Skip site navigation (1)Skip section navigation (2) 
Date:      Sat, 13 Apr 2013 19:59:55 +0000 (UTC)
From:      Dmitry Chagin <dchagin@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-user@freebsd.org
Subject:   svn commit: r249442 - user/dchagin/lemul/sys/amd64/linux32
Message-ID:  <201304131959.r3DJxtvf069191@svn.freebsd.org>
next in thread | raw e-mail | index | archive | help 
Author: dchagin
Date: Sat Apr 13 19:59:54 2013
New Revision: 249442
URL: http://svnweb.freebsd.org/changeset/base/249442

Log:
  Put linux_platform into the vdso to avoid copying it onto the stack at
  every exec.

Modified:
  user/dchagin/lemul/sys/amd64/linux32/linux32_locore.s
  user/dchagin/lemul/sys/amd64/linux32/linux32_sysvec.c
  user/dchagin/lemul/sys/amd64/linux32/linux32_vdso.lds.s

Modified: user/dchagin/lemul/sys/amd64/linux32/linux32_locore.s
==============================================================================
--- user/dchagin/lemul/sys/amd64/linux32/linux32_locore.s	Sat Apr 13 19:58:24 2013	(r249441)
+++ user/dchagin/lemul/sys/amd64/linux32/linux32_locore.s	Sat Apr 13 19:59:54 2013	(r249442)
@@ -5,6 +5,12 @@
 
 #include <amd64/linux32/linux32_syscall.h>	/* system call numbers */
 
+.data
+
+	.globl linux_platform
+linux_platform:
+	.asciz "i686"
+
 .text
 .code32
 

Modified: user/dchagin/lemul/sys/amd64/linux32/linux32_sysvec.c
==============================================================================
--- user/dchagin/lemul/sys/amd64/linux32/linux32_sysvec.c	Sat Apr 13 19:58:24 2013	(r249441)
+++ user/dchagin/lemul/sys/amd64/linux32/linux32_sysvec.c	Sat Apr 13 19:59:54 2013	(r249442)
@@ -110,8 +110,6 @@ MALLOC_DEFINE(M_LINUX, "linux", "Linux m
 #define	LINUX_SYS_linux_rt_sendsig	0
 #define	LINUX_SYS_linux_sendsig		0
 
-const char *linux_platform = "i686";
-static int linux_szplatform;
 static int linux_szsigcode;
 static vm_object_t linux_shared_page_obj;
 static char *linux_shared_page_mapping;
@@ -228,6 +226,7 @@ struct linux32_ps_strings {
 LINUX_VDSO_SYM_INTPTR(linux32_sigcode);
 LINUX_VDSO_SYM_INTPTR(linux32_rt_sigcode);
 LINUX_VDSO_SYM_INTPTR(linux32_vsyscall);
+LINUX_VDSO_SYM_CHAR(linux_platform);
 
 /*
  * If FreeBSD & Linux have a difference of opinion about what a trap
@@ -256,11 +255,10 @@ elf_linux_fixup(register_t **stack_base,
 {
 	Elf32_Auxargs *args;
 	Elf32_Addr *base;
-	Elf32_Addr *pos, *uplatform;
+	Elf32_Addr *pos;
 	struct linux32_ps_strings *arginfo;
 
 	arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS;
-	uplatform = (Elf32_Addr *)((caddr_t)arginfo - linux_szplatform);
 
 	KASSERT(curthread->td_proc == imgp->proc,
 	    ("unsafe elf_linux_fixup(), should be curproc"));
@@ -295,7 +293,7 @@ elf_linux_fixup(register_t **stack_base,
 	AUXARGS_ENTRY_32(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
 	AUXARGS_ENTRY_32(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
 	AUXARGS_ENTRY_32(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
-	AUXARGS_ENTRY_32(pos, LINUX_AT_PLATFORM, PTROUT(uplatform));
+	AUXARGS_ENTRY_32(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
 	if (args->execfd != -1)
 		AUXARGS_ENTRY_32(pos, AT_EXECFD, args->execfd);
 	AUXARGS_ENTRY_32(pos, AT_NULL, 0);
@@ -903,15 +901,8 @@ linux_copyout_strings(struct image_param
 	 * Also deal with signal trampoline code for this exec type.
 	 */
 	arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS;
-	destp =	(caddr_t)arginfo - SPARE_USRSPACE - linux_szplatform -
-	    roundup((ARG_MAX - imgp->args->stringspace),
-	    sizeof(char *));
-
-	/*
-	 * Install LINUX_PLATFORM
-	 */
-	copyout(linux_platform, ((caddr_t)arginfo - linux_szplatform),
-	    linux_szplatform);
+	destp =	(caddr_t)arginfo - SPARE_USRSPACE -
+	    roundup((ARG_MAX - imgp->args->stringspace), sizeof(char *));
 
 	/*
 	 * If we have a valid auxargs ptr, prepare some room
@@ -1199,8 +1190,6 @@ linux_elf_modevent(module_t mod, int typ
 			    linux_proc_exec, NULL, 1000);
 			linux_thread_dtor_tag = EVENTHANDLER_REGISTER(thread_dtor,
 			    linux_thread_dtor, NULL, EVENTHANDLER_PRI_ANY);
-			linux_szplatform = roundup(strlen(linux_platform) + 1,
-			    sizeof(char *));
 			linux_osd_jail_register();
 			stclohz = (stathz ? stathz : hz);
 			if (bootverbose)

Modified: user/dchagin/lemul/sys/amd64/linux32/linux32_vdso.lds.s
==============================================================================
--- user/dchagin/lemul/sys/amd64/linux32/linux32_vdso.lds.s	Sat Apr 13 19:58:24 2013	(r249441)
+++ user/dchagin/lemul/sys/amd64/linux32/linux32_vdso.lds.s	Sat Apr 13 19:59:54 2013	(r249442)
@@ -60,6 +60,7 @@ VERSION
 		linux32_vsyscall;
 		linux32_sigcode;
 		linux32_rt_sigcode;
+		linux_platform;
 	local: *;
 	};
 }

Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201304131959.r3DJxtvf069191>