mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Denys Vlasenko <dvlasenk@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Denys Vlasenko <dvlasenk@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Oleg Nesterov <oleg@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	Andy Lutomirski <luto@amacapital.net>,
	Frederic Weisbecker <fweisbec@gmail.com>, X86 ML <x86@kernel.org>,
	Alexei Starovoitov <ast@plumgrid.com>,
	Will Drewry <wad@chromium.org>, Kees Cook <keescook@chromium.org>
Subject: [PATCH 09/17] x86: entry_64.S: move save_paranoid and ret_from_fork closer to their users
Date: Fri,  8 Aug 2014 19:44:32 +0200	[thread overview]
Message-ID: <1407519880-6719-10-git-send-email-dvlasenk@redhat.com> (raw)
In-Reply-To: <1407519880-6719-1-git-send-email-dvlasenk@redhat.com>

For some odd reasons, these two functions are at the very top of the file,
whereas their callers are approximately in the middle of it.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Oleg Nesterov <oleg@redhat.com>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: X86 ML <x86@kernel.org>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: linux-kernel@vger.kernel.org
---
 arch/x86/kernel/entry_64.S | 106 ++++++++++++++++++++++-----------------------
 1 file changed, 53 insertions(+), 53 deletions(-)

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 4a2e3ab..5ad9b28 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -202,59 +202,6 @@ ENDPROC(native_usergs_sysret64)
 	CFI_REL_OFFSET r15, R15+\offset
 	.endm
 
-ENTRY(save_paranoid)
-	XCPT_FRAME 1 RDI+8
-	cld
-	SAVE_C_REGS 8
-	SAVE_EXTRA_REGS 8
-	movl $1,%ebx
-	movl $MSR_GS_BASE,%ecx
-	rdmsr
-	testl %edx,%edx
-	js 1f	/* negative -> in kernel */
-	SWAPGS
-	xorl %ebx,%ebx
-1:	ret
-	CFI_ENDPROC
-END(save_paranoid)
-
-/*
- * A newly forked process directly context switches into this address.
- *
- * rdi: prev task we switched from
- */
-ENTRY(ret_from_fork)
-	DEFAULT_FRAME
-
-	LOCK ; btr $TIF_FORK,TI_flags(%r8)
-
-	pushq_cfi $0x0002
-	popfq_cfi				# reset kernel eflags
-
-	call schedule_tail			# rdi: 'prev' task parameter
-
-	GET_THREAD_INFO(%rcx)
-
-	RESTORE_EXTRA_REGS
-
-	testl $3, CS(%rsp)			# from kernel_thread?
-	jz   1f
-
-	testl $_TIF_IA32, TI_flags(%rcx)	# 32-bit compat task needs IRET
-	jnz  int_ret_from_sys_call
-
-	RESTORE_TOP_OF_STACK %rdi
-	jmp ret_from_sys_call			# go to the SYSRET fastpath
-
-1:
-	movq %rbp, %rdi
-	call *%rbx
-	movl $0, RAX(%rsp)
-	RESTORE_EXTRA_REGS
-	jmp int_ret_from_sys_call
-	CFI_ENDPROC
-END(ret_from_fork)
-
 /*
  * 64bit SYSCALL instruction entry. Up to 6 arguments in registers.
  *
@@ -608,6 +555,43 @@ END(stub_x32_execve)
 #endif
 
 /*
+ * A newly forked process directly context switches into this address.
+ *
+ * rdi: prev task we switched from
+ */
+ENTRY(ret_from_fork)
+	DEFAULT_FRAME
+
+	LOCK ; btr $TIF_FORK,TI_flags(%r8)
+
+	pushq_cfi $0x0002
+	popfq_cfi				# reset kernel eflags
+
+	call schedule_tail			# rdi: 'prev' task parameter
+
+	GET_THREAD_INFO(%rcx)
+
+	RESTORE_EXTRA_REGS
+
+	testl $3, CS(%rsp)			# from kernel_thread?
+	jz   1f
+
+	testl $_TIF_IA32, TI_flags(%rcx)	# 32-bit compat task needs IRET
+	jnz  int_ret_from_sys_call
+
+	RESTORE_TOP_OF_STACK %rdi
+	jmp ret_from_sys_call			# go to the SYSRET fastpath
+
+1:
+	movq %rbp, %rdi
+	call *%rbx
+	movl $0, RAX(%rsp)
+	RESTORE_EXTRA_REGS
+	jmp int_ret_from_sys_call
+	CFI_ENDPROC
+END(ret_from_fork)
+
+/*
  * Build the entry stubs and pointer table with some assembler magic.
  * We pack 7 stubs into a single 32-byte chunk, which will fit in a
  * single cache line on all modern x86 implementations.
@@ -1258,6 +1242,22 @@ idtentry async_page_fault do_async_page_fault has_error_code=1
 idtentry machine_check has_error_code=0 paranoid=1 do_sym=*machine_check_vector(%rip)
 #endif
 
