gdb/doc/

[binutils-gdb.git] / gdb / mips-linux-tdep.c

diff --git a/gdb/mips-linux-tdep.c b/gdb/mips-linux-tdep.c
index d4137f4749af177f7e58c5fcb2e09a6b27962dc3..5924b30984db3d95f2219f18082da3c3b1de7c98 100644 (file)
--- a/gdb/mips-linux-tdep.c
+++ b/gdb/mips-linux-tdep.c
@@ -1,6 +1,6 @@
 /* Target-dependent code for GNU/Linux on MIPS processors.
 
 /* Target-dependent code for GNU/Linux on MIPS processors.
 

-   Copyright (C) 2001, 2002, 2004, 2005, 2006, 2007
+   Copyright (C) 2001, 2002, 2004, 2005, 2006, 2007, 2008, 2009, 2010

    Free Software Foundation, Inc.
 
    This file is part of GDB.
    Free Software Foundation, Inc.
 
    This file is part of GDB.


@@ -37,6 +37,7 @@
 #include "symtab.h"
 #include "target-descriptions.h"
 #include "mips-linux-tdep.h"
 #include "symtab.h"
 #include "target-descriptions.h"
 #include "mips-linux-tdep.h"

+#include "glibc-tdep.h"

 
 static struct target_so_ops mips_svr4_so_ops;
 
 
 static struct target_so_ops mips_svr4_so_ops;
 


@@ -54,6 +55,7 @@ mips_linux_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
 {
   CORE_ADDR jb_addr;
   struct gdbarch *gdbarch = get_frame_arch (frame);
 {
   CORE_ADDR jb_addr;
   struct gdbarch *gdbarch = get_frame_arch (frame);

+  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);

   char buf[gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT];
 
   jb_addr = get_frame_register_unsigned (frame, MIPS_A0_REGNUM);
   char buf[gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT];
 
   jb_addr = get_frame_register_unsigned (frame, MIPS_A0_REGNUM);


@@ -64,7 +66,8 @@ mips_linux_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
     return 0;
 
   *pc = extract_unsigned_integer (buf,
     return 0;
 
   *pc = extract_unsigned_integer (buf,

-                                 gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT);
+                                 gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT,
+                                 byte_order);

 
   return 1;
 }
 
   return 1;
 }


@@ -76,10 +79,11 @@ mips_linux_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
 static void
 supply_32bit_reg (struct regcache *regcache, int regnum, const void *addr)
 {
 static void
 supply_32bit_reg (struct regcache *regcache, int regnum, const void *addr)
 {

+  struct gdbarch *gdbarch = get_regcache_arch (regcache);
+  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);

   gdb_byte buf[MAX_REGISTER_SIZE];
   gdb_byte buf[MAX_REGISTER_SIZE];

-  store_signed_integer (buf,
-                       register_size (get_regcache_arch (regcache), regnum),
-                        extract_signed_integer (addr, 4));
+  store_signed_integer (buf, register_size (gdbarch, regnum), byte_order,
+                        extract_signed_integer (addr, 4, byte_order));

   regcache_raw_supply (regcache, regnum, buf);
 }
 
   regcache_raw_supply (regcache, regnum, buf);
 }
 


@@ -257,6 +261,7 @@ mips64_linux_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
 {
   CORE_ADDR jb_addr;
   struct gdbarch *gdbarch = get_frame_arch (frame);
 {
   CORE_ADDR jb_addr;
   struct gdbarch *gdbarch = get_frame_arch (frame);

+  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);

   void *buf = alloca (gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT);
   int element_size = gdbarch_ptr_bit (gdbarch) == 32 ? 4 : 8;
 
   void *buf = alloca (gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT);
   int element_size = gdbarch_ptr_bit (gdbarch) == 32 ? 4 : 8;
 


@@ -268,7 +273,8 @@ mips64_linux_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
     return 0;
 
   *pc = extract_unsigned_integer (buf,
     return 0;
 
   *pc = extract_unsigned_integer (buf,

-                                 gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT);
+                                 gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT,
+                                 byte_order);

 
   return 1;
 }
 
   return 1;
 }


@@ -279,7 +285,7 @@ mips64_linux_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
 
