lwn.git/arch/arm/kernel/sys_oabi-compat.c, branch header-removal

ARM: 9110/1: oabi-compat: fix oabi epoll sparse warning

2021-08-20T10:39:27+00:00

As my patches change the oabi epoll definition, I received a report from the kernel test robot about a pre-existing issue with a mismatched __poll_t type. The OABI code was correct when it was initially added in linux-2.16, but a later (also correct) change to the generic __poll_t triggered a type mismatch warning from sparse. As __poll_t is always 32-bit bits wide and otherwise compatible, using this instead of __u32 in the oabi_epoll_event definition is a valid workaround. Reported-by: kernel test robot Fixes: 8ced390c2b18 ("define __poll_t, annotate constants") Fixes: ee219b946e4b ("uapi: turn __poll_t sparse checks on by default") Fixes: 687ad0191488 ("[ARM] 3109/1: old ABI compat: syscall wrappers for ABI impedance matching") Acked-by: Christoph Hellwig Signed-off-by: Arnd Bergmann Signed-off-by: Russell King (Oracle)

ARM: 9111/1: oabi-compat: rework fcntl64() emulation

2021-08-20T10:39:27+00:00

This is one of the last users of get_fs(), and this is fairly easy to change, since the infrastructure for it is already there. The replacement here is essentially a copy of the existing fcntl64() syscall entry function. Acked-by: Christoph Hellwig Signed-off-by: Arnd Bergmann Signed-off-by: Russell King (Oracle)

ARM: 9114/1: oabi-compat: rework sys_semtimedop emulation

2021-08-20T10:39:26+00:00

sys_oabi_semtimedop() is one of the last users of set_fs() on Arm. To remove this one, expose the internal code of the actual implementation that operates on a kernel pointer and call it directly after copying. There should be no measurable impact on the normal execution of this function, and it makes the overly long function a little shorter, which may help readability. While reworking the oabi version, make it behave a little more like the native one, using kvmalloc_array() and restructure the code flow in a similar way. The naming of __do_semtimedop() is not very good, I hope someone can come up with a better name. One regression was spotted by kernel test robot and fixed before the first mailing list submission. Acked-by: Christoph Hellwig Signed-off-by: Arnd Bergmann Signed-off-by: Russell King (Oracle)

ARM: 9108/1: oabi-compat: rework epoll_wait/epoll_pwait emulation

2021-08-20T10:39:26+00:00

The epoll_wait() system call wrapper is one of the remaining users of the set_fs() infrasturcture for Arm. Changing it to not require set_fs() is rather complex unfortunately. The approach I'm taking here is to allow architectures to override the code that copies the output to user space, and let the oabi-compat implementation check whether it is getting called from an EABI or OABI system call based on the thread_info->syscall value. The in_oabi_syscall() check here mirrors the in_compat_syscall() and in_x32_syscall() helpers for 32-bit compat implementations on other architectures. Overall, the amount of code goes down, at least with the newly added sys_oabi_epoll_pwait() helper getting removed again. The downside is added complexity in the source code for the native implementation. There should be no difference in runtime performance except for Arm kernels with CONFIG_OABI_COMPAT enabled that now have to go through an external function call to check which of the two variants to use. Acked-by: Christoph Hellwig Signed-off-by: Arnd Bergmann Signed-off-by: Russell King (Oracle)

ARM: 9109/1: oabi-compat: add epoll_pwait handler

2021-08-20T10:39:26+00:00

The epoll_wait() syscall has a special version for OABI compat mode to convert the arguments to the EABI structure layout of the kernel. However, the later epoll_pwait() syscall was added in arch/arm in linux-2.6.32 without this conversion. Use the same kind of handler for both. Fixes: 369842658a36 ("ARM: 5677/1: ARM support for TIF_RESTORE_SIGMASK/pselect6/ppoll/epoll_pwait") Cc: stable@vger.kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Arnd Bergmann Signed-off-by: Russell King (Oracle)

ARM: 9065/1: OABI compat: fix build when EPOLL is not enabled

2021-02-22T13:07:13+00:00

When CONFIG_EPOLL is not set/enabled, sys_oabi-compat.c has build errors. Fix these by surrounding them with ifdef CONFIG_EPOLL/endif and providing stubs for the "EPOLL is not set" case. ../arch/arm/kernel/sys_oabi-compat.c: In function 'sys_oabi_epoll_ctl': ../arch/arm/kernel/sys_oabi-compat.c:257:6: error: implicit declaration of function 'ep_op_has_event' [-Werror=implicit-function-declaration] 257 | if (ep_op_has_event(op) && | ^~~~~~~~~~~~~~~ ../arch/arm/kernel/sys_oabi-compat.c:264:9: error: implicit declaration of function 'do_epoll_ctl'; did you mean 'sys_epoll_ctl'? [-Werror=implicit-function-declaration] 264 | return do_epoll_ctl(epfd, op, fd, &kernel, false); | ^~~~~~~~~~~~ Fixes: c281634c8652 ("ARM: compat: remove KERNEL_DS usage in sys_oabi_epoll_ctl()") Signed-off-by: Randy Dunlap Reported-by: kernel test robot # from an lkp .config file Cc: linux-arm-kernel@lists.infradead.org Cc: Nicolas Pitre Cc: Alexander Viro Cc: patches@armlinux.org.uk Acked-by: Nicolas Pitre Signed-off-by: Russell King

ARM: compat: remove KERNEL_DS usage in sys_oabi_epoll_ctl()

2020-04-21T16:49:30+00:00

We no longer need to switch to KERNEL_DS mode in sys_oabi_epoll_ctl() as we can use do_epoll_ctl() to avoid the additional copy. Reviewed-by: Christoph Hellwig Signed-off-by: Russell King

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55+00:00

Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Enrico Weigelt Reviewed-by: Kate Stewart Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman

y2038: use time32 syscall names on 32-bit

2019-02-06T23:13:28+00:00

This is the big flip, where all 32-bit architectures set COMPAT_32BIT_TIME and use the _time32 system calls from the former compat layer instead of the system calls that take __kernel_timespec and similar arguments. The temporary redirects for __kernel_timespec, __kernel_itimerspec and __kernel_timex can get removed with this. It would be easy to split this commit by architecture, but with the new generated system call tables, it's easy enough to do it all at once, which makes it a little easier to check that the changes are the same in each table. Acked-by: Geert Uytterhoeven Signed-off-by: Arnd Bergmann

Remove 'type' argument from access_ok() function

2019-01-04T02:57:57+00:00

Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds