* frv-linux-tdep.c (frv_linux_sigcontext_reg_addr): Update comments.

	Adjust incorrectly computed constant for realtime signal frame.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index ba05a3a..c2634a5 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2005-03-18  Kevin Buettner  <kevinb@redhat.com>
+
+       * frv-linux-tdep.c (frv_linux_sigcontext_reg_addr): Update comments.
+       Adjust incorrectly computed constant for realtime signal frame.
+
 2005-03-18  Mark Kettenis  <kettenis@elgar.sibelius.xs4all.nl>
 
        From Ralf Corsepius <ralf.corsepius@rtems.org>

diff --git a/gdb/frv-linux-tdep.c b/gdb/frv-linux-tdep.c
index e78fe39..11d4dbc 100644 (file)
--- a/gdb/frv-linux-tdep.c
+++ b/gdb/frv-linux-tdep.c
@@ -67,14 +67,14 @@ frv_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
   return retval;
 }
 
-/* Given NEXT_FRAME, "callee" frame of the sigtramp frame that we
+/* Given NEXT_FRAME, the "callee" frame of the sigtramp frame that we
    wish to decode, and REGNO, one of the frv register numbers defined
    in frv-tdep.h, return the address of the saved register (corresponding
    to REGNO) in the sigtramp frame.  Return -1 if the register is not
    found in the sigtramp frame.  The magic numbers in the code below
    were computed by examining the following kernel structs:
 
-   From arch/frvnommu/signal.c:
+   From arch/frv/kernel/signal.c:
 
       struct sigframe
       {
@@ -96,7 +96,7 @@ frv_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
              uint32_t retcode[2];
       };
 
-   From include/asm-frvnommu/ucontext.h:
+   From include/asm-frv/ucontext.h:
 
       struct ucontext {
              unsigned long             uc_flags;
@@ -106,14 +106,22 @@ frv_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
              sigset_t          uc_sigmask;
       };
 
-   From include/asm-frvnommu/sigcontext.h:
+   From include/asm-frv/signal.h:
+
+      typedef struct sigaltstack {
+             void *ss_sp;
+             int ss_flags;
+             size_t ss_size;
+      } stack_t;
+
+   From include/asm-frv/sigcontext.h:
 
       struct sigcontext {
              struct user_context       sc_context;
              unsigned long             sc_oldmask;
       } __attribute__((aligned(8)));
 
-   From include/asm-frvnommu/registers.h:
+   From include/asm-frv/registers.h:
       struct user_int_regs
       {
              unsigned long             psr;
@@ -184,15 +192,19 @@ frv_linux_sigcontext_reg_addr (struct frame_info *next_frame, int regno,
       else if (tramp_type == RT_SIGTRAMP)
        {
          /* For a realtime sigtramp frame, SP + 12 contains a pointer
-            to the a ucontext struct.  The ucontext struct contains
-            a sigcontext struct starting 12 bytes in.  */
+            to the a ucontext struct.  The ucontext struct contains a
+            sigcontext struct starting 24 bytes in.  (The offset of
+            uc_mcontext within struct ucontext is derived as follows: 
+            stack_t is a 12-byte struct and struct sigcontext is
+            8-byte aligned.  This gives an offset of 8 + 12 + 4 (for
+            padding) = 24.) */
          if (target_read_memory (sp + 12, buf, sizeof buf) != 0)
            {
              warning (_("Can't read realtime sigtramp frame."));
              return 0;
            }
          sc_addr = extract_unsigned_integer (buf, sizeof buf);
-         sc_addr += 12;
+         sc_addr += 24;
        }
       else
        internal_error (__FILE__, __LINE__, _("not a signal trampoline"));