 177 177 " st.d $ra, $sp, 8\n" 178 178 " bl my_direct_func1\n" 179 - " ld.d $t0, $sp, 0\n" 180 - " ld.d $ra, $sp, 8\n" 179 + " ld.d $ra, $sp, 0\n" 180 + " ld.d $t0, $sp, 8\n" 181 181 " addi.d $sp, $sp, 16\n" 182 182 " jr $t0\n" 183 183 " .size my_tramp1, .-my_tramp1\n" ··· 189 189 " st.d $t0, $sp, 0\n" 190 190 " st.d $ra, $sp, 8\n" 191 191 " bl my_direct_func2\n" 192 - " ld.d $t0, $sp, 0\n" 193 - " ld.d $ra, $sp, 8\n" 192 + " ld.d $ra, $sp, 0\n" 193 + " ld.d $t0, $sp, 8\n" 194 194 " addi.d $sp, $sp, 16\n" 195 195 " jr $t0\n" 196 196 " .size my_tramp2, .-my_tramp2\n"
+4 -4
samples/ftrace/ftrace-direct-multi-modify.c
··· 199 199 " move $a0, $t0\n" 200 200 " bl my_direct_func1\n" 201 201 " ld.d $a0, $sp, 0\n" 202 - " ld.d $t0, $sp, 8\n" 203 - " ld.d $ra, $sp, 16\n" 202 + " ld.d $ra, $sp, 8\n" 203 + " ld.d $t0, $sp, 16\n" 204 204 " addi.d $sp, $sp, 32\n" 205 205 " jr $t0\n" 206 206 " .size my_tramp1, .-my_tramp1\n" ··· 215 215 " move $a0, $t0\n" 216 216 " bl my_direct_func2\n" 217 217 " ld.d $a0, $sp, 0\n" 218 - " ld.d $t0, $sp, 8\n" 219 - " ld.d $ra, $sp, 16\n" 218 + " ld.d $ra, $sp, 8\n" 219 + " ld.d $t0, $sp, 16\n" 220 220 " addi.d $sp, $sp, 32\n" 221 221 " jr $t0\n" 222 222 " .size my_tramp2, .-my_tramp2\n"
+2 -2
samples/ftrace/ftrace-direct-multi.c
··· 131 131 " move $a0, $t0\n" 132 132 " bl my_direct_func\n" 133 133 " ld.d $a0, $sp, 0\n" 134 - " ld.d $t0, $sp, 8\n" 135 - " ld.d $ra, $sp, 16\n" 134 + " ld.d $ra, $sp, 8\n" 135 + " ld.d $t0, $sp, 16\n" 136 136 " addi.d $sp, $sp, 32\n" 137 137 " jr $t0\n" 138 138 " .size my_tramp, .-my_tramp\n"
+2 -2
samples/ftrace/ftrace-direct-too.c
··· 143 143 " ld.d $a0, $sp, 0\n" 144 144 " ld.d $a1, $sp, 8\n" 145 145 " ld.d $a2, $sp, 16\n" 146 - " ld.d $t0, $sp, 24\n" 147 - " ld.d $ra, $sp, 32\n" 146 + " ld.d $ra, $sp, 24\n" 147 + " ld.d $t0, $sp, 32\n" 148 148 " addi.d $sp, $sp, 48\n" 149 149 " jr $t0\n" 150 150 " .size my_tramp, .-my_tramp\n"
+2 -2
samples/ftrace/ftrace-direct.c
··· 124 124 " st.d $ra, $sp, 16\n" 125 125 " bl my_direct_func\n" 126 126 " ld.d $a0, $sp, 0\n" 127 - " ld.d $t0, $sp, 8\n" 128 - " ld.d $ra, $sp, 16\n" 127 + " ld.d $ra, $sp, 8\n" 128 + " ld.d $t0, $sp, 16\n" 129 129 " addi.d $sp, $sp, 32\n" 130 130 " jr $t0\n" 131 131 " .size my_tramp, .-my_tramp\n"