/* GNU/Linux on ARM target support.
- Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
- Free Software Foundation, Inc.
+ Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
+ 2009 Free Software Foundation, Inc.
This file is part of GDB.
#include "arm-tdep.h"
#include "arm-linux-tdep.h"
+#include "linux-tdep.h"
#include "glibc-tdep.h"
+#include "arch-utils.h"
+#include "inferior.h"
+#include "gdbthread.h"
+#include "symfile.h"
#include "gdb_string.h"
#define ARM_EABI_SYSCALL 0xef000000
static void
-arm_linux_sigtramp_cache (struct frame_info *next_frame,
+arm_linux_sigtramp_cache (struct frame_info *this_frame,
struct trad_frame_cache *this_cache,
CORE_ADDR func, int regs_offset)
{
- CORE_ADDR sp = frame_unwind_register_unsigned (next_frame, ARM_SP_REGNUM);
+ CORE_ADDR sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM);
CORE_ADDR base = sp + regs_offset;
int i;
static void
arm_linux_sigreturn_init (const struct tramp_frame *self,
- struct frame_info *next_frame,
+ struct frame_info *this_frame,
struct trad_frame_cache *this_cache,
CORE_ADDR func)
{
- CORE_ADDR sp = frame_unwind_register_unsigned (next_frame, ARM_SP_REGNUM);
- ULONGEST uc_flags = read_memory_unsigned_integer (sp, 4);
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ CORE_ADDR sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM);
+ ULONGEST uc_flags = read_memory_unsigned_integer (sp, 4, byte_order);
if (uc_flags == ARM_NEW_SIGFRAME_MAGIC)
- arm_linux_sigtramp_cache (next_frame, this_cache, func,
+ arm_linux_sigtramp_cache (this_frame, this_cache, func,
ARM_UCONTEXT_SIGCONTEXT
+ ARM_SIGCONTEXT_R0);
else
- arm_linux_sigtramp_cache (next_frame, this_cache, func,
+ arm_linux_sigtramp_cache (this_frame, this_cache, func,
ARM_SIGCONTEXT_R0);
}
static void
arm_linux_rt_sigreturn_init (const struct tramp_frame *self,
- struct frame_info *next_frame,
+ struct frame_info *this_frame,
struct trad_frame_cache *this_cache,
CORE_ADDR func)
{
- CORE_ADDR sp = frame_unwind_register_unsigned (next_frame, ARM_SP_REGNUM);
- ULONGEST pinfo = read_memory_unsigned_integer (sp, 4);
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ CORE_ADDR sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM);
+ ULONGEST pinfo = read_memory_unsigned_integer (sp, 4, byte_order);
if (pinfo == sp + ARM_OLD_RT_SIGFRAME_SIGINFO)
- arm_linux_sigtramp_cache (next_frame, this_cache, func,
+ arm_linux_sigtramp_cache (this_frame, this_cache, func,
ARM_OLD_RT_SIGFRAME_UCONTEXT
+ ARM_UCONTEXT_SIGCONTEXT
+ ARM_SIGCONTEXT_R0);
else
- arm_linux_sigtramp_cache (next_frame, this_cache, func,
+ arm_linux_sigtramp_cache (this_frame, this_cache, func,
ARM_NEW_RT_SIGFRAME_UCONTEXT
+ ARM_UCONTEXT_SIGCONTEXT
+ ARM_SIGCONTEXT_R0);
struct regcache *regcache,
int regnum, const void *gregs_buf, size_t len)
{
+ struct gdbarch *gdbarch = get_regcache_arch (regcache);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
const gdb_byte *gregs = gregs_buf;
int regno;
CORE_ADDR reg_pc;
{
if (arm_apcs_32)
regcache_raw_supply (regcache, ARM_PS_REGNUM,
- gregs + INT_REGISTER_SIZE * ARM_CPSR_REGNUM);
+ gregs + INT_REGISTER_SIZE * ARM_CPSR_GREGNUM);
else
regcache_raw_supply (regcache, ARM_PS_REGNUM,
gregs + INT_REGISTER_SIZE * ARM_PC_REGNUM);
{
reg_pc = extract_unsigned_integer (gregs
+ INT_REGISTER_SIZE * ARM_PC_REGNUM,
- INT_REGISTER_SIZE);
- reg_pc = gdbarch_addr_bits_remove (get_regcache_arch (regcache), reg_pc);
- store_unsigned_integer (pc_buf, INT_REGISTER_SIZE, reg_pc);
+ INT_REGISTER_SIZE, byte_order);
+ reg_pc = gdbarch_addr_bits_remove (gdbarch, reg_pc);
+ store_unsigned_integer (pc_buf, INT_REGISTER_SIZE, byte_order, reg_pc);
regcache_raw_supply (regcache, ARM_PC_REGNUM, pc_buf);
}
}
{
if (arm_apcs_32)
regcache_raw_collect (regcache, ARM_PS_REGNUM,
- gregs + INT_REGISTER_SIZE * ARM_CPSR_REGNUM);
+ gregs + INT_REGISTER_SIZE * ARM_CPSR_GREGNUM);
else
regcache_raw_collect (regcache, ARM_PS_REGNUM,
gregs + INT_REGISTER_SIZE * ARM_PC_REGNUM);
