Extend the record alignment to the legacy getdents path. The kernel rounds
both getdents and getdents64 records up to the alignment of their leading
d_ino (ALIGN(reclen, sizeof(long))); without it a strict-alignment guest
(MIPS) faults walking the buffer, e.g. older glibc busybox 'ls' (which uses
the legacy getdents syscall) crashes on directory listings.
Legacy linux_dirent stores d_type in the record's last byte (offset
d_reclen-1), so the alignment padding goes between d_name and d_type to keep
d_type there -- padding without relocating d_type is what got the earlier
blanket attempt (PR #1419) reverted. getdents64 (d_type before d_name) is
unchanged.
Add test_linux_getdents_alignment: walks legacy getdents records on a
big-endian MIPS guest and asserts each is aligned, tiles the buffer, and
keeps d_type (DT_DIR for '.'/'..'). Runs on stock unicorn.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Modern glibc (recent toolchains) issues clone3 from pthread_create rather
than clone, so thread creation fails on any guest built against it: Qiling
does not return -ENOSYS for unimplemented syscalls (it logs a warning and
leaves the return register untouched), so glibc's clone3->clone fallback
never fires.
Add ql_syscall_clone3, which unpacks struct clone_args and delegates to the
existing clone() handler. Translations: child_stack = stack + stack_size
(clone3 passes the stack base plus a size; legacy clone wants the highest
address), exit_signal folded into the flags' CSIGNAL byte, and an x8664
pre-swap that cancels ql_syscall_clone's arch-specific newtls<->child_tidptr
swap.
Add a self-contained regression test (test_clone3_translates_to_clone) that
drives ql_syscall_clone3 directly and asserts the translation for both the
generic path and the x8664 swap. Runs on stock unicorn; no clone3 binary
needed.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Calls ql_syscall_getdents64 on a directory and walks the returned
linux_dirent64 records, asserting every record (and thus its leading u64
d_ino) starts on an 8-byte boundary. Before the fix d_reclen was not
rounded up, so records were misaligned and a strict-alignment guest (e.g.
MIPS) faulted with an unaligned load. Self-contained; runs on stock unicorn.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
getdents64 wrote linux_dirent64 records with d_reclen = header + name,
without rounding up to the alignment of the leading u64 d_ino. The next
record's d_ino then lands unaligned, and a strict-alignment guest (e.g.
MIPS/MIPS64) faults with UC_ERR_READ_UNALIGNED when walking the buffer.
x86 tolerates the unaligned load, which is why this was never caught.
Round d_reclen up to the d_ino alignment, matching the kernel. The rounding
is scoped to the getdents64 (is_64) branch only: getdents64 places d_type
before d_name so the trailing pad bytes are inert, whereas the legacy
getdents layout stores d_type at offset d_reclen-1 and would break if padded
the same way -- that is what got the earlier blanket fix (PR #1419) reverted.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
