Linux: Access memory even if threads are running

[deliverable/binutils-gdb.git] / gdb / sparc-nat.c

diff --git a/gdb/sparc-nat.c b/gdb/sparc-nat.c
index 9b7691337713286d5fc1cb8c7cefc93100d53ac6..7f09a60420db28626c051ee583923514a24d6079 100644 (file)
--- a/gdb/sparc-nat.c
+++ b/gdb/sparc-nat.c
@@ -1,6 +1,6 @@
 /* Native-dependent code for SPARC.
 
-   Copyright (C) 2003-2019 Free Software Foundation, Inc.
+   Copyright (C) 2003-2021 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
@@ -78,6 +78,19 @@ typedef struct fp_status fpregset_t;
 #define PTRACE_SETFPREGS PT_SETFPREGS
 #endif
 
+static PTRACE_TYPE_RET
+gdb_ptrace (PTRACE_TYPE_ARG1 request, ptid_t ptid, PTRACE_TYPE_ARG3 addr)
+{
+#ifdef __NetBSD__
+  /* Support for NetBSD threads: unlike other ptrace implementations in this
+     file, NetBSD requires that we pass both the pid and lwp.  */
+  return ptrace (request, ptid.pid (), addr, ptid.lwp ());
+#else
+  pid_t pid = get_ptrace_pid (ptid);
+  return ptrace (request, pid, addr, 0);
+#endif
+}
+
 /* Register set description.  */
 const struct sparc_gregmap *sparc_gregmap;
 const struct sparc_fpregmap *sparc_fpregmap;
@@ -134,25 +147,11 @@ sparc32_fpregset_supplies_p (struct gdbarch *gdbarch, int regnum)
    for all registers (including the floating-point registers).  */
 
 void
-sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)
+sparc_fetch_inferior_registers (process_stratum_target *proc_target,
+                               regcache *regcache, int regnum)
 {
   struct gdbarch *gdbarch = regcache->arch ();
-  pid_t pid;
-
-  /* NOTE: cagney/2002-12-03: This code assumes that the currently
-     selected light weight processes' registers can be written
-     directly into the selected thread's register cache.  This works
-     fine when given an 1:1 LWP:thread model (such as found on
-     GNU/Linux) but will, likely, have problems when used on an N:1
-     (userland threads) or N:M (userland multiple LWP) model.  In the
-     case of the latter two, the LWP's registers do not necessarily
-     belong to the selected thread (the LWP could be in the middle of
-     executing the thread switch code).
-
-     These functions should instead be parameterized with an explicit
-     object (struct regcache, struct thread_info?) into which the LWPs
-     registers can be written.  */
-  pid = get_ptrace_pid (regcache->ptid ());
+  ptid_t ptid = regcache->ptid ();
 
   if (regnum == SPARC_G0_REGNUM)
     {
@@ -166,9 +165,14 @@ sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)
     {
       gregset_t regs;
 
-      if (ptrace (PTRACE_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
+      if (gdb_ptrace (PTRACE_GETREGS, ptid, (PTRACE_TYPE_ARG3) &regs) == -1)
        perror_with_name (_("Couldn't get registers"));
 
+      /* Deep down, sparc_supply_rwindow reads memory, so needs the global
+        thread context to be set.  */
+      scoped_restore restore_inferior_ptid
+       = make_scoped_restore (&inferior_ptid, ptid);
+
       sparc_supply_gregset (sparc_gregmap, regcache, -1, &regs);
       if (regnum != -1)
        return;
@@ -178,7 +182,7 @@ sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)
     {
       fpregset_t fpregs;
 
-      if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
+      if (gdb_ptrace (PTRACE_GETFPREGS, ptid, (PTRACE_TYPE_ARG3) &fpregs) == -1)
        perror_with_name (_("Couldn't get floating point status"));
 
       sparc_supply_fpregset (sparc_fpregmap, regcache, -1, &fpregs);
@@ -186,25 +190,22 @@ sparc_fetch_inferior_registers (struct regcache *regcache, int regnum)
 }
 
 void
-sparc_store_inferior_registers (struct regcache *regcache, int regnum)
+sparc_store_inferior_registers (process_stratum_target *proc_target,
+                               regcache *regcache, int regnum)
 {
   struct gdbarch *gdbarch = regcache->arch ();
-  pid_t pid;
-
-  /* NOTE: cagney/2002-12-02: See comment in fetch_inferior_registers
-     about threaded assumptions.  */
-  pid = get_ptrace_pid (regcache->ptid ());
+  ptid_t ptid = regcache->ptid ();
 
   if (regnum == -1 || sparc_gregset_supplies_p (gdbarch, regnum))
     {
       gregset_t regs;
 
-      if (ptrace (PTRACE_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
+      if (gdb_ptrace (PTRACE_GETREGS, ptid, (PTRACE_TYPE_ARG3) &regs) == -1)
        perror_with_name (_("Couldn't get registers"));
 
       sparc_collect_gregset (sparc_gregmap, regcache, regnum, &regs);
 
-      if (ptrace (PTRACE_SETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
+      if (gdb_ptrace (PTRACE_SETREGS, ptid, (PTRACE_TYPE_ARG3) &regs) == -1)
        perror_with_name (_("Couldn't write registers"));
 
       /* Deal with the stack regs.  */
@@ -214,6 +215,12 @@ sparc_store_inferior_registers (struct regcache *regcache, int regnum)
          ULONGEST sp;
 
          regcache_cooked_read_unsigned (regcache, SPARC_SP_REGNUM, &sp);
+
+         /* Deep down, sparc_collect_rwindow writes memory, so needs the global
+            thread context to be set.  */
+         scoped_restore restore_inferior_ptid
+           = make_scoped_restore (&inferior_ptid, ptid);
+
          sparc_collect_rwindow (regcache, sp, regnum);
        }
 
@@ -225,7 +232,7 @@ sparc_store_inferior_registers (struct regcache *regcache, int regnum)
     {
       fpregset_t fpregs, saved_fpregs;
 
-      if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
+      if (gdb_ptrace (PTRACE_GETFPREGS, ptid, (PTRACE_TYPE_ARG3) &fpregs) == -1)
        perror_with_name (_("Couldn't get floating-point registers"));
 
       memcpy (&saved_fpregs, &fpregs, sizeof (fpregs));
@@ -237,8 +244,8 @@ sparc_store_inferior_registers (struct regcache *regcache, int regnum)
         to write the registers if nothing changed.  */
       if (memcmp (&saved_fpregs, &fpregs, sizeof (fpregs)) != 0)
        {
-         if (ptrace (PTRACE_SETFPREGS, pid,
-                     (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
+         if (gdb_ptrace (PTRACE_SETFPREGS, ptid,
+                         (PTRACE_TYPE_ARG3) &fpregs) == -1)
            perror_with_name (_("Couldn't write floating-point registers"));
        }
 
@@ -305,8 +312,9 @@ sparc_xfer_wcookie (enum target_object object,
 }
 \f
 
+void _initialize_sparc_nat ();
 void
-_initialize_sparc_nat (void)
+_initialize_sparc_nat ()
 {
   /* Default to using SunOS 4 register sets.  */
   if (sparc_gregmap == NULL)