/* Target-dependent code for the IA-64 for GDB, the GNU debugger.
Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
- 2009 Free Software Foundation, Inc.
+ 2009, 2010 Free Software Foundation, Inc.
This file is part of GDB.
SLOTNUM (`adress & 0x0f', value in the range <0..2>). We need to know
SLOTNUM in ia64_memory_remove_breakpoint.
+ There is one special case where we need to be extra careful:
+ L-X instructions, which are instructions that occupy 2 slots
+ (The L part is always in slot 1, and the X part is always in
+ slot 2). We must refuse to insert breakpoints for an address
+ that points at slot 2 of a bundle where an L-X instruction is
+ present, since there is logically no instruction at that address.
+ However, to make things more interesting, the opcode of L-X
+ instructions is located in slot 2. This means that, to insert
+ a breakpoint at an address that points to slot 1, we actually
+ need to write the breakpoint in slot 2! Slot 1 is actually
+ the extended operand, so writing the breakpoint there would not
+ have the desired effect. Another side-effect of this issue
+ is that we need to make sure that the shadow contents buffer
+ does save byte 15 of our instruction bundle (this is the tail
+ end of slot 2, which wouldn't be saved if we were to insert
+ the breakpoint in slot 1).
+
ia64 16-byte bundle layout:
| 5 bits | slot 0 with 41 bits | slot 1 with 41 bits | slot 2 with 41 bits |
The current addressing used by the code below:
original PC placed_address placed_size required covered
== bp_tgt->shadow_len reqd \subset covered
- 0xABCDE0 0xABCDE0 0xE <0x0...0x5> <0x0..0xD>
- 0xABCDE1 0xABCDE1 0xE <0x5...0xA> <0x1..0xE>
+ 0xABCDE0 0xABCDE0 0x10 <0x0...0x5> <0x0..0xF>
+ 0xABCDE1 0xABCDE1 0xF <0x5...0xA> <0x1..0xF>
0xABCDE2 0xABCDE2 0xE <0xA...0xF> <0x2..0xF>
-
+
+ L-X instructions are treated a little specially, as explained above:
+ 0xABCDE1 0xABCDE1 0xF <0xA...0xF> <0x1..0xF>
+
`objdump -d' and some other tools show a bit unjustified offsets:
original PC byte where starts the instruction objdump offset
0xABCDE0 0xABCDE0 0xABCDE0
{
CORE_ADDR addr = bp_tgt->placed_address;
gdb_byte bundle[BUNDLE_LEN];
- int slotnum = (int) (addr & 0x0f) / SLOT_MULTIPLIER;
+ int slotnum = (int) (addr & 0x0f) / SLOT_MULTIPLIER, shadow_slotnum;
long long instr_breakpoint;
int val;
int template;
addr &= ~0x0f;
- /* Disable the automatic memory restoration from breakpoints while
- we read our instruction bundle. Otherwise, the general restoration
- mechanism kicks in and we would possibly remove parts of the adjacent
+ /* Enable the automatic memory restoration from breakpoints while
+ we read our instruction bundle for the purpose of SHADOW_CONTENTS.
+ Otherwise, we could possibly store into the shadow parts of the adjacent
placed breakpoints. It is due to our SHADOW_CONTENTS overlapping the real
breakpoint instruction bits region. */
- cleanup = make_show_memory_breakpoints_cleanup (1);
+ cleanup = make_show_memory_breakpoints_cleanup (0);
val = target_read_memory (addr, bundle, BUNDLE_LEN);
+ if (val != 0)
+ {
+ do_cleanups (cleanup);
+ return val;
+ }
- /* Check for L type instruction in slot 1, if present then bump up the slot
- number to the slot 2. */
- template = extract_bit_field (bundle, 0, 5);
- if (slotnum == 1 && template_encoding_table[template][slotnum] == L)
- slotnum = 2;
+ /* SHADOW_SLOTNUM saves the original slot number as expected by the caller
+ for addressing the SHADOW_CONTENTS placement. */
+ shadow_slotnum = slotnum;
+
+ /* Always cover the last byte of the bundle in case we are inserting
+ a breakpoint on an L-X instruction. */
+ bp_tgt->shadow_len = BUNDLE_LEN - shadow_slotnum;
- /* Slot number 2 may skip at most 2 bytes at the beginning. */
- bp_tgt->placed_size = bp_tgt->shadow_len = BUNDLE_LEN - 2;
+ template = extract_bit_field (bundle, 0, 5);
+ if (template_encoding_table[template][slotnum] == X)
+ {
+ /* X unit types can only be used in slot 2, and are actually
+ part of a 2-slot L-X instruction. We cannot break at this
+ address, as this is the second half of an instruction that
+ lives in slot 1 of that bundle. */
+ gdb_assert (slotnum == 2);
+ error (_("Can't insert breakpoint for non-existing slot X"));
+ }
+ if (template_encoding_table[template][slotnum] == L)
+ {
