OpenE2K/binutils-gdb
12
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

2004-04-22 Randolph Chung <tausq@debian.org>

Browse Source 
* hppa-tdep.h (find_unwind_entry, hppa_get_field, hppa_extract_5_load)
	(hppa_extract_5R_store, hppa_extract_5r_store, hppa_extract_17)
	(hppa_extract_21, hppa_extract_14, hppa_low_sign_extend)
	(hppa_sign_extend): Add prototype.
	* hppa-tdep.c (get_field, extract_5_load, extract_5R_store)
	(extract_5r_store, extract_17, extract_21, extract_14, low_sign_extend)
	(sign_extend): Rename with hppa_ prefix and make non-static.  Other
	hppa targets will also use these functions.
	(find_unwind_entry): Remove prototype (moved to hppa-tdep.h).
	(hppa_in_solib_call_trampoline, hppa_in_solib_return_trampoline)
	(hppa_skip_trampoline_code): Move to hppa-hpux-tdep.c
	(hppa_gdbarch_init): Remove gdbarch setting of
	skip_trampoline_code, in_solib_call_trampoline and
	in_solib_return_trampoline.
	* hppa-hpux-tdep.c (hppa32_hpux_in_solib_call_trampoline)
	(hppa64_hpux_in_solib_call_trampoline): New functions, split from
	hppa_in_solib_call_trampoline.
	(hppa_hpux_in_solib_return_trampoline, hppa_hpux_skip_trampoline_code):
	Moved from hppa-tdep.c.
 	(hppa_hpux_init_abi): Set gdbarch for skip_trampoline_code,
	in_solib_call_trampoline and in_solib_return_trampoline.
This commit is contained in:
Randolph Chung 2004-04-23 02:54:21 +00:00
parent 369aa52037
commit abc485a155
4 changed files with 604 additions and 579 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
gdb/ChangeLog
View File

@ -1,3 +1,27 @@
2004-04-22 Randolph Chung <tausq@debian.org>
* hppa-tdep.h (find_unwind_entry, hppa_get_field, hppa_extract_5_load)
(hppa_extract_5R_store, hppa_extract_5r_store, hppa_extract_17)
(hppa_extract_21, hppa_extract_14, hppa_low_sign_extend)
(hppa_sign_extend): Add prototype.
* hppa-tdep.c (get_field, extract_5_load, extract_5R_store)
(extract_5r_store, extract_17, extract_21, extract_14, low_sign_extend)
(sign_extend): Rename with hppa_ prefix and make non-static. Other
hppa targets will also use these functions.
(find_unwind_entry): Remove prototype (moved to hppa-tdep.h).
(hppa_in_solib_call_trampoline, hppa_in_solib_return_trampoline)
(hppa_skip_trampoline_code): Move to hppa-hpux-tdep.c
(hppa_gdbarch_init): Remove gdbarch setting of
skip_trampoline_code, in_solib_call_trampoline and
in_solib_return_trampoline.
* hppa-hpux-tdep.c (hppa32_hpux_in_solib_call_trampoline)
(hppa64_hpux_in_solib_call_trampoline): New functions, split from
hppa_in_solib_call_trampoline.
(hppa_hpux_in_solib_return_trampoline, hppa_hpux_skip_trampoline_code):
Moved from hppa-tdep.c.
(hppa_hpux_init_abi): Set gdbarch for skip_trampoline_code,
in_solib_call_trampoline and in_solib_return_trampoline.
2004-04-22 Randolph Chung <tausq@debian.org>
* hppa-tdep.c (hppa_debug): New variable.

522
gdb/hppa-hpux-tdep.c
View File

@ -164,6 +164,515 @@ hppa64_hpux_frame_find_saved_regs_in_sigtramp (struct frame_info *fi,
}
}
/* Return one if PC is in the call path of a trampoline, else return zero.
Note we return one for *any* call trampoline (long-call, arg-reloc), not
just shared library trampolines (import, export). */
static int
hppa32_hpux_in_solib_call_trampoline (CORE_ADDR pc, char *name)
{
struct minimal_symbol *minsym;
struct unwind_table_entry *u;
static CORE_ADDR dyncall = 0;
static CORE_ADDR sr4export = 0;
/* FIXME XXX - dyncall and sr4export must be initialized whenever we get a
new exec file */
/* First see if PC is in one of the two C-library trampolines. */
if (!dyncall)
{
minsym = lookup_minimal_symbol ("$$dyncall", NULL, NULL);
if (minsym)
dyncall = SYMBOL_VALUE_ADDRESS (minsym);
else
dyncall = -1;
}
if (!sr4export)
{
minsym = lookup_minimal_symbol ("_sr4export", NULL, NULL);
if (minsym)
sr4export = SYMBOL_VALUE_ADDRESS (minsym);
else
sr4export = -1;
}
if (pc == dyncall || pc == sr4export)
return 1;
minsym = lookup_minimal_symbol_by_pc (pc);
if (minsym && strcmp (DEPRECATED_SYMBOL_NAME (minsym), ".stub") == 0)
return 1;
/* Get the unwind descriptor corresponding to PC, return zero
if no unwind was found. */
u = find_unwind_entry (pc);
if (!u)
return 0;
/* If this isn't a linker stub, then return now. */
if (u->stub_unwind.stub_type == 0)
return 0;
/* By definition a long-branch stub is a call stub. */
if (u->stub_unwind.stub_type == LONG_BRANCH)
return 1;
/* The call and return path execute the same instructions within
an IMPORT stub! So an IMPORT stub is both a call and return
trampoline. */
if (u->stub_unwind.stub_type == IMPORT)
return 1;
/* Parameter relocation stubs always have a call path and may have a
return path. */
if (u->stub_unwind.stub_type == PARAMETER_RELOCATION
|| u->stub_unwind.stub_type == EXPORT)
{
CORE_ADDR addr;
/* Search forward from the current PC until we hit a branch
or the end of the stub. */
for (addr = pc; addr <= u->region_end; addr += 4)
{
unsigned long insn;
insn = read_memory_integer (addr, 4);
/* Does it look like a bl? If so then it's the call path, if
we find a bv or be first, then we're on the return path. */
if ((insn & 0xfc00e000) == 0xe8000000)
return 1;
else if ((insn & 0xfc00e001) == 0xe800c000
|| (insn & 0xfc000000) == 0xe0000000)
return 0;
}
/* Should never happen. */
warning ("Unable to find branch in parameter relocation stub.\n");
return 0;
}
/* Unknown stub type. For now, just return zero. */
return 0;
}
static int
hppa64_hpux_in_solib_call_trampoline (CORE_ADDR pc, char *name)
{
/* PA64 has a completely different stub/trampoline scheme. Is it
better? Maybe. It's certainly harder to determine with any
certainty that we are in a stub because we can not refer to the
unwinders to help.