 /* Supply a 64-bit register.  */
 
 
 /* Supply a 64-bit register.  */
 

-void
+static void

 supply_64bit_reg (struct regcache *regcache, int regnum,
                  const gdb_byte *buf)
 {
 supply_64bit_reg (struct regcache *regcache, int regnum,
                  const gdb_byte *buf)
 {


@@ -342,9 +348,10 @@ mips64_fill_gregset (const struct regcache *regcache,
                     mips64_elf_gregset_t *gregsetp, int regno)
 {
   struct gdbarch *gdbarch = get_regcache_arch (regcache);
                     mips64_elf_gregset_t *gregsetp, int regno)
 {
   struct gdbarch *gdbarch = get_regcache_arch (regcache);

+  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);

   int regaddr, regi;
   mips64_elf_greg_t *regp = *gregsetp;
   int regaddr, regi;
   mips64_elf_greg_t *regp = *gregsetp;

-  void *src, *dst;
+  void *dst;

 
   if (regno == -1)
     {
 
   if (regno == -1)
     {


@@ -387,9 +394,10 @@ mips64_fill_gregset (const struct regcache *regcache,
       LONGEST val;
 
       regcache_raw_collect (regcache, regno, buf);
       LONGEST val;
 
       regcache_raw_collect (regcache, regno, buf);

-      val = extract_signed_integer (buf, register_size (gdbarch, regno));
+      val = extract_signed_integer (buf, register_size (gdbarch, regno),
+                                   byte_order);

       dst = regp + regaddr;
       dst = regp + regaddr;

-      store_signed_integer (dst, 8, val);
+      store_signed_integer (dst, 8, byte_order, val);

     }
 }
 
     }
 }
 


@@ -439,6 +447,7 @@ mips64_fill_fpregset (const struct regcache *regcache,
                      mips64_elf_fpregset_t *fpregsetp, int regno)
 {
   struct gdbarch *gdbarch = get_regcache_arch (regcache);
                      mips64_elf_fpregset_t *fpregsetp, int regno)
 {
   struct gdbarch *gdbarch = get_regcache_arch (regcache);

+  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);

   gdb_byte *to;
 
   if ((regno >= gdbarch_fp0_regnum (gdbarch))
   gdb_byte *to;
 
   if ((regno >= gdbarch_fp0_regnum (gdbarch))


@@ -467,9 +476,10 @@ mips64_fill_fpregset (const struct regcache *regcache,
       LONGEST val;
 
       regcache_raw_collect (regcache, regno, buf);
       LONGEST val;
 
       regcache_raw_collect (regcache, regno, buf);

-      val = extract_signed_integer (buf, register_size (gdbarch, regno));
+      val = extract_signed_integer (buf, register_size (gdbarch, regno),
+                                   byte_order);

       to = (gdb_byte *) (*fpregsetp + 32);
       to = (gdb_byte *) (*fpregsetp + 32);

-      store_signed_integer (to, 4, val);
+      store_signed_integer (to, 4, byte_order, val);

     }
   else if (regno == mips_regnum (gdbarch)->fp_implementation_revision)
     {
     }
   else if (regno == mips_regnum (gdbarch)->fp_implementation_revision)
     {


@@ -477,9 +487,10 @@ mips64_fill_fpregset (const struct regcache *regcache,
       LONGEST val;
 
       regcache_raw_collect (regcache, regno, buf);
       LONGEST val;
 
       regcache_raw_collect (regcache, regno, buf);

-      val = extract_signed_integer (buf, register_size (gdbarch, regno));
+      val = extract_signed_integer (buf, register_size (gdbarch, regno),
+                                   byte_order);

       to = (gdb_byte *) (*fpregsetp + 32) + 4;
       to = (gdb_byte *) (*fpregsetp + 32) + 4;

-      store_signed_integer (to, 4, val);
+      store_signed_integer (to, 4, byte_order, val);

     }
   else if (regno == -1)
     {
     }
   else if (regno == -1)
     {


@@ -603,7 +614,8 @@ mips_linux_in_dynsym_stub (CORE_ADDR pc, char *name)
 {
   unsigned char buf[28], *p;
   ULONGEST insn, insn1;
 {
   unsigned char buf[28], *p;
   ULONGEST insn, insn1;

