[v8,0/2] linux-user: add openat2 support in linux-user

Message

Michael Vogt Sept. 30, 2024, 5:07 p.m. UTC

This is v8 of the openat2 support in linux-user. Thanks for the
feedback from Laurent on v7, really appreciated.

This version addresses the feedback for v7. It's mostly details, see
the changelog below.


Looking forward to your feedback/ideas!

Thanks,
 Michael


v7 -> v8
- use "tswap64(how.flags)" in do_openat2()
- drop printing "size=" from strace.c

v6 -> v7
- use abi_ulong in guest_size
- use TARGET_ABI_FMT_lu to format guest size in qemu_log_mask()
- drop #ifdef for TARGET_NR_openat2
- fix LTP test by checking for RESOLVE_NO_{MAGIC,SYM}LINKS in
  maybe_do_fake_open()
- add support for openat2 in strace.c
- add copy_struct_from_user definition to qemu.h
- add open_how_v0 to syscall_defs.h

v5 -> v6
- do not use get_errno(fd) in do_guest_openat()
- do not put declarations in the middle of the code
- do not return early in do_openat2() when we get a faked file

v4 -> v5
- drop "*use_returned_fd" from maybe_do_fake_open() and use return value
  -2 to signal to the caller to continue
- keep "pathname" in parameter to do_guest_openat() for a cleaner diff
- fix two missing get_errno(fd)

v3 -> v4:
- fix typos in the commit message

v2 -> v3:
- fix coding style (braches)
- improve argument args/naming in do_openat2()
- merge do_openat2/do_guest_openat2
- do size checks first in do_openat2
- add "copy_struct_from_user" and use in "do_openat2()"
- drop using openat2.h and create "struct open_how_v0"
- log if open_how guest struct is bigger than our supported struct

v1 -> v2:
- do not include <sys/syscall.h>
- drop do_guest_openat2 from qemu.h and make static
- drop "safe" from do_guest_openat2
- ensure maybe_do_fake_open() is correct about when the result should
  be used or not
- Extract do_openat2() helper from do_syscall1()
- Call user_unlock* if a lock call fails
- Fix silly incorrect use of "target_open_how" when "open_how" is required
- Fix coding style comments
- Fix validation of arg4 in openat2
- Fix missing zero initialization of open_how
- Define target_open_how with abi_* types
- Warn about unimplemented size if "size" of openat2 is bigger than
  target_open_how

Michael Vogt (2):
  linux-user: add openat2 support in linux-user
  linux-user: add strace support for openat2

 linux-user/qemu.h         |  9 ++++
 linux-user/strace.c       | 40 ++++++++++++++++
 linux-user/strace.list    |  3 ++
 linux-user/syscall.c      | 99 ++++++++++++++++++++++++++++++++++++++-
 linux-user/syscall_defs.h | 18 +++++++
 meson.build               |  1 +
 6 files changed, 168 insertions(+), 2 deletions(-)