The heuristic is simple. Try to lookup the current PC value in th
minimal symbol table. If that fails, then assume we are not in a
stub and return.
Then see if the PC value falls within the section bounds for the
section containing the minimal symbol we found in the first
step. If it does, then assume we are not in a stub and return.
Finally peek at the instructions to see if they look like a stub. */
struct minimal_symbol *minsym;
asection *sec;
CORE_ADDR addr;
int insn, i;
minsym = lookup_minimal_symbol_by_pc (pc);
if (! minsym)
return 0;
sec = SYMBOL_BFD_SECTION (minsym);
if (bfd_get_section_vma (sec->owner, sec) <= pc
&& pc < (bfd_get_section_vma (sec->owner, sec)
+ bfd_section_size (sec->owner, sec)))
return 0;
/* We might be in a stub. Peek at the instructions. Stubs are 3
instructions long. */
insn = read_memory_integer (pc, 4);
/* Find out where we think we are within the stub. */
if ((insn & 0xffffc00e) == 0x53610000)
addr = pc;
else if ((insn & 0xffffffff) == 0xe820d000)
addr = pc - 4;
else if ((insn & 0xffffc00e) == 0x537b0000)
addr = pc - 8;
else
return 0;
/* Now verify each insn in the range looks like a stub instruction. */
insn = read_memory_integer (addr, 4);
if ((insn & 0xffffc00e) != 0x53610000)
return 0;
/* Now verify each insn in the range looks like a stub instruction. */
insn = read_memory_integer (addr + 4, 4);
if ((insn & 0xffffffff) != 0xe820d000)
return 0;
/* Now verify each insn in the range looks like a stub instruction. */
insn = read_memory_integer (addr + 8, 4);
if ((insn & 0xffffc00e) != 0x537b0000)
return 0;
/* Looks like a stub. */
return 1;
}
/* Return one if PC is in the return path of a trampoline, else return zero.
Note we return one for *any* call trampoline (long-call, arg-reloc), not
just shared library trampolines (import, export). */
static int
hppa_hpux_in_solib_return_trampoline (CORE_ADDR pc, char *name)
{
struct unwind_table_entry *u;
/* Get the unwind descriptor corresponding to PC, return zero
if no unwind was found. */
u = find_unwind_entry (pc);
if (!u)
return 0;
/* If this isn't a linker stub or it's just a long branch stub, then
return zero. */
if (u->stub_unwind.stub_type == 0 || u->stub_unwind.stub_type == LONG_BRANCH)
return 0;
/* The call and return path execute the same instructions within
an IMPORT stub! So an IMPORT stub is both a call and return
trampoline. */
if (u->stub_unwind.stub_type == IMPORT)
return 1;
/* Parameter relocation stubs always have a call path and may have a
return path. */
if (u->stub_unwind.stub_type == PARAMETER_RELOCATION
|| u->stub_unwind.stub_type == EXPORT)
{
CORE_ADDR addr;
/* Search forward from the current PC until we hit a branch
or the end of the stub. */
for (addr = pc; addr <= u->region_end; addr += 4)
{
unsigned long insn;
insn = read_memory_integer (addr, 4);
/* Does it look like a bl? If so then it's the call path, if
we find a bv or be first, then we're on the return path. */
if ((insn & 0xfc00e000) == 0xe8000000)
return 0;
else if ((insn & 0xfc00e001) == 0xe800c000
|| (insn & 0xfc000000) == 0xe0000000)
return 1;
}
/* Should never happen. */
warning ("Unable to find branch in parameter relocation stub.\n");
return 0;
}
/* Unknown stub type. For now, just return zero. */
return 0;
}
/* Figure out if PC is in a trampoline, and if so find out where
the trampoline will jump to. If not in a trampoline, return zero.
Simple code examination probably is not a good idea since the code
sequences in trampolines can also appear in user code.
We use unwinds and information from the minimal symbol table to
determine when we're in a trampoline. This won't work for ELF
(yet) since it doesn't create stub unwind entries. Whether or
not ELF will create stub unwinds or normal unwinds for linker
stubs is still being debated.
This should handle simple calls through dyncall or sr4export,
long calls, argument relocation stubs, and dyncall/sr4export
calling an argument relocation stub. It even handles some stubs
used in dynamic executables. */
static CORE_ADDR
hppa_hpux_skip_trampoline_code (CORE_ADDR pc)
{
long orig_pc = pc;
long prev_inst, curr_inst, loc;
static CORE_ADDR dyncall = 0;
static CORE_ADDR dyncall_external = 0;
static CORE_ADDR sr4export = 0;
struct minimal_symbol *msym;
struct unwind_table_entry *u;
/* FIXME XXX - dyncall and sr4export must be initialized whenever we get a
new exec file */
if (!dyncall)
{
msym = lookup_minimal_symbol ("$$dyncall", NULL, NULL);
if (msym)
dyncall = SYMBOL_VALUE_ADDRESS (msym);
else
dyncall = -1;
}
if (!dyncall_external)
{
msym = lookup_minimal_symbol ("$$dyncall_external", NULL, NULL);
if (msym)
dyncall_external = SYMBOL_VALUE_ADDRESS (msym);
else
dyncall_external = -1;
}
if (!sr4export)
{
msym = lookup_minimal_symbol ("_sr4export", NULL, NULL);
if (msym)
sr4export = SYMBOL_VALUE_ADDRESS (msym);
else
sr4export = -1;
}
/* Addresses passed to dyncall may *NOT* be the actual address
of the function. So we may have to do something special. */
if (pc == dyncall)
{
pc = (CORE_ADDR) read_register (22);
/* If bit 30 (counting from the left) is on, then pc is the address of
the PLT entry for this function, not the address of the function
itself. Bit 31 has meaning too, but only for MPE. */
if (pc & 0x2)
pc = (CORE_ADDR) read_memory_integer (pc & ~0x3, TARGET_PTR_BIT / 8);
}
if (pc == dyncall_external)
{
pc = (CORE_ADDR) read_register (22);
pc = (CORE_ADDR) read_memory_integer (pc & ~0x3, TARGET_PTR_BIT / 8);
}
else if (pc == sr4export)
pc = (CORE_ADDR) (read_register (22));
/* Get the unwind descriptor corresponding to PC, return zero
if no unwind was found. */
u = find_unwind_entry (pc);
if (!u)
return 0;
/* If this isn't a linker stub, then return now. */
/* elz: attention here! (FIXME) because of a compiler/linker
error, some stubs which should have a non zero stub_unwind.stub_type
have unfortunately a value of zero. So this function would return here
as if we were not in a trampoline. To fix this, we go look at the partial
symbol information, which reports this guy as a stub.