/* Insert a single step breakpoint at the next executed instruction. */
-int
+static int
arm_linux_software_single_step (struct frame_info *frame)
{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct address_space *aspace = get_frame_address_space (frame);
CORE_ADDR next_pc = arm_get_next_pc (frame, get_frame_pc (frame));
/* The Linux kernel offers some user-mode helpers in a high page. We can
if (next_pc > 0xffff0000)
next_pc = get_frame_register_unsigned (frame, ARM_LR_REGNUM);
- insert_single_step_breakpoint (next_pc);
+ insert_single_step_breakpoint (gdbarch, aspace, next_pc);
return 1;
}
+/* Support for displaced stepping of Linux SVC instructions. */
+
+static void
+arm_linux_cleanup_svc (struct gdbarch *gdbarch ATTRIBUTE_UNUSED,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ CORE_ADDR from = dsc->insn_addr;
+ ULONGEST apparent_pc;
+ int within_scratch;
+
+ regcache_cooked_read_unsigned (regs, ARM_PC_REGNUM, &apparent_pc);
+
+ within_scratch = (apparent_pc >= dsc->scratch_base
+ && apparent_pc < (dsc->scratch_base
+ + DISPLACED_MODIFIED_INSNS * 4 + 4));
+
+ if (debug_displaced)
+ {
+ fprintf_unfiltered (gdb_stdlog, "displaced: PC is apparently %.8lx after "
+ "SVC step ", (unsigned long) apparent_pc);
+ if (within_scratch)
+ fprintf_unfiltered (gdb_stdlog, "(within scratch space)\n");
+ else
+ fprintf_unfiltered (gdb_stdlog, "(outside scratch space)\n");
+ }
+
+ if (within_scratch)
+ displaced_write_reg (regs, dsc, ARM_PC_REGNUM, from + 4, BRANCH_WRITE_PC);
+}
+
+static int
+arm_linux_copy_svc (struct gdbarch *gdbarch, uint32_t insn, CORE_ADDR to,
+ struct regcache *regs, struct displaced_step_closure *dsc)
+{
+ CORE_ADDR from = dsc->insn_addr;
+ struct frame_info *frame;
+ unsigned int svc_number = displaced_read_reg (regs, from, 7);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: copying Linux svc insn %.8lx\n",
+ (unsigned long) insn);
+
+ frame = get_current_frame ();
+
+ /* Is this a sigreturn or rt_sigreturn syscall? Note: these are only useful
+ for EABI. */
+ if (svc_number == 119 || svc_number == 173)
+ {
+ if (get_frame_type (frame) == SIGTRAMP_FRAME)
+ {
+ CORE_ADDR return_to;
+ struct symtab_and_line sal;
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: found "
+ "sigreturn/rt_sigreturn SVC call. PC in frame = %lx\n",
+ (unsigned long) get_frame_pc (frame));
+
+ return_to = frame_unwind_caller_pc (frame);
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: unwind pc = %lx. "
+ "Setting momentary breakpoint.\n", (unsigned long) return_to);
+
+ gdb_assert (inferior_thread ()->step_resume_breakpoint == NULL);
+
+ sal = find_pc_line (return_to, 0);
+ sal.pc = return_to;
+ sal.section = find_pc_overlay (return_to);
+ sal.explicit_pc = 1;
+
+ frame = get_prev_frame (frame);
+
+ if (frame)
+ {
+ inferior_thread ()->step_resume_breakpoint
+ = set_momentary_breakpoint (gdbarch, sal, get_frame_id (frame),
+ bp_step_resume);
+
+ /* We need to make sure we actually insert the momentary
+ breakpoint set above. */
+ insert_breakpoints ();
+ }
+ else if (debug_displaced)
+ fprintf_unfiltered (gdb_stderr, "displaced: couldn't find previous "
+ "frame to set momentary breakpoint for "
+ "sigreturn/rt_sigreturn\n");
+ }
+ else if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: sigreturn/rt_sigreturn "
+ "SVC call not in signal trampoline frame\n");
+ }
+
+ /* Preparation: If we detect sigreturn, set momentary breakpoint at resume
+ location, else nothing.
+ Insn: unmodified svc.
+ Cleanup: if pc lands in scratch space, pc <- insn_addr + 4
+ else leave pc alone. */
+
+ dsc->modinsn[0] = insn;
+
+ dsc->cleanup = &arm_linux_cleanup_svc;
+ /* Pretend we wrote to the PC, so cleanup doesn't set PC to the next
+ instruction. */
+ dsc->wrote_to_pc = 1;
+
+ return 0;
+}
+
+
+/* The following two functions implement single-stepping over calls to Linux
+ kernel helper routines, which perform e.g. atomic operations on architecture
+ variants which don't support them natively.
