target/arm: Fix vector operation segfault

Commit 89e68b575 "target/arm: Use vector operations for saturation"
causes this abort() when booting QEMU ARM with a Cortex-A15:

0 0x00007ffff4c2382f in raise () at /usr/lib/libc.so.6
1 0x00007ffff4c0e672 in abort () at /usr/lib/libc.so.6
2 0x00005555559c1839 in disas_neon_data_insn (insn=<optimized out>, s=<optimized out>) at ./target/arm/translate.c:6673
3 0x00005555559c1839 in disas_neon_data_insn (s=<optimized out>, insn=<optimized out>) at ./target/arm/translate.c:6386
4 0x00005555559cd8a4 in disas_arm_insn (insn=4081107068, s=0x7fffe59a9510) at ./target/arm/translate.c:9289
5 0x00005555559cd8a4 in arm_tr_translate_insn (dcbase=0x7fffe59a9510, cpu=<optimized out>) at ./target/arm/translate.c:13612
6 0x00005555558d1d39 in translator_loop (ops=0x5555561cc580 <arm_translator_ops>, db=0x7fffe59a9510, cpu=0x55555686a2f0, tb=<optimized out>, max_insns=<optimized out>) at ./accel/tcg/translator.c:96
7 0x00005555559d10d4 in gen_intermediate_code (cpu=cpu@entry=0x55555686a2f0, tb=tb@entry=0x7fffd7840080 <code_gen_buffer+126091347>, max_insns=max_insns@entry=512) at ./target/arm/translate.c:13901
8 0x00005555558d06b9 in tb_gen_code (cpu=cpu@entry=0x55555686a2f0, pc=3067096216, cs_base=0, flags=192, cflags=-16252928, cflags@entry=524288) at ./accel/tcg/translate-all.c:1736
9 0x00005555558ce467 in tb_find (cf_mask=524288, tb_exit=1, last_tb=0x7fffd783e640 <code_gen_buffer+126084627>, cpu=0x1) at ./accel/tcg/cpu-exec.c:407
10 0x00005555558ce467 in cpu_exec (cpu=cpu@entry=0x55555686a2f0) at ./accel/tcg/cpu-exec.c:728
11 0x000055555588b0cf in tcg_cpu_exec (cpu=0x55555686a2f0) at ./cpus.c:1431
12 0x000055555588d223 in qemu_tcg_cpu_thread_fn (arg=0x55555686a2f0) at ./cpus.c:1735
13 0x000055555588d223 in qemu_tcg_cpu_thread_fn (arg=arg@entry=0x55555686a2f0) at ./cpus.c:1709
14 0x0000555555d2629a in qemu_thread_start (args=<optimized out>) at ./util/qemu-thread-posix.c:502
15 0x00007ffff4db8a92 in start_thread () at /usr/lib/libpthread.

This patch ensures that we don't hit the abort() in the second switch
case in disas_neon_data_insn() as we will return from the first case.

Backports commit 2f143d3ad1c05e91cf2cdf5de06d59a80a95e6c8 from qemu
This commit is contained in:
Alistair Francis 2019-05-24 18:02:20 -04:00 committed by Lioncash
parent 9287750362
commit f8f3e50372
No known key found for this signature in database
GPG key ID: 4E3C3CC1031BA9C7

View file

@ -6753,13 +6753,13 @@ static int disas_neon_data_insn(DisasContext *s, uint32_t insn)
tcg_gen_gvec_4(tcg_ctx, rd_ofs, offsetof(CPUARMState, vfp.qc),
rn_ofs, rm_ofs, vec_size, vec_size,
(u ? uqadd_op : sqadd_op) + size);
break;
return 0;
case NEON_3R_VQSUB:
tcg_gen_gvec_4(tcg_ctx, rd_ofs, offsetof(CPUARMState, vfp.qc),
rn_ofs, rm_ofs, vec_size, vec_size,
(u ? uqsub_op : sqsub_op) + size);
break;
return 0;
case NEON_3R_VMUL: /* VMUL */
if (u) {