-  int n64 = (mips_abi (current_gdbarch) == MIPS_ABI_N64);
+  int n64 = (mips_abi (target_gdbarch) == MIPS_ABI_N64);
+  enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);

 
   read_memory (pc - 12, buf, 28);
 
 
   read_memory (pc - 12, buf, 28);
 


@@ -621,7 +633,7 @@ mips_linux_in_dynsym_stub (CORE_ADDR pc, char *name)
   p = buf + 12;
   while (p >= buf)
     {
   p = buf + 12;
   while (p >= buf)
     {

-      insn = extract_unsigned_integer (p, 4);
+      insn = extract_unsigned_integer (p, 4, byte_order);

       if (insn == insn1)
        break;
       p -= 4;
       if (insn == insn1)
        break;
       p -= 4;


@@ -629,7 +641,7 @@ mips_linux_in_dynsym_stub (CORE_ADDR pc, char *name)
   if (p < buf)
     return 0;
 
   if (p < buf)
     return 0;
 

-  insn = extract_unsigned_integer (p + 4, 4);
+  insn = extract_unsigned_integer (p + 4, 4, byte_order);

   if (n64)
     {
       /* daddu t7,ra */
   if (n64)
     {
       /* daddu t7,ra */


@@ -643,12 +655,12 @@ mips_linux_in_dynsym_stub (CORE_ADDR pc, char *name)
        return 0;
     }
 
        return 0;
     }
 

-  insn = extract_unsigned_integer (p + 8, 4);
+  insn = extract_unsigned_integer (p + 8, 4, byte_order);

   /* jalr t9,ra */
   if (insn != 0x0320f809)
     return 0;
 
   /* jalr t9,ra */
   if (insn != 0x0320f809)
     return 0;
 

-  insn = extract_unsigned_integer (p + 12, 4);
+  insn = extract_unsigned_integer (p + 12, 4, byte_order);

   if (n64)
     {
       /* daddiu t8,zero,0 */
   if (n64)
     {
       /* daddiu t8,zero,0 */


@@ -666,13 +678,13 @@ mips_linux_in_dynsym_stub (CORE_ADDR pc, char *name)
 }
 
 /* Return non-zero iff PC belongs to the dynamic linker resolution
 }
 
 /* Return non-zero iff PC belongs to the dynamic linker resolution

-   code or to a stub.  */
+   code, a PLT entry, or a lazy binding stub.  */

 
 static int
 mips_linux_in_dynsym_resolve_code (CORE_ADDR pc)
 {
   /* Check whether PC is in the dynamic linker.  This also checks
 
 static int
 mips_linux_in_dynsym_resolve_code (CORE_ADDR pc)
 {
   /* Check whether PC is in the dynamic linker.  This also checks

-     whether it is in the .plt section, which MIPS does not use.  */
+     whether it is in the .plt section, used by non-PIC executables.  */

   if (svr4_in_dynsym_resolve_code (pc))
     return 1;
 
   if (svr4_in_dynsym_resolve_code (pc))
     return 1;
 


@@ -688,8 +700,8 @@ mips_linux_in_dynsym_resolve_code (CORE_ADDR pc)
    and glibc_skip_solib_resolver in glibc-tdep.c.  The normal glibc
    implementation of this triggers at "fixup" from the same objfile as
    "_dl_runtime_resolve"; MIPS GNU/Linux can trigger at
    and glibc_skip_solib_resolver in glibc-tdep.c.  The normal glibc
    implementation of this triggers at "fixup" from the same objfile as
    "_dl_runtime_resolve"; MIPS GNU/Linux can trigger at

-   "__dl_runtime_resolve" directly.  An unresolved PLT entry will
-   point to _dl_runtime_resolve, which will first call
+   "__dl_runtime_resolve" directly.  An unresolved lazy binding
+   stub will point to _dl_runtime_resolve, which will first call

    __dl_runtime_resolve, and then pass control to the resolved
    function.  */
 
    __dl_runtime_resolve, and then pass control to the resolved
    function.  */
 


@@ -701,9 +713,9 @@ mips_linux_skip_resolver (struct gdbarch *gdbarch, CORE_ADDR pc)
   resolver = lookup_minimal_symbol ("__dl_runtime_resolve", NULL, NULL);
 
   if (resolver && SYMBOL_VALUE_ADDRESS (resolver) == pc)
   resolver = lookup_minimal_symbol ("__dl_runtime_resolve", NULL, NULL);
 
   if (resolver && SYMBOL_VALUE_ADDRESS (resolver) == pc)

