[v4] Implement "info proc mappings" for NetBSD

Message ID 20200411234507.17070-1-n54@gmx.com
State Superseded
Headers show
Series
  • [v4] Implement "info proc mappings" for NetBSD
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Commit Message

Kamil Rytarowski April 11, 2020, 11:45 p.m.
Define nbsd_nat_target::find_memory_regions and
nbsd_nat_target::info_proc. info_proc handles as of now only
the "mappings" command.

Define a local static function kinfo_get_vmmap() that reads
the process memory layout of a specified process.
kinfo_get_vmmap() wraps the sysctl(3) call.

nbsd-tdep.c defines now utility functions for printing the
process memory layout:
 * nbsd_info_proc_mappings_header()
 * nbsd_vm_map_entry_flags()
 * nbsd_info_proc_mappings_entry()

gdb/ChangeLog:

	* nbsd-nat.c; Include "nbsd-tdep.h", "inferior.h" and "gdbarch.h".
	* nbsd-nat.c (nbsd_nat_target::find_memory_regions)
	(nbsd_nat_target::info_proc): New functions.
	* nbsd-nat.c (kinfo_get_vmmap): New function.
	* nbsd-nat.c (nbsd_nat_target::info_proc) Use
	nbsd_info_proc_mappings_header and nbsd_info_proc_mappings_entry.
	* nbsd-tdep.c (nbsd_info_proc_mappings_header)
	(nbsd_info_proc_mappings_entry, nbsd_vm_map_entry_flags): New
	functions.
	* nbsd-tdep.c (KINFO_VME_PROT_READ, KINFO_VME_PROT_WRITE)
	(KINFO_VME_PROT_EXEC, KINFO_VME_FLAG_COW)
	(KINFO_VME_FLAG_NEEDS_COPY, KINFO_VME_FLAG_NOCOREDUMP)
	(KINFO_VME_FLAG_PAGEABLE, KINFO_VME_FLAG_GROWS_UP)
	(KINFO_VME_FLAG_GROWS_DOWN): New.
---
 gdb/ChangeLog   |  17 ++++++
 gdb/nbsd-nat.c  | 150 ++++++++++++++++++++++++++++++++++++++++++++++++
 gdb/nbsd-nat.h  |   2 +
 gdb/nbsd-tdep.c |  91 +++++++++++++++++++++++++++++
 gdb/nbsd-tdep.h |  18 ++++++
 5 files changed, 278 insertions(+)

--
2.25.0

Comments

Simon Marchi April 11, 2020, 11:49 p.m. | #1
On 2020-04-11 7:45 p.m., Kamil Rytarowski wrote:
> Define nbsd_nat_target::find_memory_regions and

> nbsd_nat_target::info_proc. info_proc handles as of now only

> the "mappings" command.

> 

> Define a local static function kinfo_get_vmmap() that reads

> the process memory layout of a specified process.

> kinfo_get_vmmap() wraps the sysctl(3) call.

> 

> nbsd-tdep.c defines now utility functions for printing the

> process memory layout:

>  * nbsd_info_proc_mappings_header()

>  * nbsd_vm_map_entry_flags()

>  * nbsd_info_proc_mappings_entry()


When sending a new version, can you please rebase it on the current master?

The patch does not apply cleanly on master today, so it doesn't really reflect what's
going to be merged.

Simon
Kamil Rytarowski April 12, 2020, 12:09 a.m. | #2
On 12.04.2020 01:49, Simon Marchi wrote:
> On 2020-04-11 7:45 p.m., Kamil Rytarowski wrote:

>> Define nbsd_nat_target::find_memory_regions and

>> nbsd_nat_target::info_proc. info_proc handles as of now only

>> the "mappings" command.

>>

>> Define a local static function kinfo_get_vmmap() that reads

>> the process memory layout of a specified process.

>> kinfo_get_vmmap() wraps the sysctl(3) call.

>>

>> nbsd-tdep.c defines now utility functions for printing the

>> process memory layout:

>>  * nbsd_info_proc_mappings_header()

>>  * nbsd_vm_map_entry_flags()

>>  * nbsd_info_proc_mappings_entry()

>

> When sending a new version, can you please rebase it on the current master?

>

> The patch does not apply cleanly on master today, so it doesn't really reflect what's

> going to be merged.

>

> Simon

>


Rebased in v5.

