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gumstalker-x86.c
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gumstalker-x86.c
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/*
* Copyright (C) 2009-2014 Ole André Vadla Ravnås <ole.andre.ravnas@tillitech.com>
* Copyright (C) 2010-2013 Karl Trygve Kalleberg <karltk@boblycat.org>
*
* Licence: wxWindows Library Licence, Version 3.1
*/
#define ENABLE_DEBUG 0
#include "gumstalker.h"
#include "gummetalhash.h"
#include "gumx86reader.h"
#include "gumx86writer.h"
#include "gummemory.h"
#include "gumx86relocator.h"
#include "gumspinlock.h"
#include "gumtls.h"
#include <stdlib.h>
#include <string.h>
#ifdef G_OS_WIN32
#include "backend-windows/gumwinexceptionhook.h"
#define VC_EXTRALEAN
#include <windows.h>
#include <psapi.h>
#include <tchar.h>
#endif
#define GUM_CODE_ALIGNMENT 8
#define GUM_DATA_ALIGNMENT 8
#define GUM_CODE_SLAB_SIZE_IN_PAGES 1024
#define GUM_EXEC_BLOCK_MIN_SIZE 1024
#define GUM_RED_ZONE_SIZE 128
typedef struct _GumInfectContext GumInfectContext;
typedef struct _GumDisinfectContext GumDisinfectContext;
typedef struct _GumCallProbe GumCallProbe;
typedef struct _GumSlab GumSlab;
typedef struct _GumExecFrame GumExecFrame;
typedef struct _GumExecCtx GumExecCtx;
typedef struct _GumExecBlock GumExecBlock;
typedef guint GumPrologType;
typedef guint GumCodeContext;
typedef struct _GumGeneratorContext GumGeneratorContext;
typedef struct _GumInstruction GumInstruction;
typedef struct _GumBranchTarget GumBranchTarget;
typedef guint GumVirtualizationRequirements;
struct _GumStalkerPrivate
{
guint page_size;
GMutex mutex;
GSList * contexts;
GumTlsKey exec_ctx;
GArray * exclusions;
gint trust_threshold;
volatile gboolean any_probes_attached;
volatile gint last_probe_id;
GumSpinlock probe_lock;
GHashTable * probe_target_by_id;
GHashTable * probe_array_by_address;
#ifdef G_OS_WIN32
gpointer user32_start, user32_end;
gpointer ki_user_callback_dispatcher_impl;
#endif
};
struct _GumInfectContext
{
GumStalker * stalker;
GumEventSink * sink;
};
struct _GumDisinfectContext
{
GumStalker * stalker;
GumExecCtx * exec_ctx;
gboolean success;
};
struct _GumCallProbe
{
GumProbeId id;
GumCallProbeCallback callback;
gpointer user_data;
GDestroyNotify user_notify;
};
struct _GumSlab
{
guint8 * data;
guint offset;
guint size;
GumSlab * next;
};
struct _GumExecFrame
{
gpointer real_address;
gpointer code_address;
};
enum _GumExecCtxState
{
GUM_EXEC_CTX_ACTIVE,
GUM_EXEC_CTX_UNFOLLOW_PENDING,
GUM_EXEC_CTX_DESTROY_PENDING
};
struct _GumExecCtx
{
volatile guint state;
volatile gboolean invalidate_pending;
GumStalker * stalker;
GumThreadId thread_id;
GumX86Writer code_writer;
GumX86Relocator relocator;
GumEventSink * sink;
GumEventType sink_mask;
gpointer sink_process_impl; /* cached */
GumEvent tmp_event;
gboolean unfollow_called_while_still_following;
GumExecBlock * current_block;
GumExecFrame * current_frame;
GumExecFrame * first_frame;
GumExecFrame * frames;
gpointer resume_at;
gpointer return_at;
gpointer app_stack;
gpointer thunks;
gpointer infect_thunk;
GumSlab * code_slab;
GumSlab first_code_slab;
GumMetalHashTable * mappings;
};
struct _GumExecBlock
{
GumExecCtx * ctx;
GumSlab * slab;
guint8 * real_begin;
guint8 * real_end;
guint8 * real_snapshot;
guint8 * code_begin;
guint8 * code_end;
guint8 state;
gint recycle_count;
gboolean has_call_to_excluded_range;
#ifdef G_OS_WIN32
DWORD previous_dr0;
DWORD previous_dr1;
DWORD previous_dr2;
DWORD previous_dr7;
#endif
};
enum _GumExecState
{
GUM_EXEC_NORMAL,
GUM_EXEC_SINGLE_STEPPING_ON_CALL,
GUM_EXEC_SINGLE_STEPPING_THROUGH_CALL
};
enum _GumPrologType
{
GUM_PROLOG_NONE,
GUM_PROLOG_MINIMAL,
GUM_PROLOG_FULL
};
enum _GumCodeContext
{
GUM_CODE_INTERRUPTIBLE,
GUM_CODE_UNINTERRUPTIBLE
};
struct _GumGeneratorContext
{
GumInstruction * instruction;
GumX86Relocator * relocator;
GumX86Writer * code_writer;
gpointer continuation_real_address;
GumPrologType opened_prolog;
guint state_preserve_stack_offset;
guint state_preserve_stack_gap;
guint accumulated_stack_delta;
};
struct _GumInstruction
{
cs_insn * ci;
guint8 * begin;
guint8 * end;
};
struct _GumBranchTarget
{
gpointer origin_ip;
gpointer absolute_address;
gssize relative_offset;
gboolean is_indirect;
uint8_t pfx_seg;
x86_reg base;
x86_reg index;
guint8 scale;
};
enum _GumVirtualizationRequirements
{
GUM_REQUIRE_NOTHING = 0,
GUM_REQUIRE_RELOCATION = 1 << 0,
GUM_REQUIRE_SINGLE_STEP = 1 << 1
};
#define GUM_STALKER_LOCK(o) g_mutex_lock (&(o)->priv->mutex)
#define GUM_STALKER_UNLOCK(o) g_mutex_unlock (&(o)->priv->mutex)
#if GLIB_SIZEOF_VOID_P == 4
#define STATE_PRESERVE_TOPMOST_REGISTER_INDEX (3)
#else
#define STATE_PRESERVE_TOPMOST_REGISTER_INDEX (9)
#endif
#define GUM_THUNK_ARGLIST_STACK_RESERVE 64 /* x64 ABI compatibility */
static void gum_stalker_finalize (GObject * object);
G_GNUC_INTERNAL void _gum_stalker_do_follow_me (GumStalker * self,
GumEventSink * sink, volatile gpointer * ret_addr_ptr);
static void gum_stalker_infect (GumThreadId thread_id,
GumCpuContext * cpu_context, gpointer user_data);
static void gum_stalker_disinfect (GumThreadId thread_id,
GumCpuContext * cpu_context, gpointer user_data);
static void gum_stalker_free_probe_array (gpointer data);
static GumExecCtx * gum_stalker_create_exec_ctx (GumStalker * self,
GumThreadId thread_id, GumEventSink * sink);
static GumExecCtx * gum_stalker_get_exec_ctx (GumStalker * self);
static void gum_stalker_invalidate_caches (GumStalker * self);
static void gum_exec_ctx_free (GumExecCtx * ctx);
static void gum_exec_ctx_unfollow (GumExecCtx * ctx, gpointer resume_at);
static gboolean gum_exec_ctx_has_executed (GumExecCtx * ctx);
static gpointer GUM_THUNK gum_exec_ctx_replace_current_block_with (
GumExecCtx * ctx, gpointer start_address);
static void gum_exec_ctx_create_thunks (GumExecCtx * ctx);
static void gum_exec_ctx_destroy_thunks (GumExecCtx * ctx);
static GumExecBlock * gum_exec_ctx_obtain_block_for (GumExecCtx * ctx,
gpointer real_address, gpointer * code_address);
static void gum_exec_ctx_write_prolog (GumExecCtx * ctx, GumPrologType type,
gpointer ip, GumX86Writer * cw);
static void gum_exec_ctx_write_epilog (GumExecCtx * ctx, GumPrologType type,
GumX86Writer * cw);
static void gum_exec_ctx_write_push_branch_target_address (GumExecCtx * ctx,
const GumBranchTarget * target, GumGeneratorContext * gc);
static void gum_exec_ctx_load_real_register_into (GumExecCtx * ctx,
GumCpuReg target_register, GumCpuReg source_register,
gpointer ip, GumGeneratorContext * gc);
static GumExecBlock * gum_exec_block_new (GumExecCtx * ctx);
static GumExecBlock * gum_exec_block_obtain (GumExecCtx * ctx,
gpointer real_address, gpointer * code_address);
static gboolean gum_exec_block_is_full (GumExecBlock * block);
static void gum_exec_block_commit (GumExecBlock * block);
static void gum_exec_block_backpatch_call (GumExecBlock * block,
gpointer code_start, GumPrologType opened_prolog, gpointer target_address,
gpointer ret_real_address, gpointer ret_code_address);
static void gum_exec_block_backpatch_jmp (GumExecBlock * block,