-    return frame_pc_unwind (get_current_frame ());
+    return frame_unwind_caller_pc (get_current_frame ());

 
 

-  return 0;
+  return glibc_skip_solib_resolver (gdbarch, pc);

 }
 
 /* Signal trampoline support.  There are four supported layouts for a
 }
 
 /* Signal trampoline support.  There are four supported layouts for a


@@ -712,12 +724,12 @@ mips_linux_skip_resolver (struct gdbarch *gdbarch, CORE_ADDR pc)
    efficient way, but simplest.  First, declare all the unwinders.  */
 
 static void mips_linux_o32_sigframe_init (const struct tramp_frame *self,
    efficient way, but simplest.  First, declare all the unwinders.  */
 
 static void mips_linux_o32_sigframe_init (const struct tramp_frame *self,

-                                         struct frame_info *next_frame,
+                                         struct frame_info *this_frame,

                                          struct trad_frame_cache *this_cache,
                                          CORE_ADDR func);
 
 static void mips_linux_n32n64_sigframe_init (const struct tramp_frame *self,
                                          struct trad_frame_cache *this_cache,
                                          CORE_ADDR func);
 
 static void mips_linux_n32n64_sigframe_init (const struct tramp_frame *self,

-                                            struct frame_info *next_frame,
+                                            struct frame_info *this_frame,

                                             struct trad_frame_cache *this_cache,
                                             CORE_ADDR func);
 
                                             struct trad_frame_cache *this_cache,
                                             CORE_ADDR func);
 


@@ -785,7 +797,7 @@ static const struct tramp_frame mips_linux_n64_rt_sigframe = {
 
    struct sigframe {
      u32 sf_ass[4];            [argument save space for o32]
 
    struct sigframe {
      u32 sf_ass[4];            [argument save space for o32]

-     u32 sf_code[2];           [signal trampoline]
+     u32 sf_code[2];           [signal trampoline or fill]

      struct sigcontext sf_sc;
      sigset_t sf_mask;
    };
      struct sigcontext sf_sc;
      sigset_t sf_mask;
    };


@@ -815,7 +827,7 @@ static const struct tramp_frame mips_linux_n64_rt_sigframe = {
 
    struct rt_sigframe {
      u32 rs_ass[4];            [argument save space for o32]
 
    struct rt_sigframe {
      u32 rs_ass[4];            [argument save space for o32]

-     u32 rs_code[2]            [signal trampoline]
+     u32 rs_code[2]            [signal trampoline or fill]

      struct siginfo rs_info;
      struct ucontext rs_uc;
    };
      struct siginfo rs_info;
      struct ucontext rs_uc;
    };


@@ -830,7 +842,6 @@ static const struct tramp_frame mips_linux_n64_rt_sigframe = {
    };  */
 /* *INDENT-ON* */
 
    };  */
 /* *INDENT-ON* */
 

-#define SIGFRAME_CODE_OFFSET         (4 * 4)

 #define SIGFRAME_SIGCONTEXT_OFFSET   (6 * 4)
 
 #define RTSIGFRAME_SIGINFO_SIZE      128
 #define SIGFRAME_SIGCONTEXT_OFFSET   (6 * 4)
 
 #define RTSIGFRAME_SIGINFO_SIZE      128


@@ -853,20 +864,21 @@ static const struct tramp_frame mips_linux_n64_rt_sigframe = {
 
 static void
 mips_linux_o32_sigframe_init (const struct tramp_frame *self,
 
 static void
 mips_linux_o32_sigframe_init (const struct tramp_frame *self,

-                             struct frame_info *next_frame,
+                             struct frame_info *this_frame,

                              struct trad_frame_cache *this_cache,
                              CORE_ADDR func)
 {
                              struct trad_frame_cache *this_cache,
                              CORE_ADDR func)
 {

-  struct gdbarch *gdbarch = get_frame_arch (next_frame);
+  struct gdbarch *gdbarch = get_frame_arch (this_frame);

   int ireg, reg_position;
   int ireg, reg_position;

-  CORE_ADDR sigcontext_base = func - SIGFRAME_CODE_OFFSET;
+  CORE_ADDR frame_sp = get_frame_sp (this_frame);
+  CORE_ADDR sigcontext_base;

   const struct mips_regnum *regs = mips_regnum (gdbarch);
   CORE_ADDR regs_base;
 
   if (self == &mips_linux_o32_sigframe)
   const struct mips_regnum *regs = mips_regnum (gdbarch);
   CORE_ADDR regs_base;
 
   if (self == &mips_linux_o32_sigframe)

-    sigcontext_base += SIGFRAME_SIGCONTEXT_OFFSET;
+    sigcontext_base = frame_sp + SIGFRAME_SIGCONTEXT_OFFSET;

   else
   else

-    sigcontext_base += RTSIGFRAME_SIGCONTEXT_OFFSET;
+    sigcontext_base = frame_sp + RTSIGFRAME_SIGCONTEXT_OFFSET;

 
   /* I'm not proud of this hack.  Eventually we will have the
      infrastructure to indicate the size of saved registers on a
 
   /* I'm not proud of this hack.  Eventually we will have the
      infrastructure to indicate the size of saved registers on a


@@ -935,9 +947,7 @@ mips_linux_o32_sigframe_init (const struct tramp_frame *self,
                           sigcontext_base + SIGCONTEXT_BADVADDR);
 
   /* Choice of the bottom of the sigframe is somewhat arbitrary.  */
                           sigcontext_base + SIGCONTEXT_BADVADDR);
 
   /* Choice of the bottom of the sigframe is somewhat arbitrary.  */

-  trad_frame_set_id (this_cache,
-                    frame_id_build (func - SIGFRAME_CODE_OFFSET,
-                                    func));
+  trad_frame_set_id (this_cache, frame_id_build (frame_sp, func));

 }
 
 /* *INDENT-OFF* */
 }
 
 /* *INDENT-OFF* */


@@ -945,7 +955,7 @@ mips_linux_o32_sigframe_init (const struct tramp_frame *self,
 
   struct rt_sigframe_n32 {
     u32 rs_ass[4];                  [ argument save space for o32 ]
 
   struct rt_sigframe_n32 {
     u32 rs_ass[4];                  [ argument save space for o32 ]

-    u32 rs_code[2];                 [ signal trampoline ]
+    u32 rs_code[2];                 [ signal trampoline or fill ]

     struct siginfo rs_info;
     struct ucontextn32 rs_uc;
   };
     struct siginfo rs_info;
     struct ucontextn32 rs_uc;
   };


@@ -958,7 +968,7 @@ mips_linux_o32_sigframe_init (const struct tramp_frame *self,
     sigset_t            uc_sigmask;   [ mask last for extensibility ]
   };
 
     sigset_t            uc_sigmask;   [ mask last for extensibility ]
   };
 

-  struct rt_sigframe_n32 {
+  struct rt_sigframe {

     u32 rs_ass[4];                  [ argument save space for o32 ]
     u32 rs_code[2];                 [ signal trampoline ]
     struct siginfo rs_info;
     u32 rs_ass[4];                  [ argument save space for o32 ]
     u32 rs_code[2];                 [ signal trampoline ]
     struct siginfo rs_info;


@@ -979,15 +989,23 @@ mips_linux_o32_sigframe_init (const struct tramp_frame *self,
     unsigned long long sc_regs[32];
     unsigned long long sc_fpregs[32];
     unsigned long long sc_mdhi;
     unsigned long long sc_regs[32];
     unsigned long long sc_fpregs[32];
     unsigned long long sc_mdhi;

+    unsigned long long sc_hi1;
+    unsigned long long sc_hi2;
+    unsigned long long sc_hi3;

     unsigned long long sc_mdlo;
     unsigned long long sc_mdlo;

+    unsigned long long sc_lo1;
+    unsigned long long sc_lo2;
+    unsigned long long sc_lo3;

     unsigned long long sc_pc;
     unsigned long long sc_pc;

-    unsigned int       sc_status;

     unsigned int       sc_fpc_csr;
     unsigned int       sc_fpc_csr;

