Hi Al, Sorry, couldn't reply earlier. On Sat, Oct 20, 2012 at 04:34:01PM +0100, Al Viro wrote: > On Sat, Oct 20, 2012 at 09:06:57AM -0400, Chris Metcalf wrote: > > First, the compat_sys_execve() declaration provided in > > arch/tile/include/asm/compat.h isn't right, so I deleted that (you had only > > deleted the PTREGS_SYSCALL trampoline declaration, _compat_sys_execve). > > > > However, then arch/tile/kernel/compat.c failed to build, because > > <linux/compat.h> is included before <asm/unistd.h>, and <asm/unistd.h> > > provides __ARCH_WANT_SYS_EXECVE, and so we end up with no declaration at > > all for compat_sys_execve. For most platforms this is no big deal, but on > > tile we use the __SYSCALL #define to provide the actual syscall table, and > > for that to work we need a declaration in scope for each syscall at the > > time we create the table. > > > > The best solution seems likely to be to copy the other place in > > <linux/compat.h> where we need to do something configurable (that is, > > CONFIG_ARCH_WANT_OLD_COMPAT_IPC), and just convert __ARCH_WANT_SYS_EXECVE > > to be a Kconfig option. > > Frankly, I hope to get rid of the damn thing completely. By now we have > at least some variant of execve conversions for just about everything; > I certainly hope that by the beginning of the next cycle we'll have it > defined on everything. And put unconditional declarations in syscalls.h > and compat.h > > Actually, we can make the declaration in linux/compat.h unconditional > right now. The only obstacle is the situation on arm64; there the mainline > has C variant of that sucker (with struct pt_regs * in arguments) in > arch/arm64/kernel/sys_compat.c. So we could ask Linus to pull > git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64 execve > and then do the following in one patch: > introduce current_pt_regs() on tile (from your commit) > get rid of pt_regs * argument in tile compat_sys_execve(), making it > use current_pt_regs(); kill its wrapper > kill the declarations of compat_sys_execve()/_compat_sys_execve() > in tile asm/compat.h > make declaration in linux/compat.h unconditional > Note that this does *not* depend on kernel_thread/kernel_execve patch - > kernel_execve() is never going to hit compat_sys_execve(), since it's > only called from kernel threads and those are not going to be 32bit. > After that we can do kernel_thread/kernel_execve commit and > sys_execve() conversion with nothing outside of arch/tile touched. > > Comments? If Catalin feels that arm64 series needs more testing, we could > reorder it a bit - all we really need there is getting rid of pt_regs argument > in compat_sys_execve() and just as on tile, that isn't tied into kernel_execve > and kernel_thread issues. I don't mind merging it earlier (if Linus is ok to take it after the merging window). It works fine in my tests. -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