(FIXME): Unfortunately, we are not that lucky: it turns out that the
partial symbol information is also wrong sometimes. This is because
when it is entered (somread.c::som_symtab_read()) it can happen that
if the type of the symbol (from the som) is Entry, and the symbol is
in a shared library, then it can also be a trampoline. This would
be OK, except that I believe the way they decide if we are ina shared library
does not work. SOOOO..., even if we have a regular function w/o trampolines
its minimal symbol can be assigned type mst_solib_trampoline.
Also, if we find that the symbol is a real stub, then we fix the unwind
descriptor, and define the stub type to be EXPORT.
Hopefully this is correct most of the times. */
if (u->stub_unwind.stub_type == 0)
{
/* elz: NOTE (FIXME!) once the problem with the unwind information is fixed
we can delete all the code which appears between the lines */
/*--------------------------------------------------------------------------*/
msym = lookup_minimal_symbol_by_pc (pc);
if (msym == NULL || MSYMBOL_TYPE (msym) != mst_solib_trampoline)
return orig_pc == pc ? 0 : pc & ~0x3;
else if (msym != NULL && MSYMBOL_TYPE (msym) == mst_solib_trampoline)
{
struct objfile *objfile;
struct minimal_symbol *msymbol;
int function_found = 0;
/* go look if there is another minimal symbol with the same name as
this one, but with type mst_text. This would happen if the msym
is an actual trampoline, in which case there would be another
symbol with the same name corresponding to the real function */
ALL_MSYMBOLS (objfile, msymbol)
{
if (MSYMBOL_TYPE (msymbol) == mst_text
&& DEPRECATED_STREQ (DEPRECATED_SYMBOL_NAME (msymbol), DEPRECATED_SYMBOL_NAME (msym)))
{
function_found = 1;
break;
}
}
if (function_found)
/* the type of msym is correct (mst_solib_trampoline), but
the unwind info is wrong, so set it to the correct value */
u->stub_unwind.stub_type = EXPORT;
else
/* the stub type info in the unwind is correct (this is not a
trampoline), but the msym type information is wrong, it
should be mst_text. So we need to fix the msym, and also
get out of this function */
{
MSYMBOL_TYPE (msym) = mst_text;
return orig_pc == pc ? 0 : pc & ~0x3;
}
}
/*--------------------------------------------------------------------------*/
}
/* It's a stub. Search for a branch and figure out where it goes.
Note we have to handle multi insn branch sequences like ldil;ble.
Most (all?) other branches can be determined by examining the contents
of certain registers and the stack. */
loc = pc;
curr_inst = 0;
prev_inst = 0;
while (1)
{
/* Make sure we haven't walked outside the range of this stub. */
if (u != find_unwind_entry (loc))
{
warning ("Unable to find branch in linker stub");
return orig_pc == pc ? 0 : pc & ~0x3;
}
prev_inst = curr_inst;
curr_inst = read_memory_integer (loc, 4);
/* Does it look like a branch external using %r1? Then it's the
branch from the stub to the actual function. */
if ((curr_inst & 0xffe0e000) == 0xe0202000)
{
/* Yup. See if the previous instruction loaded
a value into %r1. If so compute and return the jump address. */
if ((prev_inst & 0xffe00000) == 0x20200000)
return (hppa_extract_21 (prev_inst) + hppa_extract_17 (curr_inst)) & ~0x3;
else
{
warning ("Unable to find ldil X,%%r1 before ble Y(%%sr4,%%r1).");
return orig_pc == pc ? 0 : pc & ~0x3;
}
}
/* Does it look like a be 0(sr0,%r21)? OR
Does it look like a be, n 0(sr0,%r21)? OR
Does it look like a bve (r21)? (this is on PA2.0)
Does it look like a bve, n(r21)? (this is also on PA2.0)
That's the branch from an
import stub to an export stub.
It is impossible to determine the target of the branch via
simple examination of instructions and/or data (consider
that the address in the plabel may be the address of the
bind-on-reference routine in the dynamic loader).
So we have try an alternative approach.
Get the name of the symbol at our current location; it should
be a stub symbol with the same name as the symbol in the
shared library.