Patch

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 650b74bae4a..b12965e41bb 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,20 @@ 
+2020-03-20  Kamil Rytarowski  <n54@gmx.com>
+
+	* nbsd-nat.c; Include "nbsd-tdep.h", "inferior.h" and "gdbarch.h".
+	* nbsd-nat.c (nbsd_nat_target::find_memory_regions)
+	(nbsd_nat_target::info_proc): New functions.
+	* nbsd-nat.c (kinfo_get_vmmap): New function.
+	* nbsd-nat.c (nbsd_nat_target::info_proc) Use
+	nbsd_info_proc_mappings_header and nbsd_info_proc_mappings_entry.
+	* nbsd-tdep.c (nbsd_info_proc_mappings_header)
+	(nbsd_info_proc_mappings_entry, nbsd_vm_map_entry_flags): New
+	functions.
+	* nbsd-tdep.c (KINFO_VME_PROT_READ, KINFO_VME_PROT_WRITE)
+	(KINFO_VME_PROT_EXEC, KINFO_VME_FLAG_COW)
+	(KINFO_VME_FLAG_NEEDS_COPY, KINFO_VME_FLAG_NOCOREDUMP)
+	(KINFO_VME_FLAG_PAGEABLE, KINFO_VME_FLAG_GROWS_UP)
+	(KINFO_VME_FLAG_GROWS_DOWN): New.
+
 2020-03-20  Kamil Rytarowski  <n54@gmx.com>

 	* amd64-bsd-nat.c (gdb_ptrace): Change return type from `int' to
diff --git a/gdb/nbsd-nat.c b/gdb/nbsd-nat.c
index 326bbe3aec3..1651f2033e3 100644
--- a/gdb/nbsd-nat.c
+++ b/gdb/nbsd-nat.c
@@ -20,6 +20,9 @@ 
 #include "defs.h"

 #include "nbsd-nat.h"
+#include "nbsd-tdep.h"
+#include "inferior.h"
+#include "gdbarch.h"

