manifest

@@ -20,10 +20,11 @@
  */
 
 /*
  * Copyright 2015 Joyent, Inc.
  * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
+ * Copyright 2023 Oxide Computer Company
  *
  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 

@@ -84,18 +85,19 @@
         ucontext_t      *uc_link;
         sigset_t        uc_sigmask;
         stack_t         uc_stack;
         mcontext_t      uc_mcontext;
         /*
-         * The Intel386 ABI specification includes a 5-element array of longs
-         * called "uc_filler", padding the size of the struct to 512 bytes.  To
-         * allow zone brands to communicate extra data right the way through
-         * the signal handling process, from sigacthandler to setcontext, we
-         * steal the first three of these longs as a brand-private member.
+         * The first three entries have been borrowed by the lx brand right now.
+         * That should be consolidated into a single uc_brand entry with a
+         * UC_BRAND flag. Until such time, we leave them as is.
+         *
+         * We rename those first three entries here for SmartOS.
          */
         void            *uc_brand_data[3];
-        long            uc_filler[2];
+        long            uc_xsave;
+        long            uc_filler1;
 };
 #if defined(_SYSCALL32)
 
 /* Kernel view of user ILP32 ucontext structure */
 

@@ -104,11 +106,12 @@
         caddr32_t       uc_link;
         sigset_t        uc_sigmask;
         stack32_t       uc_stack;
         mcontext32_t    uc_mcontext;
         caddr32_t       uc_brand_data[3];
-        int32_t         uc_filler[2];
+        int32_t         uc_xsave;
+        int32_t         uc_filler1;
 } ucontext32_t;
 
 #if defined(_KERNEL)
 extern void ucontext_nto32(const ucontext_t *src, ucontext32_t *dest);
 extern void ucontext_32ton(const ucontext32_t *src, ucontext_t *dest);

@@ -119,10 +122,11 @@
 #if !defined(_XPG4_2) || defined(__EXTENSIONS__)
 #define GETCONTEXT      0
 #define SETCONTEXT      1
 #define GETUSTACK       2
 #define SETUSTACK       3
+#define GETCONTEXT_EXTD 4
 
 /*
  * values for uc_flags
  * these are implementation dependent flags, that should be hidden
  * from the user interface, defining which elements of ucontext

@@ -132,10 +136,11 @@
 #define UC_SIGMASK      0x01
 #define UC_STACK        0x02
 #define UC_CPU          0x04
 #define UC_MAU          0x08
 #define UC_FPU          UC_MAU
+#define UC_XSAVE        0x10
 
 #define UC_MCONTEXT     (UC_CPU|UC_FPU)
 
 /*
  * UC_ALL specifies the default context

@@ -143,15 +148,48 @@
 
 #define UC_ALL          (UC_SIGMASK|UC_STACK|UC_MCONTEXT)
 #endif /* !defined(_XPG4_2) || defined(__EXTENSIONS__) */
 
 #ifdef _KERNEL
-void savecontext(ucontext_t *, const k_sigset_t *);
+/*
+ * This structure is the private header for the xsave data that we end up
+ * sending to the stack. This is basically our own compressed form. See,
+ * uts/intel/os/fpu.c for more information.
+ */
+#define UC_XSAVE_VERS   (('u' << 24) | ('c' << 16) | 0x01)
+typedef struct uc_xsave {
+        uint32_t ucx_vers;
+        uint32_t ucx_len;
+        uint64_t ucx_bv;
+} uc_xsave_t;
+
+typedef enum {
+        /*
+         * Do a boring old savecontext() where we assume that only the data
+         * structure that we're given must be filled in.
+         */
+        SAVECTXT_F_NONE = 0,
+        /*
+         * Indicate that we should treat the ucontext_t as having valid user
+         * pointers for copying out extended state. Currently this means that we
+         * treat the uc_xsave member as something that points to a user address.
+         */
+        SAVECTXT_F_EXTD = 1 << 0,
+        /*
+         * This indicates that we shouldn't do normal copyout handling and need
+         * to actually avoid potentially triggering a watchpoint because we're
+         * probably in signal handling context.
+         */
+        SAVECTXT_F_ONFAULT = 1 << 1
+} savecontext_flags_t;
+
+int savecontext(ucontext_t *, const k_sigset_t *, savecontext_flags_t);
 void restorecontext(ucontext_t *);
 
 #ifdef _SYSCALL32
-extern void savecontext32(ucontext32_t *, const k_sigset_t *);
+extern int savecontext32(ucontext32_t *, const k_sigset_t *,
+    savecontext_flags_t);
 #endif
 #endif
 
 #ifdef  __cplusplus
 }