+ /* L unit types can only be used in slot 1. But the associated
+ opcode for that instruction is in slot 2, so bump the slot number
+ accordingly. */
+ gdb_assert (slotnum == 1);
+ slotnum = 2;
+ }
/* Store the whole bundle, except for the initial skipped bytes by the slot
number interpreted as bytes offset in PLACED_ADDRESS. */
- memcpy (bp_tgt->shadow_contents, bundle + slotnum, bp_tgt->shadow_len);
+ memcpy (bp_tgt->shadow_contents, bundle + shadow_slotnum, bp_tgt->shadow_len);
+
+ /* Re-read the same bundle as above except that, this time, read it in order
+ to compute the new bundle inside which we will be inserting the
+ breakpoint. Therefore, disable the automatic memory restoration from
+ breakpoints while we read our instruction bundle. Otherwise, the general
+ restoration mechanism kicks in and we would possibly remove parts of the
+ adjacent placed breakpoints. It is due to our SHADOW_CONTENTS overlapping
+ the real breakpoint instruction bits region. */
+ make_show_memory_breakpoints_cleanup (1);
+ val = target_read_memory (addr, bundle, BUNDLE_LEN);
+ if (val != 0)
+ {
+ do_cleanups (cleanup);
+ return val;
+ }
/* Breakpoints already present in the code will get deteacted and not get
reinserted by bp_loc_is_permanent. Multiple breakpoints at the same
paddress (gdbarch, bp_tgt->placed_address));
replace_slotN_contents (bundle, IA64_BREAKPOINT, slotnum);
- if (val == 0)
- val = target_write_memory (addr + slotnum, bundle + slotnum,
- bp_tgt->shadow_len);
+ bp_tgt->placed_size = bp_tgt->shadow_len;
+
+ val = target_write_memory (addr + shadow_slotnum, bundle + shadow_slotnum,
+ bp_tgt->shadow_len);
do_cleanups (cleanup);
return val;
{
CORE_ADDR addr = bp_tgt->placed_address;
gdb_byte bundle_mem[BUNDLE_LEN], bundle_saved[BUNDLE_LEN];
- int slotnum = (addr & 0x0f) / SLOT_MULTIPLIER;
+ int slotnum = (addr & 0x0f) / SLOT_MULTIPLIER, shadow_slotnum;
long long instr_breakpoint, instr_saved;
int val;
int template;
breakpoint instruction bits region. */
cleanup = make_show_memory_breakpoints_cleanup (1);
val = target_read_memory (addr, bundle_mem, BUNDLE_LEN);
+ if (val != 0)
+ {
+ do_cleanups (cleanup);
+ return val;
+ }
+
+ /* SHADOW_SLOTNUM saves the original slot number as expected by the caller
+ for addressing the SHADOW_CONTENTS placement. */
+ shadow_slotnum = slotnum;
- /* Check for L type instruction in slot 1, if present then bump up the slot
- number to the slot 2. */
template = extract_bit_field (bundle_mem, 0, 5);
- if (slotnum == 1 && template_encoding_table[template][slotnum] == L)
- slotnum = 2;
+ if (template_encoding_table[template][slotnum] == X)
+ {
+ /* X unit types can only be used in slot 2, and are actually
+ part of a 2-slot L-X instruction. We refuse to insert
+ breakpoints at this address, so there should be no reason
+ for us attempting to remove one there, except if the program's
+ code somehow got modified in memory. */
+ gdb_assert (slotnum == 2);
+ warning (_("Cannot remove breakpoint at address %s from non-existing "
+ "X-type slot, memory has changed underneath"),
+ paddress (gdbarch, bp_tgt->placed_address));
+ do_cleanups (cleanup);
+ return -1;
+ }
+ if (template_encoding_table[template][slotnum] == L)
+ {
+ /* L unit types can only be used in slot 1. But the breakpoint
+ was actually saved using slot 2, so update the slot number
+ accordingly. */
+ gdb_assert (slotnum == 1);
+ slotnum = 2;
+ }
- gdb_assert (bp_tgt->placed_size == BUNDLE_LEN - 2);
+ gdb_assert (bp_tgt->placed_size == BUNDLE_LEN - shadow_slotnum);
gdb_assert (bp_tgt->placed_size == bp_tgt->shadow_len);
instr_breakpoint = slotN_contents (bundle_mem, slotnum);
warning (_("Cannot remove breakpoint at address %s, "
"no break instruction at such address."),
paddress (gdbarch, bp_tgt->placed_address));
+ do_cleanups (cleanup);
return -1;
}
/* Extract the original saved instruction from SLOTNUM normalizing its
bit-shift for INSTR_SAVED. */
memcpy (bundle_saved, bundle_mem, BUNDLE_LEN);
- memcpy (bundle_saved + slotnum, bp_tgt->shadow_contents, bp_tgt->shadow_len);
+ memcpy (bundle_saved + shadow_slotnum, bp_tgt->shadow_contents,
+ bp_tgt->shadow_len);
instr_saved = slotN_contents (bundle_saved, slotnum);
- /* In BUNDLE_MEM be careful to modify only the bits belonging to SLOTNUM and
- never any other possibly also stored in SHADOW_CONTENTS. */
