#include "sparc-tdep.h"
+struct regset;
+
/* This file implements the The SPARC 32-bit ABI as defined by the
section "Low-Level System Information" of the SPARC Compliance
Definition (SCD) 2.4.1, which is the 32-bit System V psABI for
unsigned long insn;
int i;
- read_memory (pc, buf, sizeof (buf));
+ /* If we can't read the instruction at PC, return zero. */
+ if (target_read_memory (pc, buf, sizeof (buf)))
+ return 0;
insn = 0;
for (i = 0; i < sizeof (buf); i++)
return insn;
}
\f
+
+/* OpenBSD/sparc includes StackGhost, which according to the author's
+ website http://stackghost.cerias.purdue.edu "... transparently and
+ automatically protects applications' stack frames; more
+ specifically, it guards the return pointers. The protection
+ mechanisms require no application source or binary modification and
+ imposes only a negligible performance penalty."
+
+ The same website provides the following description of how
+ StackGhost works:
+
+ "StackGhost interfaces with the kernel trap handler that would
+ normally write out registers to the stack and the handler that
+ would read them back in. By XORing a cookie into the
+ return-address saved in the user stack when it is actually written
+ to the stack, and then XOR it out when the return-address is pulled
+ from the stack, StackGhost can cause attacker corrupted return
+ pointers to behave in a manner the attacker cannot predict.
+ StackGhost can also use several unused bits in the return pointer
+ to detect a smashed return pointer and abort the process."
+
+ For GDB this means that whenever we're reading %i7 from a stack
+ frame's window save area, we'll have to XOR the cookie.
+
+ More information on StackGuard can be found on in:
+
+ Mike Frantzen and Mike Shuey. "StackGhost: Hardware Facilitated
+ Stack Protection." 2001. Published in USENIX Security Symposium
+ '01. */
+
+/* Fetch StackGhost Per-Process XOR cookie. */
+
+ULONGEST
+sparc_fetch_wcookie (void)
+{
+ struct target_ops *ops = ¤t_target;
+ char buf[8];
+ int len;
+
+ len = target_read_partial (ops, TARGET_OBJECT_WCOOKIE, NULL, buf, 0, 8);
+ if (len == -1)
+ return 0;
+
+ /* We should have either an 32-bit or an 64-bit cookie. */
+ gdb_assert (len == 4 || len == 8);
+
+ return extract_unsigned_integer (buf, len);
+}
+\f
+
/* Return the contents if register REGNUM as an address. */
static CORE_ADDR
return;
}
+ /* Handle StackGhost. */
+ {
+ ULONGEST wcookie = sparc_fetch_wcookie ();
+
+ if (wcookie != 0 && !cache->frameless_p && regnum == SPARC_I7_REGNUM)
+ {
+ *optimizedp = 0;
+ *lvalp = not_lval;
+ *addrp = 0;
+ *realnump = -1;
+ if (valuep)
+ {
+ CORE_ADDR addr = cache->base + (regnum - SPARC_L0_REGNUM) * 4;
+ ULONGEST i7;
+
+ /* Read the value in from memory. */
+ i7 = get_frame_memory_unsigned (next_frame, addr, 4);
+ store_unsigned_integer (valuep, 4, i7 ^ wcookie);
+ }
+ return;
+ }
+ }
+
/* The previous frame's `local' and `in' registers have been saved
in the register save area. */
if (!cache->frameless_p
}
}
+static enum return_value_convention
+sparc32_return_value (struct gdbarch *gdbarch, struct type *type,
+ struct regcache *regcache, void *readbuf,
+ const void *writebuf)
+{
+ if (sparc_structure_or_union_p (type)
+ || (sparc_floating_p (type) && TYPE_LENGTH (type) == 16))
+ return RETURN_VALUE_STRUCT_CONVENTION;
+
+ if (readbuf)
+ sparc32_extract_return_value (type, regcache, readbuf);
+ if (writebuf)
+ sparc32_store_return_value (type, regcache, writebuf);
+
+ return RETURN_VALUE_REGISTER_CONVENTION;
+}
+
+#if 0
+/* NOTE: cagney/2004-01-17: For the moment disable this method. The
+ architecture and CORE-gdb will need new code (and a replacement for
+ DEPRECATED_EXTRACT_STRUCT_VALUE_ADDRESS) before this can be made to
+ work robustly. Here is a possible function signature: */
+/* NOTE: cagney/2004-01-17: So far only the 32-bit SPARC ABI has been
+ identifed as having a way to robustly recover the address of a
+ struct-convention return-value (after the function has returned).
