Sync libkvm interface with FSF repository. This adds new "kvm proc" and

"kvm pcb" commands.
ok deraadt@

6 files changed, 162 insertions, 26 deletions

diff --git a/gnu/usr.bin/binutils/gdb/amd64obsd-nat.c b/gnu/usr.bin/binutils/gdb/amd64obsd-nat.c
index ccca6c38d5e..0f9b5efac7f 100644
--- a/gnu/usr.bin/binutils/gdb/amd64obsd-nat.c
+++ b/gnu/usr.bin/binutils/gdb/amd64obsd-nat.c
@@ -66,8 +66,8 @@ static int amd64obsd32_r_reg_offset[] =
 
 #include "bsd-kvm.h"
 
-int
-bsd_kvm_supply_pcb (struct regcache *regcache, struct pcb *pcb)
+static int
+amd64obsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 {
   struct switchframe sf;
   int regnum;
@@ -91,22 +91,38 @@ bsd_kvm_supply_pcb (struct regcache *regcache, struct pcb *pcb)
      Together with %rsp in the pcb, this accounts for all callee-saved
      registers specified by the psABI.  From this information we
      reconstruct the register state as it would look when we just
-     returned from cpu_switch().  */
+     returned from cpu_switch().
+
+     For core dumps the pcb is saved by savectx().  In that case the
+     stack frame only contains the return address, and there is no way
+     to recover the other registers.  */
 
   /* The stack pointer shouldn't be zero.  */
   if (pcb->pcb_rsp == 0)
     return 0;
 
+  /* Read the stack frame, and check its validity.  */
   read_memory (pcb->pcb_rsp, (char *) &sf, sizeof sf);
-  pcb->pcb_rsp += sizeof (struct switchframe);
-  regcache_raw_supply (regcache, 12, &sf.sf_r12);
-  regcache_raw_supply (regcache, 13, &sf.sf_r13);
-  regcache_raw_supply (regcache, 14, &sf.sf_r14);
-  regcache_raw_supply (regcache, 15, &sf.sf_r15);
+  if (sf.sf_rbp == pcb->pcb_rbp)
+    {
+      /* Yes, we have a frame that matches cpu_switch().  */
+      pcb->pcb_rsp += sizeof (struct switchframe);
+      regcache_raw_supply (regcache, 12, &sf.sf_r12);
+      regcache_raw_supply (regcache, 13, &sf.sf_r13);
+      regcache_raw_supply (regcache, 14, &sf.sf_r14);
+      regcache_raw_supply (regcache, 15, &sf.sf_r15);
+      regcache_raw_supply (regcache, AMD64_RBX_REGNUM, &sf.sf_rbx);
+      regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &sf.sf_rip);
+    }
+  else
+    {
+      /* No, the pcb must have been last updated by savectx().  */
+      pcb->pcb_rsp += 8;
+      regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &sf);
+    }
+
   regcache_raw_supply (regcache, AMD64_RSP_REGNUM, &pcb->pcb_rsp);
-  regcache_raw_supply (regcache, AMD64_RBP_REGNUM, &sf.sf_rbp);
-  regcache_raw_supply (regcache, AMD64_RBX_REGNUM, &sf.sf_rbx);
-  regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &sf.sf_rip);
+  regcache_raw_supply (regcache, AMD64_RBP_REGNUM, &pcb->pcb_rbp);
 
   return 1;
 }
@@ -121,4 +137,7 @@ _initialize_amd64obsd_nat (void)
   amd64_native_gregset32_reg_offset = amd64obsd32_r_reg_offset;
   amd64_native_gregset32_num_regs = ARRAY_SIZE (amd64obsd32_r_reg_offset);
   amd64_native_gregset64_reg_offset = amd64obsd_r_reg_offset;
+
+  /* Support debugging kernel virtual memory images.  */
+  bsd_kvm_add_target (amd64obsd_supply_pcb);
 }
diff --git a/gnu/usr.bin/binutils/gdb/bsd-kvm.c b/gnu/usr.bin/binutils/gdb/bsd-kvm.c
index b8ef075b831..79ab09505f6 100644
--- a/gnu/usr.bin/binutils/gdb/bsd-kvm.c
+++ b/gnu/usr.bin/binutils/gdb/bsd-kvm.c
@@ -20,9 +20,12 @@
    Boston, MA 02111-1307, USA.  */
 
 #include "defs.h"
+#include "cli/cli-cmds.h"
+#include "command.h"
 #include "frame.h"
 #include "regcache.h"
 #include "target.h"
+#include "value.h"
 
 #include "gdb_assert.h"
 #include <fcntl.h>
@@ -30,6 +33,7 @@
 #include <nlist.h>
 #include "readline/readline.h"
 #include <sys/param.h>
+#include <sys/proc.h>
 #include <sys/user.h>
 
 #include "bsd-kvm.h"
@@ -40,6 +44,10 @@ kvm_t *core_kd;
 /* Address of process control block.  */
 struct pcb *bsd_kvm_paddr;
 