+ /* In BUNDLE_MEM, be careful to modify only the bits belonging to SLOTNUM
+ and not any of the other ones that are stored in SHADOW_CONTENTS. */
replace_slotN_contents (bundle_mem, instr_saved, slotnum);
- if (val == 0)
- val = target_write_memory (addr, bundle_mem, BUNDLE_LEN);
+ val = target_write_memory (addr, bundle_mem, BUNDLE_LEN);
do_cleanups (cleanup);
return val;
{
CORE_ADDR addr = *pcptr;
static gdb_byte bundle[BUNDLE_LEN];
- int slotnum = (int) (*pcptr & 0x0f) / SLOT_MULTIPLIER;
+ int slotnum = (int) (*pcptr & 0x0f) / SLOT_MULTIPLIER, shadow_slotnum;
long long instr_fetched;
int val;
int template;
if (val != 0)
return NULL;
+ /* SHADOW_SLOTNUM saves the original slot number as expected by the caller
+ for addressing the SHADOW_CONTENTS placement. */
+ shadow_slotnum = slotnum;
+
+ /* Cover always the last byte of the bundle for the L-X slot case. */
+ *lenptr = BUNDLE_LEN - shadow_slotnum;
+
/* Check for L type instruction in slot 1, if present then bump up the slot
number to the slot 2. */
template = extract_bit_field (bundle, 0, 5);
- if (slotnum == 1 && template_encoding_table[template][slotnum] == L)
- slotnum = 2;
+ if (template_encoding_table[template][slotnum] == X)
+ {
+ gdb_assert (slotnum == 2);
+ error (_("Can't insert breakpoint for non-existing slot X"));
+ }
+ if (template_encoding_table[template][slotnum] == L)
+ {
+ gdb_assert (slotnum == 1);
+ slotnum = 2;
+ }
/* A break instruction has its all its opcode bits cleared except for
the parameter value. For L+X slot pair we are at the X slot (slot 2) so
instr_fetched &= 0x1003ffffc0LL;
replace_slotN_contents (bundle, instr_fetched, slotnum);
- *lenptr = BUNDLE_LEN - 2;
-
- /* SLOTNUM is possibly already locally modified - use caller's *PCPTR. */
- return bundle + (*pcptr & 0x0f);
+ return bundle + shadow_slotnum;
}
static CORE_ADDR
ia64_frame_cache (this_frame, this_cache);
/* If outermost frame, mark with null frame id. */
- if (cache->base == 0)
- (*this_id) = null_frame_id;
- else
+ if (cache->base != 0)
(*this_id) = frame_id_build_special (cache->base, cache->pc, cache->bsp);
if (gdbarch_debug >= 1)
fprintf_unfiltered (gdb_stdlog,
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- struct frame_id id;
+ struct frame_id id = outer_frame_id;
char buf[8];
CORE_ADDR bsp;
-
libunwind_frame_this_id (this_frame, this_cache, &id);
- if (frame_id_eq (id, null_frame_id))
+ if (frame_id_eq (id, outer_frame_id))
{
- (*this_id) = null_frame_id;
+ (*this_id) = outer_frame_id;
return;
}
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
char buf[8];
CORE_ADDR bsp;
- struct frame_id id;
+ struct frame_id id = outer_frame_id;
CORE_ADDR prev_ip;
libunwind_frame_this_id (this_frame, this_cache, &id);
- if (frame_id_eq (id, null_frame_id))
+ if (frame_id_eq (id, outer_frame_id))
{
- (*this_id) = null_frame_id;
+ (*this_id) = outer_frame_id;
return;
}
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
struct obj_section *s;
+ gdb_byte buf[8];
s = find_pc_section (addr);
/* Normally, functions live inside a section that is executable.
So, if ADDR points to a non-executable section, then treat it
as a function descriptor and return the target address iff
- the target address itself points to a section that is executable. */
- if (s && (s->the_bfd_section->flags & SEC_CODE) == 0)
+ the target address itself points to a section that is executable.
+ Check first the memory of the whole length of 8 bytes is readable. */
+ if (s && (s->the_bfd_section->flags & SEC_CODE) == 0
+ && target_read_memory (addr, buf, 8) == 0)
{
- CORE_ADDR pc = read_memory_unsigned_integer (addr, 8, byte_order);
+ CORE_ADDR pc = extract_unsigned_integer (buf, 8, byte_order);
struct obj_section *pc_section = find_pc_section (pc);
if (pc_section && (pc_section->the_bfd_section->flags & SEC_CODE))
if (arches != NULL)
return arches->gdbarch;
- tdep = xmalloc (sizeof (struct gdbarch_tdep));
+ tdep = xzalloc (sizeof (struct gdbarch_tdep));
gdbarch = gdbarch_alloc (&info, tdep);
- tdep->sigcontext_register_address = 0;
- tdep->pc_in_sigtramp = 0;
-
/* According to the ia64 specs, instructions that store long double
floats in memory use a long-double format different than that
used in the floating registers. The memory format matches the
projects / deliverable / binutils-gdb.git / blobdiff