Then lookup a minimal symbol with the same name; we should
get the minimal symbol for the target routine in the shared
library as those take precedence of import/export stubs. */
if ((curr_inst == 0xe2a00000) ||
(curr_inst == 0xe2a00002) ||
(curr_inst == 0xeaa0d000) ||
(curr_inst == 0xeaa0d002))
{
struct minimal_symbol *stubsym, *libsym;
stubsym = lookup_minimal_symbol_by_pc (loc);
if (stubsym == NULL)
{
warning ("Unable to find symbol for 0x%lx", loc);
return orig_pc == pc ? 0 : pc & ~0x3;
}
libsym = lookup_minimal_symbol (DEPRECATED_SYMBOL_NAME (stubsym), NULL, NULL);
if (libsym == NULL)
{
warning ("Unable to find library symbol for %s\n",
DEPRECATED_SYMBOL_NAME (stubsym));
return orig_pc == pc ? 0 : pc & ~0x3;
}
return SYMBOL_VALUE (libsym);
}
/* Does it look like bl X,%rp or bl X,%r0? Another way to do a
branch from the stub to the actual function. */
/*elz */
else if ((curr_inst & 0xffe0e000) == 0xe8400000
|| (curr_inst & 0xffe0e000) == 0xe8000000
|| (curr_inst & 0xffe0e000) == 0xe800A000)
return (loc + hppa_extract_17 (curr_inst) + 8) & ~0x3;
/* Does it look like bv (rp)? Note this depends on the
current stack pointer being the same as the stack
pointer in the stub itself! This is a branch on from the
stub back to the original caller. */
/*else if ((curr_inst & 0xffe0e000) == 0xe840c000) */
else if ((curr_inst & 0xffe0f000) == 0xe840c000)
{
/* Yup. See if the previous instruction loaded
rp from sp - 8. */
if (prev_inst == 0x4bc23ff1)
return (read_memory_integer
(read_register (HPPA_SP_REGNUM) - 8, 4)) & ~0x3;
else
{
warning ("Unable to find restore of %%rp before bv (%%rp).");
return orig_pc == pc ? 0 : pc & ~0x3;
}
}
/* elz: added this case to capture the new instruction
at the end of the return part of an export stub used by
the PA2.0: BVE, n (rp) */
else if ((curr_inst & 0xffe0f000) == 0xe840d000)
{
return (read_memory_integer
(read_register (HPPA_SP_REGNUM) - 24, TARGET_PTR_BIT / 8)) & ~0x3;
}
/* What about be,n 0(sr0,%rp)? It's just another way we return to
the original caller from the stub. Used in dynamic executables. */
else if (curr_inst == 0xe0400002)
{
/* The value we jump to is sitting in sp - 24. But that's
loaded several instructions before the be instruction.
I guess we could check for the previous instruction being
mtsp %r1,%sr0 if we want to do sanity checking. */
return (read_memory_integer
(read_register (HPPA_SP_REGNUM) - 24, TARGET_PTR_BIT / 8)) & ~0x3;
}
/* Haven't found the branch yet, but we're still in the stub.
Keep looking. */
loc += 4;
}
}
/* Exception handling support for the HP-UX ANSI C++ compiler.
The compiler (aCC) provides a callback for exception events;
GDB can set a breakpoint on this callback and find out what
@ -716,7 +1225,20 @@ child_get_current_exception_event (void)
static void
hppa_hpux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
set_gdbarch_deprecated_pc_in_sigtramp (gdbarch, hppa_hpux_pc_in_sigtramp);
if (tdep->bytes_per_address == 4)
set_gdbarch_in_solib_call_trampoline (gdbarch,
hppa32_hpux_in_solib_call_trampoline);
else
set_gdbarch_in_solib_call_trampoline (gdbarch,
hppa64_hpux_in_solib_call_trampoline);
set_gdbarch_in_solib_return_trampoline (gdbarch,
hppa_hpux_in_solib_return_trampoline);
set_gdbarch_skip_trampoline_code (gdbarch, hppa_hpux_skip_trampoline_code);
}
static void

625
gdb/hppa-tdep.c
View File

@ -88,28 +88,8 @@ const struct objfile_data *hppa_objfile_priv_data = NULL;
#define UNWIND_ENTRY_SIZE 16
#define STUB_UNWIND_ENTRY_SIZE 8
static int get_field (unsigned word, int from, int to);
static int extract_5_load (unsigned int);
static unsigned extract_5R_store (unsigned int);
static unsigned extract_5r_store (unsigned int);
struct unwind_table_entry *find_unwind_entry (CORE_ADDR);
static int extract_17 (unsigned int);
static int extract_21 (unsigned);
static int extract_14 (unsigned);
static void unwind_command (char *, int);
static int low_sign_extend (unsigned int, unsigned int);
static int sign_extend (unsigned int, unsigned int);
static int hppa_alignof (struct type *);
static int prologue_inst_adjust_sp (unsigned long);
@ -246,16 +226,16 @@ hppa64_return_value (struct gdbarch *gdbarch,
/* This assumes that no garbage lies outside of the lower bits of
value. */
static int
sign_extend (unsigned val, unsigned bits)
int
hppa_sign_extend (unsigned val, unsigned bits)
{
return (int) (val >> (bits - 1) ? (-1 << bits) | val : val);
}
/* For many immediate values the sign bit is the low bit! */
static int
low_sign_extend (unsigned val, unsigned bits)
int
hppa_low_hppa_sign_extend (unsigned val, unsigned bits)
{
return (int) ((val & 0x1 ? (-1 << (bits - 1)) : 0) | val >> 1);
}
@ -263,74 +243,74 @@ low_sign_extend (unsigned val, unsigned bits)
/* Extract the bits at positions between FROM and TO, using HP's numbering
(MSB = 0). */
static int
get_field (unsigned word, int from, int to)
int
hppa_get_field (unsigned word, int from, int to)
{
return ((word) >> (31 - (to)) & ((1 << ((to) - (from) + 1)) - 1));
}
/* extract the immediate field from a ld{bhw}s instruction */
static int
extract_5_load (unsigned word)
int
hppa_extract_5_load (unsigned word)
{
return low_sign_extend (word >> 16 & MASK_5, 5);
return hppa_low_hppa_sign_extend (word >> 16 & MASK_5, 5);
}
/* extract the immediate field from a break instruction */
static unsigned
extract_5r_store (unsigned word)
unsigned
hppa_extract_5r_store (unsigned word)
{
return (word & MASK_5);
}
/* extract the immediate field from a {sr}sm instruction */
static unsigned
extract_5R_store (unsigned word)
unsigned
hppa_extract_5R_store (unsigned word)
{
return (word >> 16 & MASK_5);
}
/* extract a 14 bit immediate field */
static int
extract_14 (unsigned word)
int
hppa_extract_14 (unsigned word)
{
return low_sign_extend (word & MASK_14, 14);
return hppa_low_hppa_sign_extend (word & MASK_14, 14);
}
/* extract a 21 bit constant */
static int
extract_21 (unsigned word)
int
hppa_extract_21 (unsigned word)
{
int val;
word &= MASK_21;
word <<= 11;
val = get_field (word, 20, 20);
val = hppa_get_field (word, 20, 20);
val <<= 11;
val |= get_field (word, 9, 19);
val |= hppa_get_field (word, 9, 19);
val <<= 2;
val |= get_field (word, 5, 6);
val |= hppa_get_field (word, 5, 6);
val <<= 5;
val |= get_field (word, 0, 4);
val |= hppa_get_field (word, 0, 4);
val <<= 2;
val |= get_field (word, 7, 8);
return sign_extend (val, 21) << 11;
val |= hppa_get_field (word, 7, 8);
return hppa_sign_extend (val, 21) << 11;
}
/* extract a 17 bit constant from branch instructions, returning the
19 bit signed value. */
static int
extract_17 (unsigned word)
int
hppa_extract_17 (unsigned word)
{
return sign_extend (get_field (word, 19, 28) |
get_field (word, 29, 29) << 10 |
get_field (word, 11, 15) << 11 |
return hppa_sign_extend (hppa_get_field (word, 19, 28) |
hppa_get_field (word, 29, 29) << 10 |
hppa_get_field (word, 11, 15) << 11 |
(word & 0x1) << 16, 17) << 2;
}
@ -1099,515 +1079,6 @@ hppa_alignof (struct type *type)
}
}
/* Return one if PC is in the call path of a trampoline, else return zero.