+/* Pointer to architecture-specific function that reconstructs the
+   register state from PCB and supplies it to REGCACHE.  */
+int (*bsd_kvm_supply_pcb)(struct regcache *regcache, struct pcb *pcb);
+
 /* Target ops for libkvm interface.  */
 struct target_ops bsd_kvm_ops;
 
@@ -104,6 +112,8 @@ bsd_kvm_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len,
   return -1;
 }
 
+/* Fetch process control block at address PADDR.  */
+
 static int
 bsd_kvm_fetch_pcb (struct pcb *paddr)
 {
@@ -122,7 +132,10 @@ bsd_kvm_fetch_registers (int regnum)
   struct nlist nl[2];
 
   if (bsd_kvm_paddr)
-    bsd_kvm_fetch_pcb (bsd_kvm_paddr);
+    {
+      bsd_kvm_fetch_pcb (bsd_kvm_paddr);
+      return;
+    }
 
   /* On dumping core, BSD kernels store the faulting context (PCB)
      in the variable "dumppcb".  */
@@ -179,8 +192,8 @@ bsd_kvm_fetch_registers (int regnum)
       struct pcb *paddr;
 
       /* Found thread0.  */
-      nl[1].n_value += offsetof (struct thread, td_pcb);
-      if (kvm_read (core_kd, nl[1].n_value, &paddr, sizeof paddr) == -1)
+      nl[0].n_value += offsetof (struct thread, td_pcb);
+      if (kvm_read (core_kd, nl[0].n_value, &paddr, sizeof paddr) == -1)
 	error ("%s", kvm_geterr (core_kd));
 
       bsd_kvm_fetch_pcb (paddr);
@@ -190,13 +203,77 @@ bsd_kvm_fetch_registers (int regnum)
 
   error ("Cannot find a valid PCB");
 }
+
+
+/* Kernel memory interface commands.  */
+struct cmd_list_element *bsd_kvm_cmdlist;
+
+static void
+bsd_kvm_cmd (char *arg, int fromtty)
+{
+  /* ??? Should this become an alias for "target kvm"?  */
+}
+
+#ifndef HAVE_STRUCT_THREAD_TD_PCB
+
+static void
+bsd_kvm_proc_cmd (char *arg, int fromtty)
+{
+  CORE_ADDR addr;
+
+  if (arg == NULL)
+    error_no_arg ("proc address");
+
+  if (core_kd == NULL)
+    error ("No kernel memory image.");
+
+  addr = parse_and_eval_address (arg);
+  addr += offsetof (struct proc, p_addr);
+
+  if (kvm_read (core_kd, addr, &bsd_kvm_paddr, sizeof bsd_kvm_paddr) == -1)
+    error ("%s", kvm_geterr (core_kd));
+
+  target_fetch_registers (-1);
+
+  flush_cached_frames ();
+  select_frame (get_current_frame ());
+  print_stack_frame (get_selected_frame (), -1, 1);
+}
+
+#endif
+
+static void
+bsd_kvm_pcb_cmd (char *arg, int fromtty)
+{
+  if (arg == NULL)
+    error_no_arg ("pcb address");
+
+  if (core_kd == NULL)
+    error ("No kernel memory image.");
+
+  bsd_kvm_paddr = (struct pcb *) parse_and_eval_address (arg);
+
+  target_fetch_registers (-1);
+
+  flush_cached_frames ();
+  select_frame (get_current_frame ());
+  print_stack_frame (get_selected_frame (), -1, 1);
+}
+
+/* Add the libkvm interface to the list of all possible targets and
+   register CUPPLY_PCB as the architecture-specific process control
+   block interpreter.  */
 
 void
-_initialize_bsd_kvm (void)
+bsd_kvm_add_target (int (*supply_pcb)(struct regcache *, struct pcb *))
 {
+  gdb_assert (bsd_kvm_supply_pcb == NULL);
+  bsd_kvm_supply_pcb = supply_pcb;
+
   bsd_kvm_ops.to_shortname = "kvm";
   bsd_kvm_ops.to_longname = "Kernel memory interface";
-  bsd_kvm_ops.to_doc = "XXX";
+  bsd_kvm_ops.to_doc = "Use a kernel virtual memory image as a target.\n\
+Optionally specify the filename of a core dump.";
   bsd_kvm_ops.to_open = bsd_kvm_open;
   bsd_kvm_ops.to_close = bsd_kvm_close;
   bsd_kvm_ops.to_fetch_registers = bsd_kvm_fetch_registers;
@@ -208,4 +285,15 @@ _initialize_bsd_kvm (void)
   bsd_kvm_ops.to_magic = OPS_MAGIC;
 
   add_target (&bsd_kvm_ops);
+  
+  add_prefix_cmd ("kvm", class_obscure, bsd_kvm_cmd, "\
+Generic command for manipulating the kernel memory interface.",
+		  &bsd_kvm_cmdlist, "kvm ", 0, &cmdlist);
+
+#ifndef HAVE_STRUCT_THREAD_TD_PCB
+  add_cmd ("proc", class_obscure, bsd_kvm_proc_cmd,
+	   "Set current context from proc address", &bsd_kvm_cmdlist);
+#endif
+  add_cmd ("pcb", class_obscure, bsd_kvm_pcb_cmd,
+	   "Set current context from pcb address", &bsd_kvm_cmdlist);
 }
diff --git a/gnu/usr.bin/binutils/gdb/bsd-kvm.h b/gnu/usr.bin/binutils/gdb/bsd-kvm.h
index 129a2f20c72..0660776cf43 100644
--- a/gnu/usr.bin/binutils/gdb/bsd-kvm.h
+++ b/gnu/usr.bin/binutils/gdb/bsd-kvm.h
@@ -25,6 +25,11 @@
 struct pcb;
 struct regcache;
 