-    unsigned int       sc_fpc_eir;

     unsigned int       sc_used_math;
     unsigned int       sc_used_math;

-    unsigned int       sc_cause;
-    unsigned int       sc_badvaddr;
-  };  */
+    unsigned int       sc_dsp;
+    unsigned int       sc_reserved;
+  };
+
+  That is the post-2.6.12 definition of the 64-bit sigcontext; before
+  then, there were no hi1-hi3 or lo1-lo3.  Cause and badvaddr were
+  included too.  */

 /* *INDENT-ON* */
 
 #define N32_STACK_T_SIZE               STACK_T_SIZE
 /* *INDENT-ON* */
 
 #define N32_STACK_T_SIZE               STACK_T_SIZE


@@ -1004,30 +1022,28 @@ mips_linux_o32_sigframe_init (const struct tramp_frame *self,
 #define N64_SIGCONTEXT_REGS     (0 * 8)
 #define N64_SIGCONTEXT_FPREGS   (32 * 8)
 #define N64_SIGCONTEXT_HI       (64 * 8)
 #define N64_SIGCONTEXT_REGS     (0 * 8)
 #define N64_SIGCONTEXT_FPREGS   (32 * 8)
 #define N64_SIGCONTEXT_HI       (64 * 8)

-#define N64_SIGCONTEXT_LO       (65 * 8)
-#define N64_SIGCONTEXT_PC       (66 * 8)
-#define N64_SIGCONTEXT_FPCSR    (67 * 8 + 1 * 4)
-#define N64_SIGCONTEXT_FIR      (67 * 8 + 2 * 4)
-#define N64_SIGCONTEXT_CAUSE    (67 * 8 + 4 * 4)
-#define N64_SIGCONTEXT_BADVADDR (67 * 8 + 5 * 4)
+#define N64_SIGCONTEXT_LO       (68 * 8)
+#define N64_SIGCONTEXT_PC       (72 * 8)
+#define N64_SIGCONTEXT_FPCSR    (73 * 8)

 
 #define N64_SIGCONTEXT_REG_SIZE 8
 
 static void
 mips_linux_n32n64_sigframe_init (const struct tramp_frame *self,
 
 #define N64_SIGCONTEXT_REG_SIZE 8
 
 static void
 mips_linux_n32n64_sigframe_init (const struct tramp_frame *self,

-                                struct frame_info *next_frame,
+                                struct frame_info *this_frame,

                                 struct trad_frame_cache *this_cache,
                                 CORE_ADDR func)
 {
                                 struct trad_frame_cache *this_cache,
                                 CORE_ADDR func)
 {

-  struct gdbarch *gdbarch = get_frame_arch (next_frame);
+  struct gdbarch *gdbarch = get_frame_arch (this_frame);

   int ireg, reg_position;
   int ireg, reg_position;

-  CORE_ADDR sigcontext_base = func - SIGFRAME_CODE_OFFSET;
+  CORE_ADDR frame_sp = get_frame_sp (this_frame);
+  CORE_ADDR sigcontext_base;

   const struct mips_regnum *regs = mips_regnum (gdbarch);
 
   if (self == &mips_linux_n32_rt_sigframe)
   const struct mips_regnum *regs = mips_regnum (gdbarch);
 
   if (self == &mips_linux_n32_rt_sigframe)

-    sigcontext_base += N32_SIGFRAME_SIGCONTEXT_OFFSET;
+    sigcontext_base = frame_sp + N32_SIGFRAME_SIGCONTEXT_OFFSET;

   else
   else

-    sigcontext_base += N64_SIGFRAME_SIGCONTEXT_OFFSET;
+    sigcontext_base = frame_sp + N64_SIGFRAME_SIGCONTEXT_OFFSET;

 
   if (mips_linux_restart_reg_p (gdbarch))
     trad_frame_set_reg_addr (this_cache,
 
   if (mips_linux_restart_reg_p (gdbarch))
     trad_frame_set_reg_addr (this_cache,


@@ -1063,17 +1079,9 @@ mips_linux_n32n64_sigframe_init (const struct tramp_frame *self,
   trad_frame_set_reg_addr (this_cache,
                           regs->lo + gdbarch_num_regs (gdbarch),
                           sigcontext_base + N64_SIGCONTEXT_LO);
   trad_frame_set_reg_addr (this_cache,
                           regs->lo + gdbarch_num_regs (gdbarch),
                           sigcontext_base + N64_SIGCONTEXT_LO);

