[src/trunk]: src/sys/arch Add a redzone between the pcb and the stack. Sent t...

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/06ad75229773
branches:  trunk
changeset: 970242:06ad75229773
user:      maxv <maxv%NetBSD.org@localhost>
date:      Tue Mar 17 17:18:49 2020 +0000

description:
Add a redzone between the pcb and the stack. Sent to port-amd64@.

diffstat:

 sys/arch/amd64/include/cpu.h   |   5 ++++-
 sys/arch/amd64/include/param.h |   6 ++----
 sys/arch/amd64/include/pcb.h   |   6 +++++-
 sys/arch/amd64/include/types.h |   3 ++-
 sys/arch/x86/x86/vm_machdep.c  |  38 ++++++++++++++++++++++++++++++--------
 5 files changed, 43 insertions(+), 15 deletions(-)

diffs (140 lines):

diff -r 253b6f8d0ba9 -r 06ad75229773 sys/arch/amd64/include/cpu.h
--- a/sys/arch/amd64/include/cpu.h      Tue Mar 17 17:16:26 2020 +0000
+++ b/sys/arch/amd64/include/cpu.h      Tue Mar 17 17:18:49 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cpu.h,v 1.67 2019/12/08 11:53:54 maxv Exp $    */
+/*     $NetBSD: cpu.h,v 1.68 2020/03/17 17:18:49 maxv Exp $    */
 
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
@@ -84,6 +84,9 @@
 #define CLKF_INTR(frame)       (curcpu()->ci_idepth > 0)
 #define LWP_PC(l)              ((l)->l_md.md_regs->tf_rip)
 
+void *cpu_uarea_alloc(bool);           
+bool cpu_uarea_free(void *);
+
 #endif /* _KERNEL */
 
 #else  /*      __x86_64__      */
diff -r 253b6f8d0ba9 -r 06ad75229773 sys/arch/amd64/include/param.h
--- a/sys/arch/amd64/include/param.h    Tue Mar 17 17:16:26 2020 +0000
+++ b/sys/arch/amd64/include/param.h    Tue Mar 17 17:18:49 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: param.h,v 1.36 2020/02/08 07:07:07 maxv Exp $  */
+/*     $NetBSD: param.h,v 1.37 2020/03/17 17:18:49 maxv Exp $  */
 
 #ifdef __x86_64__
 
@@ -69,10 +69,8 @@
 
 #if defined(KASAN) || defined(KMSAN)
 #define        UPAGES          8
-#elif defined(DIAGNOSTIC)
+#else
 #define        UPAGES          5               /* pages of u-area (1 for redzone) */
-#else
-#define        UPAGES          4               /* pages of u-area */
 #endif
 #define        USPACE          (UPAGES * NBPG) /* total size of u-area */
 
diff -r 253b6f8d0ba9 -r 06ad75229773 sys/arch/amd64/include/pcb.h
--- a/sys/arch/amd64/include/pcb.h      Tue Mar 17 17:16:26 2020 +0000
+++ b/sys/arch/amd64/include/pcb.h      Tue Mar 17 17:18:49 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pcb.h,v 1.31 2019/10/12 15:44:46 christos Exp $        */
+/*     $NetBSD: pcb.h,v 1.32 2020/03/17 17:18:49 maxv Exp $    */
 
 /*
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -77,6 +77,10 @@
 
 #define        NIOPORTS        1024            /* # of ports we allow to be mapped */
 
+/*
+ * IMPORTANT NOTE: this structure, including the variable-sized FPU state at
+ * the end, must fit within one page.
+ */
 struct pcb {
        int       pcb_flags;
 #define        PCB_COMPAT32    0x01
diff -r 253b6f8d0ba9 -r 06ad75229773 sys/arch/amd64/include/types.h
--- a/sys/arch/amd64/include/types.h    Tue Mar 17 17:16:26 2020 +0000
+++ b/sys/arch/amd64/include/types.h    Tue Mar 17 17:18:49 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: types.h,v 1.64 2019/11/14 16:23:52 maxv Exp $  */
+/*     $NetBSD: types.h,v 1.65 2020/03/17 17:18:49 maxv Exp $  */
 
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
@@ -116,6 +116,7 @@
 #define        __HAVE_PCPU_AREA 1
 #define        __HAVE_DIRECT_MAP 1
 #endif
+#define        __HAVE_CPU_UAREA_ROUTINES 1
 #if !defined(NO_PCI_MSI_MSIX)
 #define        __HAVE_PCI_MSI_MSIX
 #endif
diff -r 253b6f8d0ba9 -r 06ad75229773 sys/arch/x86/x86/vm_machdep.c
--- a/sys/arch/x86/x86/vm_machdep.c     Tue Mar 17 17:16:26 2020 +0000
+++ b/sys/arch/x86/x86/vm_machdep.c     Tue Mar 17 17:18:49 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vm_machdep.c,v 1.41 2020/01/25 15:38:24 ad Exp $       */
+/*     $NetBSD: vm_machdep.c,v 1.42 2020/03/17 17:18:49 maxv Exp $     */
 
 /*-
  * Copyright (c) 1982, 1986 The Regents of the University of California.
@@ -80,7 +80,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.41 2020/01/25 15:38:24 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.42 2020/03/17 17:18:49 maxv Exp $");
 
 #include "opt_mtrr.h"
 
@@ -194,12 +194,6 @@
        /* Child LWP might get aston() before returning to userspace. */
        tf->tf_trapno = T_ASTFLT;
 
-#if 0 /* DIAGNOSTIC */
-       /* Set a red zone in the kernel stack after the uarea. */
-       pmap_kremove(uv, PAGE_SIZE);
-       pmap_update(pmap_kernel());
-#endif
-
        /* If specified, set a different user stack for a child. */
        if (stack != NULL) {
 #ifdef __x86_64__
@@ -353,3 +347,31 @@
        bp->b_data = bp->b_saveaddr;
        bp->b_saveaddr = 0;
 }
+
+#ifdef __HAVE_CPU_UAREA_ROUTINES
+void *
+cpu_uarea_alloc(bool system)
+{
+       vaddr_t va;
+
+       va = uvm_km_alloc(kernel_map, USPACE, 0, UVM_KMF_WIRED|UVM_KMF_WAITVA);
+       if (va == 0)
+               return NULL;
+
+       /*
+        * The second page is unmapped, and acts as a guard page between the
+        * PCB (first page) and the stack (rest of the pages).
+        */
+       pmap_kremove(va + PAGE_SIZE, PAGE_SIZE);
+       pmap_update(pmap_kernel());
+
+       return (void *)va;
+}
+
+bool
+cpu_uarea_free(void *addr)
+{
+       uvm_km_free(kernel_map, (vaddr_t)addr, USPACE, UVM_KMF_WIRED);
+       return true;
+}
+#endif /* __HAVE_CPU_UAREA_ROUTINES */