Re: [RFC PATCH 3/6] fs: provide generic compat_sys_p{read, write}64() implementations
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: 2018-03-18 17:40:26
Also in:
linux-arch, linux-mips, linux-s390, lkml, sparclinux
Honestly, I think the patches like this are disgusting: On Sun, Mar 18, 2018 at 9:10 AM, Dominik Brodowski [off-list ref] wrote:
quoted hunk ↗ jump to hunk
+#ifdef __ARCH_WANT_COMPAT_SYS_PREADWRITE64 +#if defined(__ARCH_WANT_COMPAT_SYS_WITH_PADDING) && \ + defined(__ARCH_WANT_LE_COMPAT_SYS) +COMPAT_SYSCALL_DEFINE6(pread64, unsigned int, fd, char __user *, ubuf, + u32, count, u32, padding, u32, poslo, u32, poshi) +#elif defined(__ARCH_WANT_COMPAT_SYS_WITH_PADDING) && \ + !defined(__ARCH_WANT_LE_COMPAT_SYS) +COMPAT_SYSCALL_DEFINE6(pread64, unsigned int, fd, char __user *, ubuf, + u32, count, u32, padding, u32, poshi, u32, poslo) +#elif !defined(__ARCH_WANT_COMPAT_SYS_WITH_PADDING) && \ + defined(__ARCH_WANT_LE_COMPAT_SYS) +COMPAT_SYSCALL_DEFINE5(pread64, unsigned int, fd, char __user *, ubuf, + u32, count, u32, poslo, u32, poshi) +#else /* no padding, big endian */ +COMPAT_SYSCALL_DEFINE5(pread64, unsigned int, fd, char __user *, ubuf, + u32, count, u32, poshi, u32, poslo) +#endif +{ +#ifdef CONFIG_S390 + if ((compat_ssize_t) count < 0) + return -EINVAL; +#endif /* CONFIG_S390 */
and we should just keep code like this entirely architecture-dependent.
It doesn't save all that many lines:
19 files changed, 97 insertions(+), 106 deletions(-)
and the lines it adds are an unreadable mess compared to the lines it removes.
So please keep the high/low/padding stuff in the arch wrapper, and
just make them use "do_pwrite64()" and friends instead (or
"kern_pwrite64()", or whatever we ended up using as the kernel naming
for in-kernel system call wrappers).
Linus