On Thu, Nov 26, 2020 at 7:52 AM Jan Kara jack@suse.cz wrote:
Commit converting syscalls taking 64-bit arguments to new scheme of compat handlers omitted converting fanotify_mark(2) which then broke the syscall for 32-bit x86 builds. Add missed conversion. It is somewhat cumbersome since we need to keep the original compat handler for all the other 32-bit archs.
This is stupendously ugly. I'm not really sure how this is supposed to work on any 32-bit arch. I'm also not sure whether we should expect the SYSCALL_DEFINE macros to figure this out by themselves.
At the very least, the native arm 32 and arm64 compat cases should get tested.
Al and Christoph, you're probably a lot more familiar than I am with the nasty details of syscall ABI with 64-bit arguments.
CC: Brian Gerst brgerst@gmail.com Suggested-by: Borislav Petkov bp@suse.de Reported-by: Paweł Jasiak pawel@jasiak.xyz Reported-and-tested-by: Naresh Kamboju naresh.kamboju@linaro.org Fixes: 121b32a58a3a ("x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments") CC: stable@vger.kernel.org Signed-off-by: Jan Kara jack@suse.cz
arch/x86/entry/syscalls/syscall_32.tbl | 2 +- fs/notify/fanotify/fanotify_user.c | 7 ++++++- 2 files changed, 7 insertions(+), 2 deletions(-)
I plan to queue this fix into my tree next week. I'd be happy if someone with x86 ABI knowledge checks whether I've got the patch right (especially various config variants) because it was mostly a guesswork of me & Boris ;). Thanks!
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index 0d0667a9fbd7..b2ec6ff88307 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -350,7 +350,7 @@ 336 i386 perf_event_open sys_perf_event_open 337 i386 recvmmsg sys_recvmmsg_time32 compat_sys_recvmmsg_time32 338 i386 fanotify_init sys_fanotify_init -339 i386 fanotify_mark sys_fanotify_mark compat_sys_fanotify_mark +339 i386 fanotify_mark sys_ia32_fanotify_mark 340 i386 prlimit64 sys_prlimit64 341 i386 name_to_handle_at sys_name_to_handle_at 342 i386 open_by_handle_at sys_open_by_handle_at compat_sys_open_by_handle_at diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 3e01d8f2ab90..ba38f0fec4d0 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -1292,8 +1292,13 @@ SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags, return do_fanotify_mark(fanotify_fd, flags, mask, dfd, pathname); }
-#ifdef CONFIG_COMPAT +#if defined(CONFIG_COMPAT) || defined(CONFIG_X86_32) || \
- defined(CONFIG_IA32_EMULATION)
+#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION) +SYSCALL_DEFINE6(ia32_fanotify_mark, +#elif CONFIG_COMPAT COMPAT_SYSCALL_DEFINE6(fanotify_mark, +#endif int, fanotify_fd, unsigned int, flags, __u32, mask0, __u32, mask1, int, dfd, const char __user *, pathname) -- 2.16.4