+ENTRY(save_paranoid)
+	XCPT_FRAME 1 RDI+8
+	cld
+	SAVE_C_REGS 8
+	SAVE_EXTRA_REGS 8
+	movl $1,%ebx
+	movl $MSR_GS_BASE,%ecx
+	rdmsr
+	testl %edx,%edx
+	js 1f	/* negative -> in kernel */
+	SWAPGS
+	xorl %ebx,%ebx
+1:	ret
+	CFI_ENDPROC
+END(save_paranoid)
+
 	/*
 	 * "Paranoid" exit path from exception stack.
 	 * Paranoid because this is used by NMIs and cannot take
-- 
1.8.1.4


  parent reply	other threads:[~2014-08-08 17:45 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-08 17:44 [PATCH v4 0/17] x86: entry.S optimizations Denys Vlasenko
2014-08-08 17:44 ` [PATCH 01/17] x86: entry_64.S: delete unused code Denys Vlasenko
2014-08-08 17:44 ` [PATCH 02/17] x86: ia32entry.S: fix wrong symbolic constant usage: R11->ARGOFFSET Denys Vlasenko
2014-08-08 17:44 ` [PATCH 03/17] x86: open-code register save/restore in trace_hardirqs thunks Denys Vlasenko
2014-08-08 17:44 ` [PATCH 04/17] x86: entry_64.S: fold SAVE_ARGS_IRQ macro into its sole user Denys Vlasenko
2014-08-08 17:44 ` [PATCH 05/17] x86: entry_64.S: always allocate complete "struct pt_regs" Denys Vlasenko
2014-08-08 17:44 ` [PATCH 06/17] x86: mass removal of ARGOFFSET Denys Vlasenko
2014-08-08 17:44 ` [PATCH 07/17] x86: rename some macros and labels, no code changes Denys Vlasenko
2014-08-08 17:44 ` [PATCH 08/17] x86: add comments about various syscall instructions, " Denys Vlasenko
2014-08-08 17:44 ` Denys Vlasenko [this message]
2014-08-08 17:44 ` [PATCH 10/17] x86: entry_64.S: rename save_paranoid to paranoid_entry, " Denys Vlasenko
2014-08-08 17:44 ` [PATCH 11/17] x86: entry_64.S: fold test_in_nmi macro into its only user Denys Vlasenko
2014-08-08 17:44 ` [PATCH 12/17] x86: get rid of KERNEL_STACK_OFFSET Denys Vlasenko
2014-08-08 17:44 ` [PATCH 13/17] x86: ia32entry.S: fold IA32_ARG_FIXUP macro into its callers Denys Vlasenko
2014-08-08 17:44 ` [PATCH 14/17] x86: ia32entry.S: use mov instead of push/pop where possible Denys Vlasenko
2014-08-08 17:44 ` [PATCH 15/17] x86: code shrink in paranoid_exit Denys Vlasenko
2014-08-08 17:44 ` [PATCH 16/17] x86: entry_64.S: trivial optimization for ENOSYS Denys Vlasenko
2014-08-08 22:48   ` Andy Lutomirski
2014-08-08 17:44 ` [PATCH 17/17] x86: simplify iret stack handling on SYSCALL64 fastpath Denys Vlasenko
2014-08-08 22:59   ` Andy Lutomirski
2014-08-10 15:00     ` Denys Vlasenko
2014-08-10 22:42       ` Andy Lutomirski
2014-08-11 12:24         ` Denys Vlasenko
2014-08-11 20:06           ` Andy Lutomirski
2014-08-12  9:21             ` Denys Vlasenko
2014-08-13  1:02               ` Andy Lutomirski
2014-08-10 18:47   ` [PATCH 17/17 v2] " Denys Vlasenko
2014-08-09  0:27 ` [PATCH v4 0/17] x86: entry.S optimizations H. Peter Anvin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1407519880-6719-10-git-send-email-dvlasenk@redhat.com \
    --to=dvlasenk@redhat.com \
    --cc=ast@plumgrid.com \
    --cc=fweisbec@gmail.com \
    --cc=hpa@zytor.com \
    --cc=keescook@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@amacapital.net \
    --cc=oleg@redhat.com \
    --cc=torvalds@linux-foundation.org \
    --cc=wad@chromium.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®