Note we return one for *any* call trampoline (long-call, arg-reloc), not
just shared library trampolines (import, export). */
static int
hppa_in_solib_call_trampoline (CORE_ADDR pc, char *name)
{
struct minimal_symbol *minsym;
struct unwind_table_entry *u;
static CORE_ADDR dyncall = 0;
static CORE_ADDR sr4export = 0;
#ifdef GDB_TARGET_IS_HPPA_20W
/* PA64 has a completely different stub/trampoline scheme. Is it
better? Maybe. It's certainly harder to determine with any
certainty that we are in a stub because we can not refer to the
unwinders to help.
The heuristic is simple. Try to lookup the current PC value in th
minimal symbol table. If that fails, then assume we are not in a
stub and return.
Then see if the PC value falls within the section bounds for the
section containing the minimal symbol we found in the first
step. If it does, then assume we are not in a stub and return.
Finally peek at the instructions to see if they look like a stub. */
{
struct minimal_symbol *minsym;
asection *sec;
CORE_ADDR addr;
int insn, i;
minsym = lookup_minimal_symbol_by_pc (pc);
if (! minsym)
return 0;
sec = SYMBOL_BFD_SECTION (minsym);
if (bfd_get_section_vma (sec->owner, sec) <= pc
&& pc < (bfd_get_section_vma (sec->owner, sec)
+ bfd_section_size (sec->owner, sec)))
return 0;
/* We might be in a stub. Peek at the instructions. Stubs are 3
instructions long. */
insn = read_memory_integer (pc, 4);
/* Find out where we think we are within the stub. */
if ((insn & 0xffffc00e) == 0x53610000)
addr = pc;
else if ((insn & 0xffffffff) == 0xe820d000)
addr = pc - 4;
else if ((insn & 0xffffc00e) == 0x537b0000)
addr = pc - 8;
else
return 0;
/* Now verify each insn in the range looks like a stub instruction. */
insn = read_memory_integer (addr, 4);
if ((insn & 0xffffc00e) != 0x53610000)
return 0;
/* Now verify each insn in the range looks like a stub instruction. */
insn = read_memory_integer (addr + 4, 4);
if ((insn & 0xffffffff) != 0xe820d000)
return 0;
/* Now verify each insn in the range looks like a stub instruction. */
insn = read_memory_integer (addr + 8, 4);
if ((insn & 0xffffc00e) != 0x537b0000)
return 0;
/* Looks like a stub. */
return 1;
}
#endif
/* FIXME XXX - dyncall and sr4export must be initialized whenever we get a
new exec file */
/* First see if PC is in one of the two C-library trampolines. */
if (!dyncall)
{
minsym = lookup_minimal_symbol ("$$dyncall", NULL, NULL);
if (minsym)
dyncall = SYMBOL_VALUE_ADDRESS (minsym);
else
dyncall = -1;
}
if (!sr4export)
{
minsym = lookup_minimal_symbol ("_sr4export", NULL, NULL);
if (minsym)
sr4export = SYMBOL_VALUE_ADDRESS (minsym);
else
sr4export = -1;
}
if (pc == dyncall || pc == sr4export)
return 1;
minsym = lookup_minimal_symbol_by_pc (pc);
if (minsym && strcmp (DEPRECATED_SYMBOL_NAME (minsym), ".stub") == 0)
return 1;
/* Get the unwind descriptor corresponding to PC, return zero
if no unwind was found. */
u = find_unwind_entry (pc);
if (!u)
return 0;
/* If this isn't a linker stub, then return now. */
if (u->stub_unwind.stub_type == 0)
return 0;
/* By definition a long-branch stub is a call stub. */
if (u->stub_unwind.stub_type == LONG_BRANCH)
return 1;
/* The call and return path execute the same instructions within
an IMPORT stub! So an IMPORT stub is both a call and return
trampoline. */
if (u->stub_unwind.stub_type == IMPORT)
return 1;
/* Parameter relocation stubs always have a call path and may have a
return path. */
if (u->stub_unwind.stub_type == PARAMETER_RELOCATION
|| u->stub_unwind.stub_type == EXPORT)
{
CORE_ADDR addr;
/* Search forward from the current PC until we hit a branch
or the end of the stub. */
for (addr = pc; addr <= u->region_end; addr += 4)
{
unsigned long insn;
insn = read_memory_integer (addr, 4);
/* Does it look like a bl? If so then it's the call path, if
we find a bv or be first, then we're on the return path. */
if ((insn & 0xfc00e000) == 0xe8000000)
return 1;
else if ((insn & 0xfc00e001) == 0xe800c000
|| (insn & 0xfc000000) == 0xe0000000)
return 0;
}
/* Should never happen. */
warning ("Unable to find branch in parameter relocation stub.\n");
return 0;
}
/* Unknown stub type. For now, just return zero. */
return 0;
}
/* Return one if PC is in the return path of a trampoline, else return zero.