+
+ When this function is called, the PC will be pointing at the kernel helper
+ (at an address inaccessible to GDB), and r14 will point to the return
+ address. Displaced stepping always executes code in the copy area:
+ so, make the copy-area instruction branch back to the kernel helper (the
+ "from" address), and make r14 point to the breakpoint in the copy area. In
+ that way, we regain control once the kernel helper returns, and can clean
+ up appropriately (as if we had just returned from the kernel helper as it
+ would have been called from the non-displaced location). */
+
+static void
+cleanup_kernel_helper_return (struct gdbarch *gdbarch ATTRIBUTE_UNUSED,
+ struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ displaced_write_reg (regs, dsc, ARM_LR_REGNUM, dsc->tmp[0], CANNOT_WRITE_PC);
+ displaced_write_reg (regs, dsc, ARM_PC_REGNUM, dsc->tmp[0], BRANCH_WRITE_PC);
+}
+
+static void
+arm_catch_kernel_helper_return (struct gdbarch *gdbarch, CORE_ADDR from,
+ CORE_ADDR to, struct regcache *regs,
+ struct displaced_step_closure *dsc)
+{
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+
+ dsc->numinsns = 1;
+ dsc->insn_addr = from;
+ dsc->cleanup = &cleanup_kernel_helper_return;
+ /* Say we wrote to the PC, else cleanup will set PC to the next
+ instruction in the helper, which isn't helpful. */
+ dsc->wrote_to_pc = 1;
+
+ /* Preparation: tmp[0] <- r14
+ r14 <- <scratch space>+4
+ *(<scratch space>+8) <- from
+ Insn: ldr pc, [r14, #4]
+ Cleanup: r14 <- tmp[0], pc <- tmp[0]. */
+
+ dsc->tmp[0] = displaced_read_reg (regs, from, ARM_LR_REGNUM);
+ displaced_write_reg (regs, dsc, ARM_LR_REGNUM, (ULONGEST) to + 4,
+ CANNOT_WRITE_PC);
+ write_memory_unsigned_integer (to + 8, 4, byte_order, from);
+
+ dsc->modinsn[0] = 0xe59ef004; /* ldr pc, [lr, #4]. */
+}
+
+/* Linux-specific displaced step instruction copying function. Detects when
+ the program has stepped into a Linux kernel helper routine (which must be
+ handled as a special case), falling back to arm_displaced_step_copy_insn()
+ if it hasn't. */
+
+static struct displaced_step_closure *
+arm_linux_displaced_step_copy_insn (struct gdbarch *gdbarch,
+ CORE_ADDR from, CORE_ADDR to,
+ struct regcache *regs)
+{
+ struct displaced_step_closure *dsc
+ = xmalloc (sizeof (struct displaced_step_closure));
+
+ /* Detect when we enter an (inaccessible by GDB) Linux kernel helper, and
+ stop at the return location. */
+ if (from > 0xffff0000)
+ {
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: detected kernel helper "
+ "at %.8lx\n", (unsigned long) from);
+
+ arm_catch_kernel_helper_return (gdbarch, from, to, regs, dsc);
+ }
+ else
+ {
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ uint32_t insn = read_memory_unsigned_integer (from, 4, byte_order);
+
+ if (debug_displaced)
+ fprintf_unfiltered (gdb_stdlog, "displaced: stepping insn %.8lx "
+ "at %.8lx\n", (unsigned long) insn,
+ (unsigned long) from);
+
+ /* Override the default handling of SVC instructions. */
+ dsc->u.svc.copy_svc_os = arm_linux_copy_svc;
+
+ arm_process_displaced_insn (gdbarch, insn, from, to, regs, dsc);
+ }
+
+ arm_displaced_init_closure (gdbarch, from, to, dsc);
+
+ return dsc;
+}
+
static void
arm_linux_init_abi (struct gdbarch_info info,
struct gdbarch *gdbarch)
/* Core file support. */
set_gdbarch_regset_from_core_section (gdbarch,
arm_linux_regset_from_core_section);
+
+ set_gdbarch_get_siginfo_type (gdbarch, linux_get_siginfo_type);
+
+ /* Displaced stepping. */
+ set_gdbarch_displaced_step_copy_insn (gdbarch,
+ arm_linux_displaced_step_copy_insn);
+ set_gdbarch_displaced_step_fixup (gdbarch, arm_displaced_step_fixup);
+ set_gdbarch_displaced_step_free_closure (gdbarch,
+ simple_displaced_step_free_closure);
+ set_gdbarch_displaced_step_location (gdbarch, displaced_step_at_entry_point);
}
+/* Provide a prototype to silence -Wmissing-prototypes. */
+extern initialize_file_ftype _initialize_arm_linux_tdep;
+
void
_initialize_arm_linux_tdep (void)
{
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