b35f549df1
At Linux Plumbers, Andy Lutomirski approached me and pointed out that the function call syscall_get_arguments() implemented in x86 was horribly written and not optimized for the standard case of passing in 0 and 6 for the starting index and the number of system calls to get. When looking at all the users of this function, I discovered that all instances pass in only 0 and 6 for these arguments. Instead of having this function handle different cases that are never used, simply rewrite it to return the first 6 arguments of a system call. This should help out the performance of tracing system calls by ptrace, ftrace and perf. Link: http://lkml.kernel.org/r/20161107213233.754809394@goodmis.org Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Dave Martin <dave.martin@arm.com> Cc: "Dmitry V. Levin" <ldv@altlinux.org> Cc: x86@kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: uclinux-h8-devel@lists.sourceforge.jp Cc: linux-hexagon@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-mips@vger.kernel.org Cc: nios2-dev@lists.rocketboards.org Cc: openrisc@lists.librecores.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-riscv@lists.infradead.org Cc: linux-s390@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: sparclinux@vger.kernel.org Cc: linux-um@lists.infradead.org Cc: linux-xtensa@linux-xtensa.org Cc: linux-arch@vger.kernel.org Acked-by: Paul Burton <paul.burton@mips.com> # MIPS parts Acked-by: Max Filippov <jcmvbkbc@gmail.com> # For xtensa changes Acked-by: Will Deacon <will.deacon@arm.com> # For the arm64 bits Reviewed-by: Thomas Gleixner <tglx@linutronix.de> # for x86 Reviewed-by: Dmitry V. Levin <ldv@altlinux.org> Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> |
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| .. | ||
| arcregs.h | ||
| asm-offsets.h | ||
| atomic.h | ||
| barrier.h | ||
| bitops.h | ||
| bug.h | ||
| cache.h | ||
| cacheflush.h | ||
| checksum.h | ||
| cmpxchg.h | ||
| current.h | ||
| delay.h | ||
| disasm.h | ||
| dma.h | ||
| dwarf.h | ||
| elf.h | ||
| entry-arcv2.h | ||
| entry-compact.h | ||
| entry.h | ||
| exec.h | ||
| fb.h | ||
| futex.h | ||
| highmem.h | ||
| hugepage.h | ||
| io.h | ||
| irq.h | ||
| irqflags-arcv2.h | ||
| irqflags-compact.h | ||
| irqflags.h | ||
| Kbuild | ||
| kdebug.h | ||
| kgdb.h | ||
| kmap_types.h | ||
| kprobes.h | ||
| linkage.h | ||
| mach_desc.h | ||
| mmu.h | ||
| mmu_context.h | ||
| mmzone.h | ||
| module.h | ||
| page.h | ||
| pci.h | ||
| perf_event.h | ||
| pgalloc.h | ||
| pgtable.h | ||
| processor.h | ||
| ptrace.h | ||
| sections.h | ||
| segment.h | ||
| serial.h | ||
| setup.h | ||
| shmparam.h | ||
| smp.h | ||
| spinlock.h | ||
| spinlock_types.h | ||
| stacktrace.h | ||
| string.h | ||
| switch_to.h | ||
| syscall.h | ||
| syscalls.h | ||
| thread_info.h | ||
| timex.h | ||
| tlb-mmu1.h | ||
| tlb.h | ||
| tlbflush.h | ||
| uaccess.h | ||
| unaligned.h | ||
| unwind.h | ||