-extern int bsd_kvm_supply_pcb (struct regcache *regache, struct pcb *pcb);
+/* Add the libkvm interface to the list of all possible targets and
+   register CUPPLY_PCB as the architecture-specific process control
+   block interpreter.  */
+
+extern void
+  bsd_kvm_add_target (int (*supply_pcb)(struct regcache *, struct pcb *));
 
 #endif /* bsd-kvm.h */
diff --git a/gnu/usr.bin/binutils/gdb/i386nbsd-nat.c b/gnu/usr.bin/binutils/gdb/i386nbsd-nat.c
index 816241e613e..92da7e18dcd 100644
--- a/gnu/usr.bin/binutils/gdb/i386nbsd-nat.c
+++ b/gnu/usr.bin/binutils/gdb/i386nbsd-nat.c
@@ -33,8 +33,8 @@
 
 #include "bsd-kvm.h"
 
-int
-bsd_kvm_supply_pcb (struct regcache *regcache, struct pcb *pcb)
+static int
+i386nbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 {
   struct switchframe sf;
 
@@ -69,3 +69,14 @@ bsd_kvm_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 
   return 1;
 }
+
+
+/* Provide a prototype to silence -Wmissing-prototypes.  */
+void _initialize_i386nbsd_nat (void);
+
+void
+_initialize_i386nbsd_nat (void)
+{
+  /* Support debugging kernel virtual memory images.  */
+  bsd_kvm_add_target (i386nbsd_supply_pcb);
+}
diff --git a/gnu/usr.bin/binutils/gdb/m68kbsd-nat.c b/gnu/usr.bin/binutils/gdb/m68kbsd-nat.c
index 8954a164189..285c149428d 100644
--- a/gnu/usr.bin/binutils/gdb/m68kbsd-nat.c
+++ b/gnu/usr.bin/binutils/gdb/m68kbsd-nat.c
@@ -81,7 +81,7 @@ m68kbsd_collect_gregset (const struct regcache *regcache,
   for (i = M68K_D0_REGNUM; i <= M68K_PC_REGNUM; i++)
     {
       if (regnum == -1 || regnum == i)
-	regcache_raw_collect (regcache, regnum, regs + i * 4);
+	regcache_raw_collect (regcache, i, regs + i * 4);
     }
 }
 
@@ -98,8 +98,7 @@ m68kbsd_collect_fpregset (struct regcache *regcache,
   for (i = M68K_FP0_REGNUM; i <= M68K_FPI_REGNUM; i++)
     {
       if (regnum == -1 || regnum == i)
-	regcache_raw_collect (regcache, regnum,
-			      regs + m68kbsd_fpreg_offset (i));
+	regcache_raw_collect (regcache, i, regs + m68kbsd_fpreg_offset (i));
     }
 }
 
@@ -186,8 +185,8 @@ store_inferior_registers (int regnum)
 #define PCB_REGS_SP 11
 #endif
 
-int
-bsd_kvm_supply_pcb (struct regcache *regcache, struct pcb *pcb)
+static int
+m68kbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 {
   int regnum, tmp;
   int i = 0;
@@ -216,3 +215,14 @@ bsd_kvm_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 
   return 1;
 }
+
+
+/* Provide a prototype to silence -Wmissing-prototypes.  */
+void _initialize_m68kbsd_nat (void);
+
+void
+_initialize_m68kbsd_nat (void)
+{
+  /* Support debugging kernel virtual memory images.  */
+  bsd_kvm_add_target (m68kbsd_supply_pcb);
+}
diff --git a/gnu/usr.bin/binutils/gdb/sparcnbsd-nat.c b/gnu/usr.bin/binutils/gdb/sparcnbsd-nat.c
index 88941712439..01089eeef32 100644
--- a/gnu/usr.bin/binutils/gdb/sparcnbsd-nat.c
+++ b/gnu/usr.bin/binutils/gdb/sparcnbsd-nat.c
@@ -33,8 +33,8 @@
 
 #include "bsd-kvm.h"
 
-int
-bsd_kvm_supply_pcb (struct regcache *regcache, struct pcb *pcb)
+static int
+sparc32nbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 {
   /* The following is true for NetBSD 1.6.2:
 
@@ -65,4 +65,7 @@ void
 _initialize_sparcnbsd_nat (void)
 {
   sparc_gregset = &sparc32nbsd_gregset;
+
+  /* Support debugging kernel virtual memory images.  */
+  bsd_kvm_add_target (sparc32nbsd_supply_pcb);
 }