2005-07-11 Jeff Johnston <jjohnstn@redhat.com>
* ia64-tdep.c (pseudo_regs): Add CURSOR_ADDR_REGNUM.
(ia64_register_names): Add empty string for CURSOR_ADDR_REGNUM.
(ia64_frame_prev_register): Default a request for CURSOR_ADDR_REGNUM
to return 0.
(ia64_sigtramp_frame_prev_register): Ditto.
(ia64_gdb2uw_regnum): Map CURSOR_ADDR_REGNUM to INT_MAX so
it won't clash with any legitimate UNW register number.
(ia64_unwind_cursor): New callback.
(ia64_libunwind_descr): Add new ia64_unwind_cursor callback.
* libunwind-frame.h (struct libunwind_descr): Add new slot
for unwind cursor callback.
* libunwind-frame.c (libunwind_frame_cache): Attempt to copy
and step previous cursor if possible, otherwise, create new
cursor.
(libunwind_frame_prev_register): Support request for
getting the cursor address.
--- gdb-6.3/gdb/ia64-tdep.c.fix 2005-07-11 18:13:42.000000000 -0400
+++ gdb-6.3/gdb/ia64-tdep.c 2005-07-11 18:15:52.000000000 -0400
@@ -141,7 +141,7 @@ static int lr_regnum = IA64_VRAP_REGNUM;
they may not be accessible via the ptrace register get/set interfaces. */
enum pseudo_regs { FIRST_PSEUDO_REGNUM = NUM_IA64_RAW_REGS, VBOF_REGNUM = IA64_NAT127_REGNUM + 1, V32_REGNUM,
V127_REGNUM = V32_REGNUM + 95,
- VP0_REGNUM, VP16_REGNUM = VP0_REGNUM + 16, VP63_REGNUM = VP0_REGNUM + 63, LAST_PSEUDO_REGNUM };
+ VP0_REGNUM, VP16_REGNUM = VP0_REGNUM + 16, VP63_REGNUM = VP0_REGNUM + 63, CURSOR_ADDR_REGNUM, LAST_PSEUDO_REGNUM };
/* Array of register names; There should be ia64_num_regs strings in
the initializer. */
@@ -253,6 +253,7 @@ static char *ia64_register_names[] =
"p40", "p41", "p42", "p43", "p44", "p45", "p46", "p47",
"p48", "p49", "p50", "p51", "p52", "p53", "p54", "p55",
"p56", "p57", "p58", "p59", "p60", "p61", "p62", "p63",
+ ""
};
struct ia64_frame_cache
@@ -1855,6 +1856,12 @@ ia64_frame_prev_register (struct frame_i
read_memory (addr, valuep, register_size (current_gdbarch, regnum));
}
}
+ else if (regnum == CURSOR_ADDR_REGNUM)
+ {
+ /* The cursor is the address of the ia64 libunwind cursor.
+ Default to 0. */
+ *lvalp = lval_memory;
+ }
else
{
CORE_ADDR addr = 0;
@@ -2177,6 +2184,12 @@ ia64_sigtramp_frame_prev_register (struc
*addrp = pr_addr;
}
}
+ else if (regnum == CURSOR_ADDR_REGNUM)
+ {
+ /* The cursor is the address of the ia64 libunwind cursor.