Note we return one for *any* call trampoline (long-call, arg-reloc), not
just shared library trampolines (import, export). */
static int
hppa_in_solib_return_trampoline (CORE_ADDR pc, char *name)
{
struct unwind_table_entry *u;
/* Get the unwind descriptor corresponding to PC, return zero
if no unwind was found. */
u = find_unwind_entry (pc);
if (!u)
return 0;
/* If this isn't a linker stub or it's just a long branch stub, then
return zero. */
if (u->stub_unwind.stub_type == 0 || u->stub_unwind.stub_type == LONG_BRANCH)
return 0;
/* The call and return path execute the same instructions within
an IMPORT stub! So an IMPORT stub is both a call and return
trampoline. */
if (u->stub_unwind.stub_type == IMPORT)
return 1;
/* Parameter relocation stubs always have a call path and may have a
return path. */
if (u->stub_unwind.stub_type == PARAMETER_RELOCATION
|| u->stub_unwind.stub_type == EXPORT)
{
CORE_ADDR addr;
/* Search forward from the current PC until we hit a branch
or the end of the stub. */
for (addr = pc; addr <= u->region_end; addr += 4)
{
unsigned long insn;
insn = read_memory_integer (addr, 4);
/* Does it look like a bl? If so then it's the call path, if
we find a bv or be first, then we're on the return path. */
if ((insn & 0xfc00e000) == 0xe8000000)
return 0;
else if ((insn & 0xfc00e001) == 0xe800c000
|| (insn & 0xfc000000) == 0xe0000000)
return 1;
}
/* Should never happen. */
warning ("Unable to find branch in parameter relocation stub.\n");
return 0;
}
/* Unknown stub type. For now, just return zero. */
return 0;
}
/* Figure out if PC is in a trampoline, and if so find out where
the trampoline will jump to. If not in a trampoline, return zero.
Simple code examination probably is not a good idea since the code
sequences in trampolines can also appear in user code.
We use unwinds and information from the minimal symbol table to
determine when we're in a trampoline. This won't work for ELF
(yet) since it doesn't create stub unwind entries. Whether or
not ELF will create stub unwinds or normal unwinds for linker
stubs is still being debated.
This should handle simple calls through dyncall or sr4export,
long calls, argument relocation stubs, and dyncall/sr4export
calling an argument relocation stub. It even handles some stubs
used in dynamic executables. */
static CORE_ADDR
hppa_skip_trampoline_code (CORE_ADDR pc)
{
long orig_pc = pc;
long prev_inst, curr_inst, loc;
static CORE_ADDR dyncall = 0;
static CORE_ADDR dyncall_external = 0;
static CORE_ADDR sr4export = 0;
struct minimal_symbol *msym;
struct unwind_table_entry *u;
/* FIXME XXX - dyncall and sr4export must be initialized whenever we get a
new exec file */
if (!dyncall)
{
msym = lookup_minimal_symbol ("$$dyncall", NULL, NULL);
if (msym)
dyncall = SYMBOL_VALUE_ADDRESS (msym);
else
dyncall = -1;
}
if (!dyncall_external)
{
msym = lookup_minimal_symbol ("$$dyncall_external", NULL, NULL);
if (msym)
dyncall_external = SYMBOL_VALUE_ADDRESS (msym);
else
dyncall_external = -1;
}
if (!sr4export)
{
msym = lookup_minimal_symbol ("_sr4export", NULL, NULL);
if (msym)
sr4export = SYMBOL_VALUE_ADDRESS (msym);
else
sr4export = -1;
}
/* Addresses passed to dyncall may *NOT* be the actual address
of the function. So we may have to do something special. */
if (pc == dyncall)
{
pc = (CORE_ADDR) read_register (22);
/* If bit 30 (counting from the left) is on, then pc is the address of
the PLT entry for this function, not the address of the function
itself. Bit 31 has meaning too, but only for MPE. */
if (pc & 0x2)
pc = (CORE_ADDR) read_memory_integer (pc & ~0x3, TARGET_PTR_BIT / 8);
}
if (pc == dyncall_external)
{
pc = (CORE_ADDR) read_register (22);
pc = (CORE_ADDR) read_memory_integer (pc & ~0x3, TARGET_PTR_BIT / 8);
}
else if (pc == sr4export)
pc = (CORE_ADDR) (read_register (22));
/* Get the unwind descriptor corresponding to PC, return zero
if no unwind was found. */
u = find_unwind_entry (pc);
if (!u)
return 0;
/* If this isn't a linker stub, then return now. */
/* elz: attention here! (FIXME) because of a compiler/linker
error, some stubs which should have a non zero stub_unwind.stub_type
have unfortunately a value of zero. So this function would return here
as if we were not in a trampoline. To fix this, we go look at the partial
symbol information, which reports this guy as a stub.
(FIXME): Unfortunately, we are not that lucky: it turns out that the
partial symbol information is also wrong sometimes. This is because
when it is entered (somread.c::som_symtab_read()) it can happen that
if the type of the symbol (from the som) is Entry, and the symbol is
in a shared library, then it can also be a trampoline. This would
be OK, except that I believe the way they decide if we are ina shared library
does not work. SOOOO..., even if we have a regular function w/o trampolines
its minimal symbol can be assigned type mst_solib_trampoline.
Also, if we find that the symbol is a real stub, then we fix the unwind
descriptor, and define the stub type to be EXPORT.
