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Diffstat (limited to 'gitlab/issues/target_sparc/host_missing/accel_TCG/2385.toml')
| -rw-r--r-- | gitlab/issues/target_sparc/host_missing/accel_TCG/2385.toml | 119 |
1 files changed, 0 insertions, 119 deletions
diff --git a/gitlab/issues/target_sparc/host_missing/accel_TCG/2385.toml b/gitlab/issues/target_sparc/host_missing/accel_TCG/2385.toml deleted file mode 100644 index b9fb2bed..00000000 --- a/gitlab/issues/target_sparc/host_missing/accel_TCG/2385.toml +++ /dev/null @@ -1,119 +0,0 @@ -id = 2385 -title = "sparc: SIGILL stepping over `std` in gdb" -state = "opened" -created_at = "2024-06-07T21:44:15.092Z" -closed_at = "n/a" -labels = ["accel: TCG", "target: sparc"] -url = "https://gitlab.com/qemu-project/qemu/-/issues/2385" -host-os = "Ubuntu Linux 22.04 (6.5.0-35-generic)" -host-arch = "x86_64" -qemu-version = "8.2.94 (v9.0.0-rc4)" -guest-os = "Solaris 9" -guest-arch = "sparc" -description = """Certain cases of single-stepping thru the `std` store double-word instruction causes SIGILL fatal trap, while normal execution of the program is fine. Unfortunately I do not have access to real SPARC hardware so I cannot attest whether this is an emulation issue or not. - -My previous bugfix #2281 fixed any single-stepping in a debugger from panicking the kernel, associated with the `lda` on ASI_USERTXT in the `default_fuword32` function. I suspect further bugs like this could be related somehow. Perhaps a different instruction is used for the 64-bit access that needs a similar fix. - -This problem was experienced while testing some shell-spawning assembly: -``` --bash-4.3$ cat test.s -.section ".text" -.global main -main: - sethi %hi(0x2f626800), %l6 - or %l6, 0x16e, %l6 ! 0x2f62696e - sethi %hi(0x2f6b7000), %l7 - or %l7, 0x368, %l7 ! 0x2f6b7368 - and %sp, %sp, %o0 - add %sp, 0xc, %o1 - xor %o2, %o2, %o2 - add %sp, 0x14, %sp - std %l6, [ %sp + -20 ] - clr [ %sp + -12 ] - st %sp, [ %sp + -8 ] - clr [ %sp + -4 ] - mov 0x3b, %g1 - ta 8 - xor %o7, %o7, %o0 - mov 1, %g1 - ta 8 -``` - -``` --bash-4.3$ gcc test.s -o test --bash-4.3$ ./test -$ echo HELLO -HELLO -$ exit -``` - -As you can see the program works when ran directly from the shell, but when single-stepping in gdb, a SIGILL (illegal instruction) trap occurs -``` --bash-4.3$ gdb test -GNU gdb (GDB) 7.4.1 -[...] -(gdb) disas main -Dump of assembler code for function main: - 0x0001061c <+0>: sethi %hi(0x2f626800), %l6 - 0x00010620 <+4>: or %l6, 0x16e, %l6 ! 0x2f62696e - 0x00010624 <+8>: sethi %hi(0x2f6b7000), %l7 - 0x00010628 <+12>: or %l7, 0x368, %l7 ! 0x2f6b7368 - 0x0001062c <+16>: and %sp, %sp, %o0 - 0x00010630 <+20>: add %sp, 0xc, %o1 - 0x00010634 <+24>: xor %o2, %o2, %o2 - 0x00010638 <+28>: add %sp, 0x14, %sp - 0x0001063c <+32>: std %l6, [ %sp + -20 ] - 0x00010640 <+36>: clr [ %sp + -12 ] - 0x00010644 <+40>: st %sp, [ %sp + -8 ] - 0x00010648 <+44>: clr [ %sp + -4 ] - 0x0001064c <+48>: mov 0x3b, %g1 - 0x00010650 <+52>: ta 8 - 0x00010654 <+56>: xor %o7, %o7, %o0 - 0x00010658 <+60>: mov 1, %g1 - 0x0001065c <+64>: ta 8 -End of assembler dump. -(gdb) b main -Breakpoint 1 at 0x1061c -(gdb) r -Starting program: /export/home/bazz/iob/test - -Breakpoint 1, 0x0001061c in main () -(gdb) si -0x00010620 in main () -(gdb) -0x00010624 in main () -[...] -Program received signal SIGILL, Illegal instruction. -0x0001063c in main () -``` - -However, if I continue execution _over_ the `std` instruction, the SIGILL does not occur. it will get to the usual SIGTRAP after execve, -but then complains about memory accesses that I've never seen before. -``` -(gdb) r -Starting program: /export/home/bazz/iob/test - -Breakpoint 1, 0x0001061c in main () -(gdb) c -Continuing. - -Program received signal SIGTRAP, Trace/breakpoint trap. -0xef783af4 in _rt_boot () from /usr/lib/ld.so.1 -(gdb) c -Continuing. -Cannot access memory at address 0x2800007 -Cannot access memory at address 0x2800003 -(gdb) c -Continuing. -Cannot access memory at address 0x2800007 -Cannot access memory at address 0x2800003 -(gdb) c -Continuing. -$ -``` - -It does eventually get a shell though. - -On mdb, instead of single-stepping into a SIGILL, everything goes unresponsive after stepping the `std` instruction. Then I have to kill mdb.""" -reproduce = "n/a" -additional = "n/a" |