+ Default to 0. */
+ *lvalp = lval_memory;
+ }
else
{
/* All other registers not listed above. */
@@ -2296,6 +2309,8 @@ ia64_gdb2uw_regnum (int regnum)
return UNW_IA64_AR + (regnum - IA64_AR0_REGNUM);
else if ((unsigned) (regnum - IA64_NAT0_REGNUM) < 128)
return UNW_IA64_NAT + (regnum - IA64_NAT0_REGNUM);
+ else if (regnum == CURSOR_ADDR_REGNUM)
+ return INT_MAX;
else
return -1;
}
@@ -2331,6 +2346,21 @@ ia64_uw2gdb_regnum (int uw_regnum)
return -1;
}
+/* Special callback function to allow libunwind-frame to get
+ the address of the next frame's cursor so it may be copied and
+ stepped. */
+static unw_cursor_t *
+ia64_unwind_cursor (struct frame_info *next_frame)
+{
+ unw_cursor_t *cursor_addr;
+ char buf[8];
+
+ frame_unwind_register (next_frame, CURSOR_ADDR_REGNUM, buf);
+ cursor_addr = (unw_cursor_t *)extract_unsigned_integer (buf, 8);
+
+ return cursor_addr;
+}
+
/* Gdb libunwind-frame callback function to reveal if register is a float
register or not. */
static int
@@ -3111,6 +3141,7 @@ static struct libunwind_descr ia64_libun
ia64_gdb2uw_regnum,
ia64_uw2gdb_regnum,
ia64_is_fpreg,
+ ia64_unwind_cursor,
&ia64_unw_accessors,
&ia64_unw_rse_accessors,
};
--- gdb-6.3/gdb/libunwind-frame.c.fix 2005-07-11 18:17:05.000000000 -0400
+++ gdb-6.3/gdb/libunwind-frame.c 2005-07-11 18:20:31.000000000 -0400
@@ -122,6 +122,7 @@ libunwind_frame_set_descr (struct gdbarc
arch_descr->is_fpreg = descr->is_fpreg;
arch_descr->accessors = descr->accessors;
arch_descr->special_accessors = descr->special_accessors;
+ arch_descr->unwind_cursor = descr->unwind_cursor;
}
static struct libunwind_frame_cache *
@@ -129,6 +130,7 @@ libunwind_frame_cache (struct frame_info
{
unw_accessors_t *acc;
unw_addr_space_t as;
+ unw_cursor_t *cursor_addr;
unw_word_t fp;
unw_regnum_t uw_sp_regnum;
struct libunwind_frame_cache *cache;
@@ -147,22 +149,33 @@ libunwind_frame_cache (struct frame_info
&& get_frame_type (next_frame) != SIGTRAMP_FRAME)
return NULL;
- /* Get a libunwind cursor to the previous frame. We do this by initializing
- a cursor. Libunwind treats a new cursor as the top of stack and will get
- the current register set via the libunwind register accessor. Now, we
- provide the platform-specific accessors and we set up the register accessor to use
- the frame register unwinding interfaces so that we properly get the registers for
- the current frame rather than the top. We then use the unw_step function to
- move the libunwind cursor back one frame. We can later use this cursor to find previous
- registers via the unw_get_reg interface which will invoke libunwind's special logic. */
+ /* Get a libunwind cursor to the previous frame. We do this by getting
+ the address of the next frame's cursor (if one exists). If we are at
+ the top of stack, then we will get back a zero cursor address and we
+ should initialize a new cursor.
+
+ Otherwise, we copy the cursor address contents and step back by one.
+ Libunwind will use our register accessors which are set up to
+ unwind registers from the previous frame. We will later use this cursor
+ to find previous registers via the unw_get_reg interface. By passing
+ back a cursor, we allow libunwind to handle sigaltstack which requires
+ one cursor stepped back for all frames. */
descr = libunwind_descr (get_frame_arch (next_frame));
- acc = descr->accessors;
- as = unw_create_addr_space_p (acc,
+ cursor_addr = descr->unwind_cursor (next_frame);
+
+ if (cursor_addr == 0)
+ {
+ acc = descr->accessors;
+ as = unw_create_addr_space_p (acc,
TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
? __BIG_ENDIAN
: __LITTLE_ENDIAN);
- unw_init_remote_p (&cache->cursor, as, next_frame);
+ unw_init_remote_p (&cache->cursor, as, next_frame);
+ }
+ else /* make copy */
+ cache->cursor = *cursor_addr;
+
if (unw_step_p (&cache->cursor) < 0)
return NULL;
@@ -285,6 +298,16 @@ libunwind_frame_prev_register (struct fr
if (uw_regnum < 0)
return;
+ /* Check if we are unwinding the cursor address which just gives
+ back the address of the next frame's cursor. This is a special
+ modification to support unwinding through a sigaltstack. */
+ if (uw_regnum == INT_MAX)
+ {
+ store_unsigned_integer (valuep, sizeof (CORE_ADDR),
+ (CORE_ADDR)&cache->cursor);
+ return;
+ }
+
/* To get the previous register, we use the libunwind register APIs with
the cursor we have already pushed back to the previous frame. */
--- gdb-6.3/gdb/libunwind-frame.h.fix 2005-07-11 18:17:24.000000000 -0400
+++ gdb-6.3/gdb/libunwind-frame.h 2005-07-11 18:18:46.000000000 -0400
@@ -37,6 +37,7 @@ struct libunwind_descr
int (*gdb2uw) (int);
int (*uw2gdb) (int);
int (*is_fpreg) (int);
+ unw_cursor_t *(*unwind_cursor) (struct frame_info *next_frame);
void *accessors;
void *special_accessors;
};