Hopefully this is correct most of the times. */
if (u->stub_unwind.stub_type == 0)
{
/* elz: NOTE (FIXME!) once the problem with the unwind information is fixed
we can delete all the code which appears between the lines */
/*--------------------------------------------------------------------------*/
msym = lookup_minimal_symbol_by_pc (pc);
if (msym == NULL || MSYMBOL_TYPE (msym) != mst_solib_trampoline)
return orig_pc == pc ? 0 : pc & ~0x3;
else if (msym != NULL && MSYMBOL_TYPE (msym) == mst_solib_trampoline)
{
struct objfile *objfile;
struct minimal_symbol *msymbol;
int function_found = 0;
/* go look if there is another minimal symbol with the same name as
this one, but with type mst_text. This would happen if the msym
is an actual trampoline, in which case there would be another
symbol with the same name corresponding to the real function */
ALL_MSYMBOLS (objfile, msymbol)
{
if (MSYMBOL_TYPE (msymbol) == mst_text
&& DEPRECATED_STREQ (DEPRECATED_SYMBOL_NAME (msymbol), DEPRECATED_SYMBOL_NAME (msym)))
{
function_found = 1;
break;
}
}
if (function_found)
/* the type of msym is correct (mst_solib_trampoline), but
the unwind info is wrong, so set it to the correct value */
u->stub_unwind.stub_type = EXPORT;
else
/* the stub type info in the unwind is correct (this is not a
trampoline), but the msym type information is wrong, it
should be mst_text. So we need to fix the msym, and also
get out of this function */
{
MSYMBOL_TYPE (msym) = mst_text;
return orig_pc == pc ? 0 : pc & ~0x3;
}
}
/*--------------------------------------------------------------------------*/
}
/* It's a stub. Search for a branch and figure out where it goes.
Note we have to handle multi insn branch sequences like ldil;ble.
Most (all?) other branches can be determined by examining the contents
of certain registers and the stack. */
loc = pc;
curr_inst = 0;
prev_inst = 0;
while (1)
{
/* Make sure we haven't walked outside the range of this stub. */
if (u != find_unwind_entry (loc))
{
warning ("Unable to find branch in linker stub");
return orig_pc == pc ? 0 : pc & ~0x3;
}
prev_inst = curr_inst;
curr_inst = read_memory_integer (loc, 4);
/* Does it look like a branch external using %r1? Then it's the
branch from the stub to the actual function. */
if ((curr_inst & 0xffe0e000) == 0xe0202000)
{
/* Yup. See if the previous instruction loaded
a value into %r1. If so compute and return the jump address. */
if ((prev_inst & 0xffe00000) == 0x20200000)
return (extract_21 (prev_inst) + extract_17 (curr_inst)) & ~0x3;
else
{
warning ("Unable to find ldil X,%%r1 before ble Y(%%sr4,%%r1).");
return orig_pc == pc ? 0 : pc & ~0x3;
}
}
/* Does it look like a be 0(sr0,%r21)? OR
Does it look like a be, n 0(sr0,%r21)? OR
Does it look like a bve (r21)? (this is on PA2.0)
Does it look like a bve, n(r21)? (this is also on PA2.0)
That's the branch from an
import stub to an export stub.
It is impossible to determine the target of the branch via
simple examination of instructions and/or data (consider
that the address in the plabel may be the address of the
bind-on-reference routine in the dynamic loader).
So we have try an alternative approach.
Get the name of the symbol at our current location; it should
be a stub symbol with the same name as the symbol in the
shared library.
Then lookup a minimal symbol with the same name; we should
get the minimal symbol for the target routine in the shared
library as those take precedence of import/export stubs. */
if ((curr_inst == 0xe2a00000) ||
(curr_inst == 0xe2a00002) ||
(curr_inst == 0xeaa0d000) ||
(curr_inst == 0xeaa0d002))
{
struct minimal_symbol *stubsym, *libsym;
stubsym = lookup_minimal_symbol_by_pc (loc);
if (stubsym == NULL)
{
warning ("Unable to find symbol for 0x%lx", loc);
return orig_pc == pc ? 0 : pc & ~0x3;
}
libsym = lookup_minimal_symbol (DEPRECATED_SYMBOL_NAME (stubsym), NULL, NULL);
if (libsym == NULL)
{
warning ("Unable to find library symbol for %s\n",
DEPRECATED_SYMBOL_NAME (stubsym));
return orig_pc == pc ? 0 : pc & ~0x3;
}
return SYMBOL_VALUE (libsym);
}
/* Does it look like bl X,%rp or bl X,%r0? Another way to do a
branch from the stub to the actual function. */
/*elz */
else if ((curr_inst & 0xffe0e000) == 0xe8400000
|| (curr_inst & 0xffe0e000) == 0xe8000000
|| (curr_inst & 0xffe0e000) == 0xe800A000)
return (loc + extract_17 (curr_inst) + 8) & ~0x3;
/* Does it look like bv (rp)? Note this depends on the
current stack pointer being the same as the stack
pointer in the stub itself! This is a branch on from the
stub back to the original caller. */
/*else if ((curr_inst & 0xffe0e000) == 0xe840c000) */
else if ((curr_inst & 0xffe0f000) == 0xe840c000)
{
/* Yup. See if the previous instruction loaded
rp from sp - 8. */
if (prev_inst == 0x4bc23ff1)
return (read_memory_integer
(read_register (HPPA_SP_REGNUM) - 8, 4)) & ~0x3;
else
{
warning ("Unable to find restore of %%rp before bv (%%rp).");
return orig_pc == pc ? 0 : pc & ~0x3;
}
}
/* elz: added this case to capture the new instruction
at the end of the return part of an export stub used by
the PA2.0: BVE, n (rp) */
else if ((curr_inst & 0xffe0f000) == 0xe840d000)
{
return (read_memory_integer
(read_register (HPPA_SP_REGNUM) - 24, TARGET_PTR_BIT / 8)) & ~0x3;
}
/* What about be,n 0(sr0,%rp)? It's just another way we return to
the original caller from the stub. Used in dynamic executables. */
else if (curr_inst == 0xe0400002)
{
/* The value we jump to is sitting in sp - 24. But that's
loaded several instructions before the be instruction.
I guess we could check for the previous instruction being
mtsp %r1,%sr0 if we want to do sanity checking. */
return (read_memory_integer
(read_register (HPPA_SP_REGNUM) - 24, TARGET_PTR_BIT / 8)) & ~0x3;
}
/* Haven't found the branch yet, but we're still in the stub.
Keep looking. */
loc += 4;
}
}
/* For the given instruction (INST), return any adjustment it makes
to the stack pointer or zero for no adjustment.