 #include <sys/types.h>
 #include <sys/ptrace.h>
@@ -39,3 +42,150 @@  nbsd_nat_target::pid_to_exec_file (int pid)
     return NULL;
   return buf;
 }
+
+/* Retrieve all the memory regions in the specified process.  */
+
+static gdb::unique_xmalloc_ptr<struct kinfo_vmentry[]>
+nbsd_kinfo_get_vmmap (pid_t pid, size_t *size)
+{
+  int mib[5] = {CTL_VM, VM_PROC, VM_PROC_MAP, pid,
+		sizeof (struct kinfo_vmentry)};
+
+  size_t length = 0;
+  if (sysctl (mib, ARRAY_SIZE (mib), NULL, &length, NULL, 0))
+    {
+      *size = 0;
+      return NULL;
+    }
+
+  /* Prereserve more space.  The length argument is volatile and can change
+     between the sysctl(3) calls as this function can be called against a
+     running process.  */
+  length = length * 5 / 3;
+
+  gdb::unique_xmalloc_ptr<struct kinfo_vmentry[]> kiv
+    (XNEWVAR (kinfo_vmentry, length));
+
+  if (sysctl (mib, ARRAY_SIZE (mib), kiv.get (), &length, NULL, 0))
+    {
+      *size = 0;
+      return NULL;
+    }
+
+  *size = length / sizeof (struct kinfo_vmentry);
+  return kiv;
+}
+
+/* Iterate over all the memory regions in the current inferior,
+   calling FUNC for each memory region.  OBFD is passed as the last
+   argument to FUNC.  */
+
+int
+nbsd_nat_target::find_memory_regions (find_memory_region_ftype func,
+				      void *data)
+{
+  pid_t pid = inferior_ptid.pid ();
+
+  size_t nitems;
+  gdb::unique_xmalloc_ptr<struct kinfo_vmentry[]> vmentl
+    = nbsd_kinfo_get_vmmap (pid, &nitems);
+  if (vmentl == NULL)
+    perror_with_name (_("Couldn't fetch VM map entries."));
+
+  for (size_t i = 0; i < nitems; i++)
+    {
+      struct kinfo_vmentry *kve = &vmentl[i];
+
+      /* Skip unreadable segments and those where MAP_NOCORE has been set.  */
+      if (!(kve->kve_protection & KVME_PROT_READ)
+	  || kve->kve_flags & KVME_FLAG_NOCOREDUMP)
+	continue;
+
+      /* Skip segments with an invalid type.  */
+      switch (kve->kve_type)
+	{
+	case KVME_TYPE_VNODE:
+	case KVME_TYPE_ANON:
+	case KVME_TYPE_SUBMAP:
+	case KVME_TYPE_OBJECT:
+	  break;
+	default:
+	  continue;
+	}
+
+      size_t size = kve->kve_end - kve->kve_start;
+      if (info_verbose)
+	{
+	  fprintf_filtered (gdb_stdout,
+			    "Save segment, %ld bytes at %s (%c%c%c)\n",
+			    (long) size,
+			    paddress (target_gdbarch (), kve->kve_start),
+			    kve->kve_protection & KVME_PROT_READ ? 'r' : '-',
+			    kve->kve_protection & KVME_PROT_WRITE ? 'w' : '-',
+			    kve->kve_protection & KVME_PROT_EXEC ? 'x' : '-');
+	}
+
+      /* Invoke the callback function to create the corefile segment.
+	 Pass MODIFIED as true, we do not know the real modification state.  */
+      func (kve->kve_start, size, kve->kve_protection & KVME_PROT_READ,
+	    kve->kve_protection & KVME_PROT_WRITE,
+	    kve->kve_protection & KVME_PROT_EXEC, 1, data);
+    }
+  return 0;
+}
+
+/* Implement the "info_proc" target_ops method.  */
+
+bool
+nbsd_nat_target::info_proc (const char *args, enum info_proc_what what)
+{
+  pid_t pid;
+  bool do_mappings = false;
+
+  switch (what)
+    {
+    case IP_MAPPINGS:
+      do_mappings = true;
+      break;
+    default:
+      error (_("Not supported on this target."));
+    }
+
+  gdb_argv built_argv (args);
+  if (built_argv.count () == 0)
+    {
+      pid = inferior_ptid.pid ();
+      if (pid == 0)
+        error (_("No current process: you must name one."));
+    }
+  else if (built_argv.count () == 1 && isdigit (built_argv[0][0]))
+    pid = strtol (built_argv[0], NULL, 10);
+  else
+    error (_("Invalid arguments."));
+
+  printf_filtered (_("process %d\n"), pid);
+
+  if (do_mappings)
+    {
+      size_t nvment;
+      gdb::unique_xmalloc_ptr<struct kinfo_vmentry[]> vmentl
+	= nbsd_kinfo_get_vmmap (pid, &nvment);
+
+      if (vmentl != nullptr)
+	{
+	  int addr_bit = TARGET_CHAR_BIT * sizeof (void *);
+	  nbsd_info_proc_mappings_header (addr_bit);
+
+	  struct kinfo_vmentry *kve = vmentl.get ();
+	  for (int i = 0; i < nvment; i++, kve++)
+	    nbsd_info_proc_mappings_entry (addr_bit, kve->kve_start,
+					   kve->kve_end, kve->kve_offset,
+					   kve->kve_flags, kve->kve_protection,
+					   kve->kve_path);
+	}
+      else
+	warning (_("unable to fetch virtual memory map"));
+    }
+
+  return true;
+}
diff --git a/gdb/nbsd-nat.h b/gdb/nbsd-nat.h
index a752fbe572d..98af21d0bda 100644
--- a/gdb/nbsd-nat.h
+++ b/gdb/nbsd-nat.h
@@ -27,6 +27,8 @@ 
 struct nbsd_nat_target : public inf_ptrace_target
 {
   char *pid_to_exec_file (int pid) override;
+  int find_memory_regions (find_memory_region_ftype func, void *data) override;
+  bool info_proc (const char *, enum info_proc_what) override;
 };

 #endif /* nbsd-nat.h */
diff --git a/gdb/nbsd-tdep.c b/gdb/nbsd-tdep.c
index 49bb2b706bd..4f24b62a8a7 100644
--- a/gdb/nbsd-tdep.c
+++ b/gdb/nbsd-tdep.c
@@ -23,6 +23,23 @@ 
 #include "solib-svr4.h"
 #include "nbsd-tdep.h"

+/* Flags in the 'kve_protection' field in struct kinfo_vmentry.  These
+   match the KVME_PROT_* constants in <sys/sysctl.h>.  */
+
+#define	KINFO_VME_PROT_READ	0x00000001
+#define	KINFO_VME_PROT_WRITE	0x00000002
+#define	KINFO_VME_PROT_EXEC	0x00000004
+
+/* Flags in the 'kve_flags' field in struct kinfo_vmentry.  These
+   match the KVME_FLAG_* constants in <sys/sysctl.h>.  */
+
+#define	KINFO_VME_FLAG_COW		0x00000001
+#define	KINFO_VME_FLAG_NEEDS_COPY	0x00000002
+#define	KINFO_VME_FLAG_NOCOREDUMP	0x00000004
+#define	KINFO_VME_FLAG_PAGEABLE		0x00000008
+#define	KINFO_VME_FLAG_GROWS_UP		0x00000010
+#define	KINFO_VME_FLAG_GROWS_DOWN	0x00000020
+
 /* FIXME: kettenis/20060115: We should really eliminate the next two
    functions completely.  */

