Re: [PATCH 02/15] syscalls: fix compat_sys_io_pgetevents_time64 usage

On Thu, Jun 20, 2024, at 18:23, Arnd Bergmann wrote:
> From: Arnd Bergmann <[email protected]>
>
> Using sys_io_pgetevents() as the entry point for compat mode tasks
> works almost correctly, but misses the sign extension for the min_nr
> and nr arguments.
>
> This was addressed on parisc by switching to
> compat_sys_io_pgetevents_time64() in commit 6431e92fc827 ("parisc:
> io_pgetevents_time64() needs compat syscall in 32-bit compat mode"),
> as well as by using more sophisticated system call wrappers on x86 and
> s390. However, arm64, mips, powerpc, sparc and riscv still have the
> same bug.
>
> Changes all of them over to use compat_sys_io_pgetevents_time64()
> like parisc already does. This was clearly the intention when the
> function was originally added, but it got hooked up incorrectly in
> the tables.
>
> Cc: [email protected]
> Fixes: 48166e6ea47d ("y2038: add 64-bit time_t syscalls to all 32-bit 
> architectures")
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
>  arch/arm64/include/asm/unistd32.h         | 2 +-
>  arch/mips/kernel/syscalls/syscall_n32.tbl | 2 +-
>  arch/mips/kernel/syscalls/syscall_o32.tbl | 2 +-
>  arch/powerpc/kernel/syscalls/syscall.tbl  | 2 +-
>  arch/s390/kernel/syscalls/syscall.tbl     | 2 +-
>  arch/sparc/kernel/syscalls/syscall.tbl    | 2 +-
>  arch/x86/entry/syscalls/syscall_32.tbl    | 2 +-
>  include/uapi/asm-generic/unistd.h         | 2 +-
>  8 files changed, 8 insertions(+), 8 deletions(-)

The build bot reported a randconfig regressions with this
patch, which I've now fixed up like this:

diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index d7eee421d4bc..b696b85ac63e 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -46,8 +46,8 @@ COND_SYSCALL(io_getevents_time32);
 COND_SYSCALL(io_getevents);
 COND_SYSCALL(io_pgetevents_time32);
 COND_SYSCALL(io_pgetevents);
-COND_SYSCALL_COMPAT(io_pgetevents_time32);
 COND_SYSCALL_COMPAT(io_pgetevents);
+COND_SYSCALL_COMPAT(io_pgetevents_time64);
 COND_SYSCALL(io_uring_setup);
 COND_SYSCALL(io_uring_enter);
 COND_SYSCALL(io_uring_register);

This was already broken on parisc the same way, but the
mistake in sys_ni.c turned into a link failure for every
compat architecture after my patch.

      Arnd