kernel/linux.git/arch/s390/include/asm/syscall_wrapper.h, branch v6.19.12

s390: Remove compat support

2025-11-17T10:10:38+00:00

There shouldn't be any 31 bit code around anymore that matters. Remove the compat layer support required to run 31 bit code. Reason for removal is code simplification and reduced test effort. Note that this comes without any deprecation warnings added to config options, or kernel messages, since most likely those would be ignored anyway. If it turns out there is still a reason to keep the compat layer this can be reverted at any time in the future. Reviewed-by: Arnd Bergmann Signed-off-by: Heiko Carstens

s390/syscalls: Add pt_regs parameter to SYSCALL_DEFINE0() syscall wrapper

2025-11-17T10:10:38+00:00

All system call wrappers should match the sys_call_ptr_t type. This is not the case for system calls without parameters. Add the missing pt_regs parameter there too. Note: this is currently not a problem, since the parameter is unused. However it prevents to create a correctly typed system call table in C. With the current assembler implementation this works because of missing type checking. Reviewed-by: Arnd Bergmann Signed-off-by: Heiko Carstens

posix-timers: Get rid of [COMPAT_]SYS_NI() uses

2023-12-21T05:30:27+00:00

Only the posix timer system calls use this (when the posix timer support is disabled, which does not actually happen in any normal case), because they had debug code to print out a warning about missing system calls. Get rid of that special case, and just use the standard COND_SYSCALL interface that creates weak system call stubs that return -ENOSYS for when the system call does not exist. This fixes a kCFI issue with the SYS_NI() hackery: CFI failure at int80_emulation+0x67/0xb0 (target: sys_ni_posix_timers+0x0/0x70; expected type: 0xb02b34d9) WARNING: CPU: 0 PID: 48 at int80_emulation+0x67/0xb0 Reported-by: kernel test robot Reviewed-by: Sami Tolvanen Tested-by: Sami Tolvanen Cc: Thomas Gleixner Cc: Dave Hansen Cc: Borislav Petkov Signed-off-by: Linus Torvalds

s390/syscalls: get rid of system call alias functions

2023-01-25T19:51:11+00:00

bpftrace and friends only consider functions present in /sys/kernel/tracing/available_filter_functions. For system calls there is the s390 specific problem that the system call function itself is present via __se_sys##name() while the system call itself is wired up via an __s390x_sys##name() alias. The required DWARF debug information however is only available for the original function, not the alias, but within available_filter_functions only the functions with __s390x_ prefix are available. Which means the required DWARF debug information cannot be found. While this could be solved via tooling, it is easier to change the s390 specific system call wrapper handling. Therefore get rid of this alias handling and implement system call wrappers like most other architectures are doing. In result the implementation generates the following functions: long __s390x_sys##name(struct pt_regs *regs) static inline long __se_sys##name(...) static inline long __do_sys##name(...) __s390x_sys##name() is the visible system call function which is also wired up in the system call table. Its only parameter is a pt_regs variable. This function calls the corresponding __se_sys##name() function, which has as many parameters like the system call definition. This function in turn performs all zero and sign extensions of all system call parameters, taken from the pt_regs structure, and finally calls __do_sys##name(). __do_sys##name() is the actual inlined system call function implementation. For all 64 bit system calls there is a 31/32 bit system call function __s390_sys##name() generated, which handles all system call parameters correctly as required by compat handling. This function may be wired up within the compat system call table, unless there exists an explicit compat system call function, which is then used instead. Reported-by: Ilya Leoshkevich Tested-by: Ilya Leoshkevich Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens

s390/syscalls: remove trailing semicolon

2023-01-25T19:51:11+00:00

Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens

s390/syscalls: move __S390_SYS_STUBx() macro

2023-01-25T19:51:11+00:00

Move __S390_SYS_STUBx() the end of the CONFIG_COMPAT section, so both variants (compat and non-compat) are close together and can be easily compared. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens

s390/syscalls: remove __SC_COMPAT_TYPE define

2023-01-25T19:51:11+00:00

Remove __SC_COMPAT_TYPE define which is an unused leftover. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens

s390/syscalls: remove SYSCALL_METADATA() from compat syscalls

2023-01-25T19:51:11+00:00

SYSCALL_METADATA() is only supposed to be used for non-compat system calls. Otherwise there would be a name clash. This also removes the inconsistency that s390 is the only architecture which uses SYSCALL_METADATA() for compat system calls, and even that only for compat system calls without parameters. Only two such compat system calls exist. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens

s390: fix typo in syscall_wrapper.h

2022-03-27T20:18:38+00:00

Looks like this endif comment was erroneously unchanged when copied over from the x86 version. Signed-off-by: Russell Currey Link: https://lore.kernel.org/r/20220304090109.29386-1-ruscur@russell.cc Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: pass struct pt_regs instead of registers to syscalls

2021-01-19T11:29:27+00:00

Instead of fetching all registers from struct pt_regs and passing them to the syscall wrappers, let the system call wrappers only fetch the values really required. Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik