svn commit: r217151 - in head/sys: amd64/amd64 amd64/ia32 amd64/include compat/freebsd32 compat/ia32 kern sys

Konstantin Belousov kib at FreeBSD.org
Sat Jan 8 16:13:45 UTC 2011


Author: kib
Date: Sat Jan  8 16:13:44 2011
New Revision: 217151
URL: http://svn.freebsd.org/changeset/base/217151

Log:
  Create shared (readonly) page. Each ABI may specify the use of page by
  setting SV_SHP flag and providing pointer to the vm object and mapping
  address. Provide simple allocator to carve space in the page, tailored
  to put the code with alignment restrictions.
  
  Enable shared page use for amd64, both native and 32bit FreeBSD
  binaries.  Page is private mapped at the top of the user address
  space, moving a start of the stack one page down. Move signal
  trampoline code from the top of the stack to the shared page.
  
  Reviewed by:	 alc

Modified:
  head/sys/amd64/amd64/elf_machdep.c
  head/sys/amd64/amd64/machdep.c
  head/sys/amd64/ia32/ia32_signal.c
  head/sys/amd64/include/vmparam.h
  head/sys/compat/freebsd32/freebsd32_misc.c
  head/sys/compat/ia32/ia32_sysvec.c
  head/sys/compat/ia32/ia32_util.h
  head/sys/kern/kern_exec.c
  head/sys/sys/imgact.h
  head/sys/sys/sysent.h

Modified: head/sys/amd64/amd64/elf_machdep.c
==============================================================================
--- head/sys/amd64/amd64/elf_machdep.c	Sat Jan  8 16:02:14 2011	(r217150)
+++ head/sys/amd64/amd64/elf_machdep.c	Sat Jan  8 16:13:44 2011	(r217151)
@@ -75,11 +75,14 @@ struct sysentvec elf64_freebsd_sysvec = 
 	.sv_setregs	= exec_setregs,
 	.sv_fixlimit	= NULL,
 	.sv_maxssiz	= NULL,
-	.sv_flags	= SV_ABI_FREEBSD | SV_LP64,
+	.sv_flags	= SV_ABI_FREEBSD | SV_LP64 | SV_SHP,
 	.sv_set_syscall_retval = cpu_set_syscall_retval,
 	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
 	.sv_syscallnames = syscallnames,
+	.sv_shared_page_base = SHAREDPAGE,
+	.sv_shared_page_len = PAGE_SIZE,
 };
+INIT_SYSENTVEC(elf64_sysvec, &elf64_freebsd_sysvec);
 
 static Elf64_Brandinfo freebsd_brand_info = {
 	.brand		= ELFOSABI_FREEBSD,
@@ -129,7 +132,6 @@ SYSINIT(kelf64, SI_SUB_EXEC, SI_ORDER_AN
 	(sysinit_cfunc_t) elf64_insert_brand_entry,
 	&kfreebsd_brand_info);
 
-
 void
 elf64_dump_thread(struct thread *td __unused, void *dst __unused,
     size_t *off __unused)

Modified: head/sys/amd64/amd64/machdep.c
==============================================================================
--- head/sys/amd64/amd64/machdep.c	Sat Jan  8 16:02:14 2011	(r217150)
+++ head/sys/amd64/amd64/machdep.c	Sat Jan  8 16:13:44 2011	(r217151)
@@ -386,7 +386,7 @@ sendsig(sig_t catcher, ksiginfo_t *ksi, 
 	}
 
 	regs->tf_rsp = (long)sfp;
-	regs->tf_rip = PS_STRINGS - *(p->p_sysent->sv_szsigcode);
+	regs->tf_rip = p->p_sysent->sv_sigcode_base;
 	regs->tf_rflags &= ~(PSL_T | PSL_D);
 	regs->tf_cs = _ucodesel;
 	regs->tf_ds = _udatasel;

Modified: head/sys/amd64/ia32/ia32_signal.c
==============================================================================
--- head/sys/amd64/ia32/ia32_signal.c	Sat Jan  8 16:02:14 2011	(r217150)
+++ head/sys/amd64/ia32/ia32_signal.c	Sat Jan  8 16:13:44 2011	(r217151)
@@ -393,7 +393,8 @@ freebsd4_ia32_sendsig(sig_t catcher, ksi
 	}
 
 	regs->tf_rsp = (uintptr_t)sfp;
-	regs->tf_rip = p->p_sysent->sv_psstrings - sz_freebsd4_ia32_sigcode;
+	regs->tf_rip = p->p_sysent->sv_sigcode_base + sz_ia32_sigcode -
+	    sz_freebsd4_ia32_sigcode;
 	regs->tf_rflags &= ~(PSL_T | PSL_D);
 	regs->tf_cs = _ucode32sel;
 	regs->tf_ss = _udatasel;
@@ -514,7 +515,7 @@ ia32_sendsig(sig_t catcher, ksiginfo_t *
 	}
 
 	regs->tf_rsp = (uintptr_t)sfp;
-	regs->tf_rip = p->p_sysent->sv_psstrings - *(p->p_sysent->sv_szsigcode);
+	regs->tf_rip = p->p_sysent->sv_sigcode_base;
 	regs->tf_rflags &= ~(PSL_T | PSL_D);
 	regs->tf_cs = _ucode32sel;
 	regs->tf_ss = _udatasel;

Modified: head/sys/amd64/include/vmparam.h
==============================================================================
--- head/sys/amd64/include/vmparam.h	Sat Jan  8 16:02:14 2011	(r217150)
+++ head/sys/amd64/include/vmparam.h	Sat Jan  8 16:13:44 2011	(r217151)
@@ -186,7 +186,8 @@
 
 #define	VM_MAXUSER_ADDRESS	UVADDR(NUPML4E, 0, 0, 0)
 
-#define	USRSTACK		VM_MAXUSER_ADDRESS
+#define	SHAREDPAGE		(VM_MAXUSER_ADDRESS - PAGE_SIZE)
+#define	USRSTACK		SHAREDPAGE
 
 #define	VM_MAX_ADDRESS		UPT_MAX_ADDRESS
 #define	VM_MIN_ADDRESS		(0)

Modified: head/sys/compat/freebsd32/freebsd32_misc.c
==============================================================================
--- head/sys/compat/freebsd32/freebsd32_misc.c	Sat Jan  8 16:02:14 2011	(r217150)
+++ head/sys/compat/freebsd32/freebsd32_misc.c	Sat Jan  8 16:13:44 2011	(r217151)
@@ -2546,7 +2546,10 @@ freebsd32_copyout_strings(struct image_p
 		execpath_len = 0;
 	arginfo = (struct freebsd32_ps_strings *)curproc->p_sysent->
 	    sv_psstrings;
-	szsigcode = *(imgp->proc->p_sysent->sv_szsigcode);
+	if (imgp->proc->p_sysent->sv_sigcode_base == 0)
+		szsigcode = *(imgp->proc->p_sysent->sv_szsigcode);
+	else
+		szsigcode = 0;
 	destp =	(caddr_t)arginfo - szsigcode - SPARE_USRSPACE -
 	    roundup(execpath_len, sizeof(char *)) -
 	    roundup(sizeof(canary), sizeof(char *)) -
@@ -2556,7 +2559,7 @@ freebsd32_copyout_strings(struct image_p
 	/*
 	 * install sigcode
 	 */
-	if (szsigcode)
+	if (szsigcode != 0)
 		copyout(imgp->proc->p_sysent->sv_sigcode,
 			((caddr_t)arginfo - szsigcode), szsigcode);
 

Modified: head/sys/compat/ia32/ia32_sysvec.c
==============================================================================
--- head/sys/compat/ia32/ia32_sysvec.c	Sat Jan  8 16:02:14 2011	(r217150)
+++ head/sys/compat/ia32/ia32_sysvec.c	Sat Jan  8 16:13:44 2011	(r217151)
@@ -129,7 +129,7 @@ struct sysentvec ia32_freebsd_sysvec = {
 	.sv_minsigstksz	= MINSIGSTKSZ,
 	.sv_pagesize	= IA32_PAGE_SIZE,
 	.sv_minuser	= 0,
-	.sv_maxuser	= FREEBSD32_USRSTACK,
+	.sv_maxuser	= FREEBSD32_MAXUSER,
 	.sv_usrstack	= FREEBSD32_USRSTACK,
 	.sv_psstrings	= FREEBSD32_PS_STRINGS,
 	.sv_stackprot	= VM_PROT_ALL,
@@ -137,12 +137,20 @@ struct sysentvec ia32_freebsd_sysvec = {
 	.sv_setregs	= ia32_setregs,
 	.sv_fixlimit	= ia32_fixlimit,
 	.sv_maxssiz	= &ia32_maxssiz,
-	.sv_flags	= SV_ABI_FREEBSD | SV_IA32 | SV_ILP32,
+	.sv_flags	= SV_ABI_FREEBSD | SV_IA32 | SV_ILP32 |
+#ifdef __amd64__
+		SV_SHP
+#else
+		0
+#endif
+	,
 	.sv_set_syscall_retval = ia32_set_syscall_retval,
 	.sv_fetch_syscall_args = ia32_fetch_syscall_args,
 	.sv_syscallnames = freebsd32_syscallnames,
+	.sv_shared_page_base = FREEBSD32_SHAREDPAGE,
+	.sv_shared_page_len = PAGE_SIZE,
 };
-
+INIT_SYSENTVEC(elf_ia32_sysvec, &ia32_freebsd_sysvec);
 
 static Elf32_Brandinfo ia32_brand_info = {
 	.brand		= ELFOSABI_FREEBSD,
@@ -191,7 +199,6 @@ SYSINIT(kia32, SI_SUB_EXEC, SI_ORDER_ANY
 	(sysinit_cfunc_t) elf32_insert_brand_entry,
 	&kia32_brand_info);
 
-
 void
 elf32_dump_thread(struct thread *td __unused, void *dst __unused,
     size_t *off __unused)

Modified: head/sys/compat/ia32/ia32_util.h
==============================================================================
--- head/sys/compat/ia32/ia32_util.h	Sat Jan  8 16:02:14 2011	(r217150)
+++ head/sys/compat/ia32/ia32_util.h	Sat Jan  8 16:13:44 2011	(r217151)
@@ -41,9 +41,13 @@
 #include <sys/cdefs.h>
 
 #ifdef __ia64__
-#define FREEBSD32_USRSTACK	((1ul << 32) - IA32_PAGE_SIZE * 2)
+#define FREEBSD32_MAXUSER	((1ul << 32) - IA32_PAGE_SIZE * 2)
+#define	FREEBSD32_SHAREDPAGE	0
+#define FREEBSD32_USRSTACK	FREEBSD32_MAXUSER
 #else
-#define FREEBSD32_USRSTACK	((1ul << 32) - IA32_PAGE_SIZE)
+#define	FREEBSD32_MAXUSER	((1ul << 32) - IA32_PAGE_SIZE)
+#define	FREEBSD32_SHAREDPAGE	(FREEBSD32_MAXUSER - IA32_PAGE_SIZE)
+#define FREEBSD32_USRSTACK	FREEBSD32_SHAREDPAGE
 #endif
 
 #define	IA32_PAGE_SIZE	4096

Modified: head/sys/kern/kern_exec.c
==============================================================================
--- head/sys/kern/kern_exec.c	Sat Jan  8 16:02:14 2011	(r217150)
+++ head/sys/kern/kern_exec.c	Sat Jan  8 16:13:44 2011	(r217151)
@@ -389,6 +389,7 @@ do_execve(td, args, mac_p)
 	imgp->canarylen = 0;
 	imgp->pagesizes = 0;
 	imgp->pagesizeslen = 0;
+	imgp->stack_prot = 0;
 
 #ifdef MAC
 	error = mac_execve_enter(imgp, mac_p);
@@ -996,6 +997,7 @@ exec_new_vmspace(imgp, sv)
 	int error;
 	struct proc *p = imgp->proc;
 	struct vmspace *vmspace = p->p_vmspace;
+	vm_object_t obj;
 	vm_offset_t sv_minuser, stack_addr;
 	vm_map_t map;
 	u_long ssiz;
@@ -1029,6 +1031,20 @@ exec_new_vmspace(imgp, sv)
 		map = &vmspace->vm_map;
 	}
 
+	/* Map a shared page */
+	obj = sv->sv_shared_page_obj;
+	if (obj != NULL) {
+		vm_object_reference(obj);
+		error = vm_map_fixed(map, obj, 0,
+		    sv->sv_shared_page_base, sv->sv_shared_page_len,
+		    VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
+		    MAP_COPY_ON_WRITE | MAP_ACC_NO_CHARGE);
+		if (error) {
+			vm_object_deallocate(obj);
+			return (error);
+		}
+	}
+
 	/* Allocate a new stack */
 	if (sv->sv_maxssiz != NULL)
 		ssiz = *sv->sv_maxssiz;
@@ -1036,7 +1052,9 @@ exec_new_vmspace(imgp, sv)
 		ssiz = maxssiz;
 	stack_addr = sv->sv_usrstack - ssiz;
 	error = vm_map_stack(map, stack_addr, (vm_size_t)ssiz,
-	    sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_DOWN);
+	    obj != NULL && imgp->stack_prot != 0 ? imgp->stack_prot :
+		sv->sv_stackprot,
+	    VM_PROT_ALL, MAP_STACK_GROWS_DOWN);
 	if (error)
 		return (error);
 
@@ -1208,8 +1226,10 @@ exec_copyout_strings(imgp)
 	p = imgp->proc;
 	szsigcode = 0;
 	arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
-	if (p->p_sysent->sv_szsigcode != NULL)
-		szsigcode = *(p->p_sysent->sv_szsigcode);
+	if (p->p_sysent->sv_sigcode_base == 0) {
+		if (p->p_sysent->sv_szsigcode != NULL)
+			szsigcode = *(p->p_sysent->sv_szsigcode);
+	}
 	destp =	(caddr_t)arginfo - szsigcode - SPARE_USRSPACE -
 	    roundup(execpath_len, sizeof(char *)) -
 	    roundup(sizeof(canary), sizeof(char *)) -
@@ -1219,7 +1239,7 @@ exec_copyout_strings(imgp)
 	/*
 	 * install sigcode
 	 */
-	if (szsigcode)
+	if (szsigcode != 0)
 		copyout(p->p_sysent->sv_sigcode, ((caddr_t)arginfo -
 		    szsigcode), szsigcode);
 
@@ -1459,3 +1479,64 @@ exec_unregister(execsw_arg)
 	execsw = newexecsw;
 	return (0);
 }
+
+static vm_object_t shared_page_obj;
+static int shared_page_free;
+
+int
+shared_page_fill(int size, int align, const char *data)
+{
+	vm_page_t m;
+	struct sf_buf *s;
+	vm_offset_t sk;
+	int res;
+
+	VM_OBJECT_LOCK(shared_page_obj);
+	m = vm_page_grab(shared_page_obj, 0, VM_ALLOC_RETRY);
+	res = roundup(shared_page_free, align);
+	if (res + size >= IDX_TO_OFF(shared_page_obj->size))
+		res = -1;
+	else {
+		VM_OBJECT_UNLOCK(shared_page_obj);
+		s = sf_buf_alloc(m, SFB_DEFAULT);
+		sk = sf_buf_kva(s);
+		bcopy(data, (void *)(sk + res), size);
+		shared_page_free = res + size;
+		sf_buf_free(s);
+		VM_OBJECT_LOCK(shared_page_obj);
+	}
+	vm_page_wakeup(m);
+	VM_OBJECT_UNLOCK(shared_page_obj);
+	return (res);
+}
+
+static void
+shared_page_init(void *dummy __unused)
+{
+	vm_page_t m;
+
+	shared_page_obj = vm_pager_allocate(OBJT_PHYS, 0, PAGE_SIZE,
+	    VM_PROT_DEFAULT, 0, NULL);
+	VM_OBJECT_LOCK(shared_page_obj);
+	m = vm_page_grab(shared_page_obj, 0, VM_ALLOC_RETRY | VM_ALLOC_NOBUSY |
+	    VM_ALLOC_ZERO);
+	m->valid = VM_PAGE_BITS_ALL;
+	VM_OBJECT_UNLOCK(shared_page_obj);
+}
+
+SYSINIT(shp, SI_SUB_EXEC, SI_ORDER_FIRST, (sysinit_cfunc_t)shared_page_init,
+    NULL);
+
+void
+exec_sysvec_init(void *param)
+{
+	struct sysentvec *sv;
+
+	sv = (struct sysentvec *)param;
+
+	if ((sv->sv_flags & SV_SHP) == 0)
+		return;
+	sv->sv_shared_page_obj = shared_page_obj;
+	sv->sv_sigcode_base = sv->sv_shared_page_base +
+	    shared_page_fill(*(sv->sv_szsigcode), 16, sv->sv_sigcode);
+}

Modified: head/sys/sys/imgact.h
==============================================================================
--- head/sys/sys/imgact.h	Sat Jan  8 16:02:14 2011	(r217150)
+++ head/sys/sys/imgact.h	Sat Jan  8 16:13:44 2011	(r217151)
@@ -34,6 +34,8 @@
 
 #include <sys/uio.h>
 
+#include <vm/vm.h>
+
 #define MAXSHELLCMDLEN	PAGE_SIZE
 
 struct image_args {
@@ -75,6 +77,7 @@ struct image_params {
 	int canarylen;
 	unsigned long pagesizes;
 	int pagesizeslen;
+	vm_prot_t stack_prot;
 };
 
 #ifdef _KERNEL

Modified: head/sys/sys/sysent.h
==============================================================================
--- head/sys/sys/sysent.h	Sat Jan  8 16:02:14 2011	(r217150)
+++ head/sys/sys/sysent.h	Sat Jan  8 16:13:44 2011	(r217151)
@@ -116,12 +116,17 @@ struct sysentvec {
 	int		(*sv_fetch_syscall_args)(struct thread *, struct
 			    syscall_args *);
 	const char	**sv_syscallnames;
+	vm_offset_t	sv_shared_page_base;
+	vm_offset_t	sv_shared_page_len;
+	vm_offset_t	sv_sigcode_base;
+	void		*sv_shared_page_obj;
 };
 
 #define	SV_ILP32	0x000100
 #define	SV_LP64		0x000200
 #define	SV_IA32		0x004000
 #define	SV_AOUT		0x008000
+#define	SV_SHP		0x010000
 
 #define	SV_ABI_MASK	0xff
 #define	SV_CURPROC_FLAG(x) (curproc->p_sysent->sv_flags & (x))
@@ -222,6 +227,13 @@ int	lkmressys(struct thread *, struct no
 int	syscall_thread_enter(struct thread *td, struct sysent *se);
 void	syscall_thread_exit(struct thread *td, struct sysent *se);
 
+int shared_page_fill(int size, int align, const char *data);
+void exec_sysvec_init(void *param);
+
+#define INIT_SYSENTVEC(name, sv)					\
+    SYSINIT(name, SI_SUB_EXEC, SI_ORDER_ANY,				\
+	(sysinit_cfunc_t)exec_sysvec_init, sv);
+
 #endif /* _KERNEL */
 
 #endif /* !_SYS_SYSENT_H_ */


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