diff options
Diffstat (limited to 'gitlab/issues_text/target_missing/host_missing/accel_missing/2971')
| -rw-r--r-- | gitlab/issues_text/target_missing/host_missing/accel_missing/2971 | 44 |
1 files changed, 0 insertions, 44 deletions
diff --git a/gitlab/issues_text/target_missing/host_missing/accel_missing/2971 b/gitlab/issues_text/target_missing/host_missing/accel_missing/2971 deleted file mode 100644 index 6706be6f5..000000000 --- a/gitlab/issues_text/target_missing/host_missing/accel_missing/2971 +++ /dev/null @@ -1,44 +0,0 @@ -loongarch64 crashes caused by lenient instruction decoding of vldi and xvldi -Description of problem: -Lenient instruction decoding of `vldi` and `xvldi` leads to Qemu crashes. - -The decoding of `vldi` and `xvldi` instruction allows for instructions with illegal immediates. - -`target/loongarch/insns.decode`: - -``` -vldi 0111 00111110 00 ............. ..... @v_i13 -xvldi 0111 01111110 00 ............. ..... @v_i13 -``` - -This is considered in `target/loongarch/tcg/insn_trans/trans_vec.c.inc`: - -```C - /* - * imm bit [11:8] is mode, mode value is 0-12. - * other values are invalid. - */ -``` - -However, an assertion error is raised when this condition is violated and qemu crashes: - -``` -** -ERROR:target/loongarch/insn_trans/trans_vec.c.inc:3574:vldi_get_value: code should not be reached -Bail out! ERROR:target/loongarch/insn_trans/trans_vec.c.inc:3574:vldi_get_value: code should not be reached -``` - -On hardware (Loongson 3A5000), these instructions cause a SIGILL. -Steps to reproduce: -1. compile the `test_inv_vldi` test program for loongarch64 (see additional information) -2. run `qemu-loongarch64-static ./test_inv_vldi` -Additional information: -I will post a patch for this issue to the mailing list soon. - -`test_inv_vldi` source code: - -```C -int main(int argc, char** argv) { - asm volatile(".4byte 0x73e3a000"); -} -``` |