+ For all other ABIs so far examined, the calling convention makes no
+ guarenteed that the register containing the return-value will be
+ preserved and hence that the return-value's address can be
+ recovered. */
/* Extract from REGCACHE, which contains the (raw) register state, the
address in which a function should return its structure value, as a
CORE_ADDR. */
static CORE_ADDR
-sparc_extract_struct_value_address (struct regcache *regcache)
-{
- ULONGEST addr;
-
- regcache_cooked_read_unsigned (regcache, SPARC_O0_REGNUM, &addr);
- return addr;
-}
-
-static int
-sparc32_use_struct_convention (int gcc_p, struct type *type)
+sparc32_extract_struct_value_address (struct regcache *regcache)
{
- gdb_assert (sparc_structure_or_union_p (type));
- return 1;
-}
+ ULONGEST sp;
-static int
-sparc32_return_value_on_stack (struct type *type)
-{
- gdb_assert (!sparc_structure_or_union_p (type));
- return (sparc_floating_p (type) && TYPE_LENGTH (type) == 16);
+ regcache_cooked_read_unsigned (regcache, SPARC_SP_REGNUM, &sp);
+ return read_memory_unsigned_integer (sp + 64, 4);
}
+#endif
static int
sparc32_stabs_argument_has_addr (struct gdbarch *gdbarch, struct type *type)
}
\f
+/* Return the appropriate register set for the core section identified
+ by SECT_NAME and SECT_SIZE. */
+
+const struct regset *
+sparc_regset_from_core_section (struct gdbarch *gdbarch,
+ const char *sect_name, size_t sect_size)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ if (strcmp (sect_name, ".reg") == 0 && sect_size >= tdep->sizeof_gregset)
+ return tdep->gregset;
+
+ if (strcmp (sect_name, ".reg2") == 0 && sect_size >= tdep->sizeof_fpregset)
+ return tdep->fpregset;
+
+ return NULL;
+}
+\f
+
static struct gdbarch *
sparc32_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
{
tdep->pc_regnum = SPARC32_PC_REGNUM;
tdep->npc_regnum = SPARC32_NPC_REGNUM;
+ tdep->gregset = NULL;
+ tdep->sizeof_gregset = 0;
+ tdep->fpregset = NULL;
+ tdep->sizeof_fpregset = 0;
tdep->plt_entry_size = 0;
set_gdbarch_long_double_bit (gdbarch, 128);
set_gdbarch_push_dummy_code (gdbarch, sparc32_push_dummy_code);
set_gdbarch_push_dummy_call (gdbarch, sparc32_push_dummy_call);
- set_gdbarch_extract_return_value (gdbarch, sparc32_extract_return_value);
- set_gdbarch_store_return_value (gdbarch, sparc32_store_return_value);
- set_gdbarch_extract_struct_value_address
- (gdbarch, sparc_extract_struct_value_address);
- set_gdbarch_use_struct_convention (gdbarch, sparc32_use_struct_convention);
- set_gdbarch_return_value_on_stack (gdbarch, sparc32_return_value_on_stack);
+ set_gdbarch_return_value (gdbarch, sparc32_return_value);
set_gdbarch_stabs_argument_has_addr
(gdbarch, sparc32_stabs_argument_has_addr);
set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
set_gdbarch_breakpoint_from_pc (gdbarch, sparc_breakpoint_from_pc);
- set_gdbarch_decr_pc_after_break (gdbarch, 0);
- set_gdbarch_function_start_offset (gdbarch, 0);
set_gdbarch_frame_args_skip (gdbarch, 8);
frame_unwind_append_sniffer (gdbarch, sparc32_frame_sniffer);
+ /* If we have register sets, enable the generic core file support. */
+ if (tdep->gregset)
+ set_gdbarch_regset_from_core_section (gdbarch,
+ sparc_regset_from_core_section);
+
return gdbarch;
}
\f
{
target_read_memory (sp + ((i - SPARC_L0_REGNUM) * 4),
buf + offset, 4);
+
+ /* Handle StackGhost. */
+ if (i == SPARC_I7_REGNUM)
+ {
+ ULONGEST wcookie = sparc_fetch_wcookie ();
+ ULONGEST i7 = extract_unsigned_integer (buf + offset, 4);
+
+ store_unsigned_integer (buf + offset, 4, i7 ^ wcookie);
+ }
+
regcache_raw_supply (regcache, i, buf);
}
}
if (regnum == -1 || regnum == SPARC_SP_REGNUM || regnum == i)
{
regcache_raw_collect (regcache, i, buf);
+
+ /* Handle StackGhost. */
+ if (i == SPARC_I7_REGNUM)
+ {
+ ULONGEST wcookie = sparc_fetch_wcookie ();
+ ULONGEST i7 = extract_unsigned_integer (buf + offset, 4);
+
+ store_unsigned_integer (buf + offset, 4, i7 ^ wcookie);
+ }
+
target_write_memory (sp + ((i - SPARC_L0_REGNUM) * 4),
buf + offset, 4);
}
projects / deliverable / binutils-gdb.git / blobdiff