From: Arnd Bergmann arnd@arndb.de
[ Upstream commit 403f17a330732a666ae793f3b15bc75bb5540524 ]
The sys_fanotify_mark() syscall on parisc uses the reverse word order for the two halves of the 64-bit argument compared to all syscalls on all 32-bit architectures. As far as I can tell, the problem is that the function arguments on parisc are sorted backwards (26, 25, 24, 23, ...) compared to everyone else, so the calling conventions of using an even/odd register pair in native word order result in the lower word coming first in function arguments, matching the expected behavior on little-endian architectures. The system call conventions however ended up matching what the other 32-bit architectures do.
A glibc cleanup in 2020 changed the userspace behavior in a way that handles all architectures consistently, but this inadvertently broke parisc32 by changing to the same method as everyone else.
The change made it into glibc-2.35 and subsequently into debian 12 (bookworm), which is the latest stable release. This means we need to choose between reverting the glibc change or changing the kernel to match it again, but either hange will leave some systems broken.
Pick the option that is more likely to help current and future users and change the kernel to match current glibc. This also means the behavior is now consistent across architectures, but it breaks running new kernels with old glibc builds before 2.35.
Link: https://sourceware.org/git/?p=glibc.git%3Ba=commitdiff%3Bh=d150181d73d9 Link: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/a... Cc: Adhemerval Zanella adhemerval.zanella@linaro.org Tested-by: Helge Deller deller@gmx.de Acked-by: Helge Deller deller@gmx.de Signed-off-by: Arnd Bergmann arnd@arndb.de --- I found this through code inspection, please double-check to make sure I got the bug and the fix right.
The alternative is to fix this by reverting glibc back to the unusual behavior.
Signed-off-by: Sasha Levin sashal@kernel.org --- arch/parisc/Kconfig | 1 + arch/parisc/kernel/sys_parisc32.c | 9 --------- arch/parisc/kernel/syscalls/syscall.tbl | 2 +- 3 files changed, 2 insertions(+), 10 deletions(-)
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index daafeb20f9937..dc9b902de8ea9 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -16,6 +16,7 @@ config PARISC select ARCH_HAS_UBSAN select ARCH_HAS_PTE_SPECIAL select ARCH_NO_SG_CHAIN + select ARCH_SPLIT_ARG64 if !64BIT select ARCH_SUPPORTS_HUGETLBFS if PA20 select ARCH_SUPPORTS_MEMORY_FAILURE select ARCH_STACKWALK diff --git a/arch/parisc/kernel/sys_parisc32.c b/arch/parisc/kernel/sys_parisc32.c index 2a12a547b447b..826c8e51b5853 100644 --- a/arch/parisc/kernel/sys_parisc32.c +++ b/arch/parisc/kernel/sys_parisc32.c @@ -23,12 +23,3 @@ asmlinkage long sys32_unimplemented(int r26, int r25, int r24, int r23, current->comm, current->pid, r20); return -ENOSYS; } - -asmlinkage long sys32_fanotify_mark(compat_int_t fanotify_fd, compat_uint_t flags, - compat_uint_t mask0, compat_uint_t mask1, compat_int_t dfd, - const char __user * pathname) -{ - return sys_fanotify_mark(fanotify_fd, flags, - ((__u64)mask1 << 32) | mask0, - dfd, pathname); -} diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl index b236a84c4e127..5439ff05bdb2d 100644 --- a/arch/parisc/kernel/syscalls/syscall.tbl +++ b/arch/parisc/kernel/syscalls/syscall.tbl @@ -364,7 +364,7 @@ 320 common accept4 sys_accept4 321 common prlimit64 sys_prlimit64 322 common fanotify_init sys_fanotify_init -323 common fanotify_mark sys_fanotify_mark sys32_fanotify_mark +323 common fanotify_mark sys_fanotify_mark compat_sys_fanotify_mark 324 32 clock_adjtime sys_clock_adjtime32 324 64 clock_adjtime sys_clock_adjtime 325 common name_to_handle_at sys_name_to_handle_at