diff options
Diffstat (limited to 'gitlab/issues/target_m68k/host_missing/accel_missing/2483.toml')
| -rw-r--r-- | gitlab/issues/target_m68k/host_missing/accel_missing/2483.toml | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/gitlab/issues/target_m68k/host_missing/accel_missing/2483.toml b/gitlab/issues/target_m68k/host_missing/accel_missing/2483.toml new file mode 100644 index 000000000..28264af96 --- /dev/null +++ b/gitlab/issues/target_m68k/host_missing/accel_missing/2483.toml @@ -0,0 +1,32 @@ +id = 2483 +title = "m68k: jsr (sp) doesn't work as expected" +state = "closed" +created_at = "2024-08-06T11:15:57.592Z" +closed_at = "2024-10-09T19:11:08.750Z" +labels = ["Closed::Fixed", "target: m68k"] +url = "https://gitlab.com/qemu-project/qemu/-/issues/2483" +host-os = "n/a" +host-arch = "n/a" +qemu-version = "n/a" +guest-os = "n/a" +guest-arch = "n/a" +description = """Consider the following code (disassembly from ghidra). This copies the current `SP` to `A1` then copies 0x68 bytes from the address pointed at by `A0` to the address pointed at by `A1` with increment. This should end up with a copy of some bytes and `SP` pointing at the first. + +``` + ff8241e6 22 4f movea.l SP,A1 + ff8241e8 70 68 moveq #0x68,D0 + LAB_ff8241ea XREF[1]: ff8241ee(j) + ff8241ea 12 d8 move.b (A0)+,(A1)+ + ff8241ec 53 80 subq.l #0x1,D0 + ff8241ee 66 fa bne.b LAB_ff8241ea + ff8241f0 4e 97 jsr (SP) +``` + +`SP` is `0x3bfc` at the `jsr` so we'd expect to jump to `0x3bfc` and put the address to return to at `0x3bf8` so the `jsr` can return I think? +What currently happens in QEMU is the return address is put at `0xb3f8` and `PC` also becomes `0x3bf8` and the return address starts being executed as code and things go off the rails. + +Forgive the screenshot but this is what it looks like with GDB connected. Dumping the memory where the `PC` is shows that the return address is actually there and we can see there is garbage before the instructions it should be executing. + +{width=289 height=759}""" +reproduce = "n/a" +additional = "n/a" |