@ -1621,11 +1092,11 @@ prologue_inst_adjust_sp (unsigned long inst)
/* The most common way to perform a stack adjustment ldo X(sp),sp */
if ((inst & 0xffffc000) == 0x37de0000)
return extract_14 (inst);
return hppa_extract_14 (inst);
/* stwm X,D(sp) */
if ((inst & 0xffe00000) == 0x6fc00000)
return extract_14 (inst);
return hppa_extract_14 (inst);
/* std,ma X,D(sp) */
if ((inst & 0xffe00008) == 0x73c00008)
@ -1635,16 +1106,16 @@ prologue_inst_adjust_sp (unsigned long inst)
save high bits in save_high21 for later use. */
if ((inst & 0xffe00000) == 0x28200000)
{
save_high21 = extract_21 (inst);
save_high21 = hppa_extract_21 (inst);
return 0;
}
if ((inst & 0xffff0000) == 0x343e0000)
return save_high21 + extract_14 (inst);
return save_high21 + hppa_extract_14 (inst);
/* fstws as used by the HP compilers. */
if ((inst & 0xffffffe0) == 0x2fd01220)
return extract_5_load (inst);
return hppa_extract_5_load (inst);
/* No adjustment. */
return 0;
@ -1693,17 +1164,17 @@ inst_saves_gr (unsigned long inst)
|| (inst >> 26) == 0x1f
|| ((inst >> 26) == 0x1f
&& ((inst >> 6) == 0xa)))
return extract_5R_store (inst);
return hppa_extract_5R_store (inst);
/* Does it look like a std? */
if ((inst >> 26) == 0x1c
|| ((inst >> 26) == 0x03
&& ((inst >> 6) & 0xf) == 0xb))
return extract_5R_store (inst);
return hppa_extract_5R_store (inst);
/* Does it look like a stwm? GCC & HPC may use this in prologues. */
if ((inst >> 26) == 0x1b)
return extract_5R_store (inst);
return hppa_extract_5R_store (inst);
/* Does it look like sth or stb? HPC versions 9.0 and later use these
too. */
@ -1711,7 +1182,7 @@ inst_saves_gr (unsigned long inst)
|| ((inst >> 26) == 0x3
&& (((inst >> 6) & 0xf) == 0x8
|| (inst >> 6) & 0xf) == 0x9))
return extract_5R_store (inst);
return hppa_extract_5R_store (inst);
return 0;
}
@ -1729,14 +1200,14 @@ inst_saves_fr (unsigned long inst)
{
/* is this an FSTD ? */
if ((inst & 0xfc00dfc0) == 0x2c001200)
return extract_5r_store (inst);
return hppa_extract_5r_store (inst);
if ((inst & 0xfc000002) == 0x70000002)
return extract_5R_store (inst);
return hppa_extract_5R_store (inst);
/* is this an FSTW ? */
if ((inst & 0xfc00df80) == 0x24001200)
return extract_5r_store (inst);
return hppa_extract_5r_store (inst);
if ((inst & 0xfc000002) == 0x7c000000)
return extract_5R_store (inst);
return hppa_extract_5R_store (inst);
return 0;
}
@ -2172,7 +1643,7 @@ hppa_frame_cache (struct frame_info *next_frame, void **this_cache)
&& (!u->Save_SP || reg != HPPA_FP_REGNUM))
{
saved_gr_mask &= ~(1 << reg);
if ((inst >> 26) == 0x1b && extract_14 (inst) >= 0)
if ((inst >> 26) == 0x1b && hppa_extract_14 (inst) >= 0)
/* stwm with a positive displacement is a _post_
_modify_. */
cache->saved_regs[reg].addr = 0;
@ -2186,9 +1657,9 @@ hppa_frame_cache (struct frame_info *next_frame, void **this_cache)
if ((inst >> 26) == 0x1c)
offset = (inst & 0x1 ? -1 << 13 : 0) | (((inst >> 4) & 0x3ff) << 3);
else if ((inst >> 26) == 0x03)
offset = low_sign_extend (inst & 0x1f, 5);
offset = hppa_low_hppa_sign_extend (inst & 0x1f, 5);
else
offset = extract_14 (inst);
offset = hppa_extract_14 (inst);
/* Handle code with and without frame pointers. */
if (u->Save_SP)
@ -2210,7 +1681,7 @@ hppa_frame_cache (struct frame_info *next_frame, void **this_cache)
/* ldo X(%r3),%r1 or ldo X(%r30),%r1. */
if ((inst & 0xffffc000) == 0x34610000
|| (inst & 0xffffc000) == 0x37c10000)
fp_loc = extract_14 (inst);
fp_loc = hppa_extract_14 (inst);
reg = inst_saves_fr (inst);
if (reg >= 12 && reg <= 21)
@ -2690,10 +2161,6 @@ hppa_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
/* The following gdbarch vector elements do not depend on the address
size, or in any other gdbarch element previously set. */
set_gdbarch_skip_prologue (gdbarch, hppa_skip_prologue);
set_gdbarch_skip_trampoline_code (gdbarch, hppa_skip_trampoline_code);
set_gdbarch_in_solib_call_trampoline (gdbarch, hppa_in_solib_call_trampoline);
set_gdbarch_in_solib_return_trampoline (gdbarch,
hppa_in_solib_return_trampoline);
set_gdbarch_inner_than (gdbarch, core_addr_greaterthan);
set_gdbarch_sp_regnum (gdbarch, HPPA_SP_REGNUM);
set_gdbarch_fp0_regnum (gdbarch, HPPA_FP0_REGNUM);

12
gdb/hppa-tdep.h
View File

@ -104,6 +104,8 @@ enum unwind_stub_types
IMPORT_SHLIB = 12,
};
struct unwind_table_entry *find_unwind_entry (CORE_ADDR);
/* We use the objfile->obj_private pointer for two things:
* 1. An unwind table;
*
@ -134,4 +136,14 @@ struct hppa_objfile_private
extern const struct objfile_data *hppa_objfile_priv_data;
int hppa_get_field (unsigned word, int from, int to);
int hppa_extract_5_load (unsigned int);
unsigned hppa_extract_5R_store (unsigned int);
unsigned hppa_extract_5r_store (unsigned int);
int hppa_extract_17 (unsigned int);
int hppa_extract_21 (unsigned);
int hppa_extract_14 (unsigned);
int hppa_low_sign_extend (unsigned int, unsigned int);
int hppa_sign_extend (unsigned int, unsigned int);
#endif /* HPPA_TDEP_H */