The patch titled x86-64: slightly streamline 32-bit syscall entry code has been added to the -mm tree. Its filename is x86-64-slightly-streamline-32-bit-syscall-entry-code.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: x86-64: slightly streamline 32-bit syscall entry code From: Jan Beulich <jbeulich@xxxxxxxxxx> Avoid updating registers or memory twice as well as needlessly loading or copying registers. Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/x86/ia32/ia32entry.S | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) diff -puN arch/x86/ia32/ia32entry.S~x86-64-slightly-streamline-32-bit-syscall-entry-code arch/x86/ia32/ia32entry.S --- a/arch/x86/ia32/ia32entry.S~x86-64-slightly-streamline-32-bit-syscall-entry-code +++ a/arch/x86/ia32/ia32entry.S @@ -39,11 +39,11 @@ .endm /* clobbers %eax */ - .macro CLEAR_RREGS + .macro CLEAR_RREGS _r9=rax xorl %eax,%eax movq %rax,R11(%rsp) movq %rax,R10(%rsp) - movq %rax,R9(%rsp) + movq %\_r9,R9(%rsp) movq %rax,R8(%rsp) .endm @@ -52,11 +52,10 @@ * We don't reload %eax because syscall_trace_enter() returned * the value it wants us to use in the table lookup. */ - .macro LOAD_ARGS32 offset - movl \offset(%rsp),%r11d - movl \offset+8(%rsp),%r10d + .macro LOAD_ARGS32 offset, _r9=0 + .if \_r9 movl \offset+16(%rsp),%r9d - movl \offset+24(%rsp),%r8d + .endif movl \offset+40(%rsp),%ecx movl \offset+48(%rsp),%edx movl \offset+56(%rsp),%esi @@ -145,7 +144,7 @@ ENTRY(ia32_sysenter_target) SAVE_ARGS 0,0,1 /* no need to do an access_ok check here because rbp has been 32bit zero extended */ -1: movl (%rbp),%r9d +1: movl (%rbp),%ebp .section __ex_table,"a" .quad 1b,ia32_badarg .previous @@ -157,7 +156,7 @@ ENTRY(ia32_sysenter_target) cmpl $(IA32_NR_syscalls-1),%eax ja ia32_badsys sysenter_do_call: - IA32_ARG_FIXUP 1 + IA32_ARG_FIXUP sysenter_dispatch: call *ia32_sys_call_table(,%rax,8) movq %rax,RAX-ARGOFFSET(%rsp) @@ -234,20 +233,17 @@ sysexit_audit: #endif sysenter_tracesys: - xchgl %r9d,%ebp #ifdef CONFIG_AUDITSYSCALL testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%r10) jz sysenter_auditsys #endif SAVE_REST CLEAR_RREGS - movq %r9,R9(%rsp) movq $-ENOSYS,RAX(%rsp)/* ptrace can change this for a bad syscall */ movq %rsp,%rdi /* &pt_regs -> arg1 */ call syscall_trace_enter LOAD_ARGS32 ARGOFFSET /* reload args from stack in case ptrace changed it */ RESTORE_REST - xchgl %ebp,%r9d cmpl $(IA32_NR_syscalls-1),%eax ja int_ret_from_sys_call /* sysenter_tracesys has set RAX(%rsp) */ jmp sysenter_do_call @@ -314,9 +310,9 @@ ENTRY(ia32_cstar_target) testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10) CFI_REMEMBER_STATE jnz cstar_tracesys -cstar_do_call: cmpl $IA32_NR_syscalls-1,%eax ja ia32_badsys +cstar_do_call: IA32_ARG_FIXUP 1 cstar_dispatch: call *ia32_sys_call_table(,%rax,8) @@ -357,15 +353,13 @@ cstar_tracesys: #endif xchgl %r9d,%ebp SAVE_REST - CLEAR_RREGS - movq %r9,R9(%rsp) + CLEAR_RREGS r9 movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */ movq %rsp,%rdi /* &pt_regs -> arg1 */ call syscall_trace_enter - LOAD_ARGS32 ARGOFFSET /* reload args from stack in case ptrace changed it */ + LOAD_ARGS32 ARGOFFSET, 1 /* reload args from stack in case ptrace changed it */ RESTORE_REST xchgl %ebp,%r9d - movl RSP-ARGOFFSET(%rsp), %r8d cmpl $(IA32_NR_syscalls-1),%eax ja int_ret_from_sys_call /* cstar_tracesys has set RAX(%rsp) */ jmp cstar_do_call _ Patches currently in -mm which might be from jbeulich@xxxxxxxxxx are linux-next.patch x86-init-annotations-in-early_printk-setup.patch x86-adjust-dependencies-for-config_x86_cmov.patch x86-pgd_cdtor-cleanup.patch x86-x86_physvirt_bits-field-also-for-i386.patch x86-adjust-vmalloc_sync_all-for-xen-2nd-try.patch x86-fix-ticket-spin-lock-asm-constraints.patch x86-64-reduce-boot-fixmap-space.patch x86-64-add-two-__cpuinit-annotations.patch x86-64-eliminate-dead-code.patch x86-64-slightly-streamline-32-bit-syscall-entry-code.patch adjust-init-section-definitions.patch kconfig-eliminate-def_bool-n-constructs.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html