linux/arch/s390
Heiko Carstens 2213d44e14 s390/syscalls: get rid of system call alias functions
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 <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-25 20:51:11 +01:00
..
appldata s390/appldata: remove power management callbacks 2022-12-02 18:25:04 +01:00
boot Merge branch 'fixes' into features 2023-01-17 19:12:39 +01:00
configs s390: update defconfigs 2023-01-11 21:26:40 +01:00
crypto s390/archrandom: add missing header include 2023-01-10 14:39:08 +01:00
hypfs s390/hypfs: remove unused info_blk_hdr__pcpus() function 2022-11-23 16:24:07 +01:00
include s390/syscalls: get rid of system call alias functions 2023-01-25 20:51:11 +01:00
kernel s390: discard .interp section 2023-01-25 20:51:10 +01:00
kvm KVM: s390: interrupt: use READ_ONCE() before cmpxchg() 2023-01-11 15:28:47 +01:00
lib s390/kprobes: replace kretprobe with rethook 2023-01-22 18:42:35 +01:00
mm s390/vmem: use swap() instead of open coding it 2023-01-22 18:42:34 +01:00
net s390/bpf: Fix typo in comment 2022-05-23 11:25:53 -07:00
pci IOMMU Updates for Linux v6.2 2022-12-19 08:34:39 -06:00
purgatory s390/purgatory: remove duplicated build rule of kexec-purgatory.o 2022-06-30 14:18:16 +02:00
tools KVM: s390: Add facility 197 to the allow list 2022-07-13 15:25:25 +02:00
Kbuild
Kconfig s390/kprobes: replace kretprobe with rethook 2023-01-22 18:42:35 +01:00
Kconfig.debug s390/Kconfig.debug: fix indentation 2022-06-01 12:03:15 +02:00
Makefile s390: always build relocatable kernel 2022-11-08 19:32:32 +01:00