@@ -47,3 +64,77 @@  nbsd_pc_in_sigtramp (CORE_ADDR pc, const char *func_name)
   return (func_name != NULL
 	  && startswith (func_name, "__sigtramp"));
 }
+
+/* See nbsd-tdep.h.  */
+
+void
+nbsd_info_proc_mappings_header (int addr_bit)
+{
+  printf_filtered (_("Mapped address spaces:\n\n"));
+  if (addr_bit == 64)
+    {
+      printf_filtered ("  %18s %18s %10s %10s %9s %s\n",
+		       "Start Addr",
+		       "  End Addr",
+		       "      Size", "    Offset", "Flags  ", "File");
+    }
+  else
+    {
+      printf_filtered ("\t%10s %10s %10s %10s %9s %s\n",
+		       "Start Addr",
+		       "  End Addr",
+		       "      Size", "    Offset", "Flags  ", "File");
+    }
+}
+
+/* Helper function to generate mappings flags for a single VM map
+   entry in 'info proc mappings'.  */
+
+static const char *
+nbsd_vm_map_entry_flags (int kve_flags, int kve_protection)
+{
+  static char vm_flags[9];
+
+  vm_flags[0] = (kve_protection & KINFO_VME_PROT_READ) ? 'r' : '-';
+  vm_flags[1] = (kve_protection & KINFO_VME_PROT_WRITE) ? 'w' : '-';
+  vm_flags[2] = (kve_protection & KINFO_VME_PROT_EXEC) ? 'x' : '-';
+  vm_flags[3] = ' ';
+  vm_flags[4] = (kve_flags & KINFO_VME_FLAG_COW) ? 'C' : '-';
+  vm_flags[5] = (kve_flags & KINFO_VME_FLAG_NEEDS_COPY) ? 'N' : '-';
+  vm_flags[6] = (kve_flags & KINFO_VME_FLAG_PAGEABLE) ? 'P' : '-';
+  vm_flags[7] = (kve_flags & KINFO_VME_FLAG_GROWS_UP) ? 'U'
+    : (kve_flags & KINFO_VME_FLAG_GROWS_DOWN) ? 'D' : '-';
+  vm_flags[8] = '\0';
+
+  return vm_flags;
+}
+
+/* See nbsd-tdep.h.  */
+
+void
+nbsd_info_proc_mappings_entry (int addr_bit, ULONGEST kve_start,
+			       ULONGEST kve_end, ULONGEST kve_offset,
+			       int kve_flags, int kve_protection,
+			       const char *kve_path)
+{
+  if (addr_bit == 64)
+    {
+      printf_filtered ("  %18s %18s %10s %10s %9s %s\n",
+		       hex_string (kve_start),
+		       hex_string (kve_end),
+		       hex_string (kve_end - kve_start),
+		       hex_string (kve_offset),
+		       nbsd_vm_map_entry_flags (kve_flags, kve_protection),
+		       kve_path);
+    }
+  else
+    {
+      printf_filtered ("\t%10s %10s %10s %10s %9s %s\n",
+		       hex_string (kve_start),
+		       hex_string (kve_end),
+		       hex_string (kve_end - kve_start),
+		       hex_string (kve_offset),
+		       nbsd_vm_map_entry_flags (kve_flags, kve_protection),
+		       kve_path);
+    }
+}
diff --git a/gdb/nbsd-tdep.h b/gdb/nbsd-tdep.h
index c99a8b537b6..581ffb4455a 100644
--- a/gdb/nbsd-tdep.h
+++ b/gdb/nbsd-tdep.h
@@ -25,4 +25,22 @@  struct link_map_offsets *nbsd_lp64_solib_svr4_fetch_link_map_offsets (void);

 int nbsd_pc_in_sigtramp (CORE_ADDR, const char *);

+/* Output the header for "info proc mappings".  ADDR_BIT is the size
+   of a virtual address in bits.  */
+
+extern void nbsd_info_proc_mappings_header (int addr_bit);
+
+/* Output description of a single memory range for "info proc
+   mappings".  ADDR_BIT is the size of a virtual address in bits.  The
+   KVE_START, KVE_END, KVE_OFFSET, KVE_FLAGS, and KVE_PROTECTION
+   parameters should contain the value of the corresponding fields in
+   a 'struct kinfo_vmentry'.  The KVE_PATH parameter should contain a
+   pointer to the 'kve_path' field in a 'struct kinfo_vmentry'. */
+
+extern void nbsd_info_proc_mappings_entry (int addr_bit, ULONGEST kve_start,
+					   ULONGEST kve_end,
+					   ULONGEST kve_offset,
+					   int kve_flags, int kve_protection,
+					   const char *kve_path);
+
 #endif /* NBSD_TDEP_H */