Linus Torvalds 970b766cfd Andy Lutomirski approached me to tell me that the syscall_get_arguments() ... implementation in x86 was horrible and gcc certainly gets it wrong. He said that since the tracepoints only pass in 0 and 6 for i and n repectively, it should be optimized for that case. Inspecting the kernel, I discovered that all users pass in 0 for i and only one file passing in something other than 6 for the number of arguments. That code happens to be my own code used for the special syscall tracing. That can easily be converted to just using 0 and 6 as well, and only copying what is needed. Which is probably the faster path anyway for that case. Along the way, a couple of real fixes came from this as the syscall_get_arguments() function was incorrect for csky and riscv. x86 has been optimized to for the new interface that removes the variable number of arguments, but the other architectures could still use some loving and take more advantage of the simpler interface. -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXKdi7RQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qjtiAQDaZbFaSgEbs99jjuAPDSZ0li8dyUOC 3KS5TyuLw+fEaAD/QZnKjplVFAfA5FxrABZ0ioIKDON4nLyESEb+xCv0gA4= =dTuo -----END PGP SIGNATURE----- Merge tag 'trace-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull syscall-get-arguments cleanup and fixes from Steven Rostedt: "Andy Lutomirski approached me to tell me that the syscall_get_arguments() implementation in x86 was horrible and gcc certainly gets it wrong. He said that since the tracepoints only pass in 0 and 6 for i and n repectively, it should be optimized for that case. Inspecting the kernel, I discovered that all users pass in 0 for i and only one file passing in something other than 6 for the number of arguments. That code happens to be my own code used for the special syscall tracing. That can easily be converted to just using 0 and 6 as well, and only copying what is needed. Which is probably the faster path anyway for that case. Along the way, a couple of real fixes came from this as the syscall_get_arguments() function was incorrect for csky and riscv. x86 has been optimized to for the new interface that removes the variable number of arguments, but the other architectures could still use some loving and take more advantage of the simpler interface" * tag 'trace-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: syscalls: Remove start and number from syscall_set_arguments() args syscalls: Remove start and number from syscall_get_arguments() args csky: Fix syscall_get_arguments() and syscall_set_arguments() riscv: Fix syscall_get_arguments() and syscall_set_arguments() tracing/syscalls: Pass in hardcoded 6 into syscall_get_arguments() ptrace: Remove maxargs from task_current_syscall()		2019-04-05 13:15:57 -10:00
..
boot	RISC-V: Build flat and compressed kernel images	2018-11-20 05:19:09 -08:00
configs	RISC-V: defconfig: Add CRYPTO_DEV_VIRTIO=y	2019-01-23 14:09:01 -08:00
include	Andy Lutomirski approached me to tell me that the syscall_get_arguments()	2019-04-05 13:15:57 -10:00
kernel	RISC-V: Use IS_ENABLED(CONFIG_CMODEL_MEDLOW)	2019-03-28 23:18:51 -07:00
lib	RISC-V: lib: minor asm cleanup	2018-12-21 08:17:02 -08:00
mm	RISC-V: Always compile mm/init.c with cmodel=medany and notrace	2019-03-26 18:25:06 -07:00
net	bpf, riscv: add BPF JIT for RV64G	2019-02-05 16:56:10 +01:00
Kconfig	DMA mapping updates for 5.1	2019-03-10 11:54:48 -07:00
Kconfig.debug	RISC-V: Remove EARLY_PRINTK support	2018-12-17 10:23:46 -08:00
Makefile	bpf, riscv: add BPF JIT for RV64G	2019-02-05 16:56:10 +01:00