-  trad_frame_set_reg_addr (this_cache,
-                          regs->cause + gdbarch_num_regs (gdbarch),
-                          sigcontext_base + N64_SIGCONTEXT_CAUSE);
-  trad_frame_set_reg_addr (this_cache,
-                          regs->badvaddr + gdbarch_num_regs (gdbarch),
-                          sigcontext_base + N64_SIGCONTEXT_BADVADDR);

 
   /* Choice of the bottom of the sigframe is somewhat arbitrary.  */
 
   /* Choice of the bottom of the sigframe is somewhat arbitrary.  */

-  trad_frame_set_id (this_cache,
-                    frame_id_build (func - SIGFRAME_CODE_OFFSET,
-                                    func));
+  trad_frame_set_id (this_cache, frame_id_build (frame_sp, func));

 }
 
 static void
 }
 
 static void


@@ -1102,6 +1110,26 @@ mips_linux_restart_reg_p (struct gdbarch *gdbarch)
   return register_size (gdbarch, MIPS_RESTART_REGNUM) > 0;
 }
 
   return register_size (gdbarch, MIPS_RESTART_REGNUM) > 0;
 }
 

+/* When FRAME is at a syscall instruction, return the PC of the next
+   instruction to be executed.  */
+
+static CORE_ADDR
+mips_linux_syscall_next_pc (struct frame_info *frame)
+{
+  CORE_ADDR pc = get_frame_pc (frame);
+  ULONGEST v0 = get_frame_register_unsigned (frame, MIPS_V0_REGNUM);
+
+  /* If we are about to make a sigreturn syscall, use the unwinder to
+     decode the signal frame.  */
+  if (v0 == MIPS_NR_sigreturn
+      || v0 == MIPS_NR_rt_sigreturn
+      || v0 == MIPS_NR_N64_rt_sigreturn
+      || v0 == MIPS_NR_N32_rt_sigreturn)
+    return frame_unwind_caller_pc (get_current_frame ());
+
+  return pc + 4;
+}
+

 /* Initialize one of the GNU/Linux OS ABIs.  */
 
 static void
 /* Initialize one of the GNU/Linux OS ABIs.  */
 
 static void


@@ -1149,11 +1177,9 @@ mips_linux_init_abi (struct gdbarch_info info,
        tramp_frame_prepend_unwinder (gdbarch, &mips_linux_n64_rt_sigframe);
        break;
       default:
        tramp_frame_prepend_unwinder (gdbarch, &mips_linux_n64_rt_sigframe);
        break;
       default:

-       internal_error (__FILE__, __LINE__, _("can't handle ABI"));

        break;
     }
 
        break;
     }
 

-  set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);

   set_gdbarch_skip_solib_resolver (gdbarch, mips_linux_skip_resolver);
 
   set_gdbarch_software_single_step (gdbarch, mips_software_single_step);
   set_gdbarch_skip_solib_resolver (gdbarch, mips_linux_skip_resolver);
 
   set_gdbarch_software_single_step (gdbarch, mips_software_single_step);


@@ -1177,6 +1203,8 @@ mips_linux_init_abi (struct gdbarch_info info,
   set_gdbarch_core_read_description (gdbarch,
                                     mips_linux_core_read_description);
 
   set_gdbarch_core_read_description (gdbarch,
                                     mips_linux_core_read_description);
 

+  tdep->syscall_next_pc = mips_linux_syscall_next_pc;
+

   if (tdesc_data)
     {
       const struct tdesc_feature *feature;
   if (tdesc_data)
     {
       const struct tdesc_feature *feature;


@@ -1196,6 +1224,9 @@ mips_linux_init_abi (struct gdbarch_info info,
     }
 }
 
     }
 }
 

+/* Provide a prototype to silence -Wmissing-prototypes.  */
+extern initialize_file_ftype _initialize_mips_linux_tdep;
+

 void
 _initialize_mips_linux_tdep (void)
 {
 void
 _initialize_mips_linux_tdep (void)
 {