gpointer code_start, GumPrologType opened_prolog, gpointer target_address);
static void gum_exec_block_backpatch_ret (GumExecBlock * block,
gpointer code_start, gpointer target_address);
static GumVirtualizationRequirements gum_exec_block_virtualize_branch_insn (
GumExecBlock * block, GumGeneratorContext * gc);
static GumVirtualizationRequirements gum_exec_block_virtualize_ret_insn (
GumExecBlock * block, GumGeneratorContext * gc);
static GumVirtualizationRequirements gum_exec_block_virtualize_sysenter_insn (
GumExecBlock * block, GumGeneratorContext * gc);
static void gum_exec_block_write_call_invoke_code (GumExecBlock * block,
const GumBranchTarget * target, GumGeneratorContext * gc);
static void gum_exec_block_write_jmp_transfer_code (GumExecBlock * block,
const GumBranchTarget * target, GumGeneratorContext * gc);
static void gum_exec_block_write_ret_transfer_code (GumExecBlock * block,
GumGeneratorContext * gc);
static void gum_exec_block_write_single_step_transfer_code (
GumExecBlock * block, GumGeneratorContext * gc);
static void gum_exec_block_write_call_event_code (GumExecBlock * block,
const GumBranchTarget * target, GumGeneratorContext * gc,
GumCodeContext cc);
static void gum_exec_block_write_ret_event_code (GumExecBlock * block,
GumGeneratorContext * gc, GumCodeContext cc);
static void gum_exec_block_write_exec_event_code (GumExecBlock * block,
GumGeneratorContext * gc, GumCodeContext cc);
static void gum_exec_block_write_event_init_code (GumExecBlock * block,
GumEventType type, GumGeneratorContext * gc);
static void gum_exec_block_write_event_submit_code (GumExecBlock * block,
GumGeneratorContext * gc, GumCodeContext cc);
static void gum_exec_block_write_call_probe_code (GumExecBlock * block,
const GumBranchTarget * target, GumGeneratorContext * gc);
static void gum_exec_block_open_prolog (GumExecBlock * block,
GumPrologType type, GumGeneratorContext * gc);
static void gum_exec_block_close_prolog (GumExecBlock * block,
GumGeneratorContext * gc);
static void gum_write_segment_prefix (uint8_t segment, GumX86Writer * cw);
static GumCpuReg gum_cpu_meta_reg_from_real_reg (GumCpuReg reg);
static GumCpuReg gum_cpu_reg_from_capstone (x86_reg reg);
static void gum_tls_key_set (GumTlsKey key, gpointer data);
#ifdef G_OS_WIN32
static gboolean gum_stalker_handle_exception (
EXCEPTION_RECORD * exception_record, CONTEXT * context,
gpointer user_data);
#endif
G_DEFINE_TYPE (GumStalker, gum_stalker, G_TYPE_OBJECT);
static void
gum_stalker_class_init (GumStalkerClass * klass)
{
GObjectClass * object_class = G_OBJECT_CLASS (klass);
g_type_class_add_private (klass, sizeof (GumStalkerPrivate));
object_class->finalize = gum_stalker_finalize;
}
static void
gum_stalker_init (GumStalker * self)
{
GumStalkerPrivate * priv;
self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self,
GUM_TYPE_STALKER, GumStalkerPrivate);
priv = self->priv;
priv->exclusions = g_array_new (FALSE, FALSE, sizeof (GumMemoryRange));
priv->trust_threshold = 1;
gum_spinlock_init (&priv->probe_lock);
priv->probe_target_by_id =
g_hash_table_new_full (NULL, NULL, NULL, NULL);
priv->probe_array_by_address =
g_hash_table_new_full (NULL, NULL, NULL, gum_stalker_free_probe_array);
#if defined (G_OS_WIN32) && GLIB_SIZEOF_VOID_P == 4
gum_win_exception_hook_add (gum_stalker_handle_exception, self);
{
HMODULE ntmod, usermod;
MODULEINFO mi;
BOOL success;
gboolean found_user32_code = FALSE;
guint8 * p;
ntmod = GetModuleHandle (_T ("ntdll.dll"));
usermod = GetModuleHandle (_T ("user32.dll"));
g_assert (ntmod != NULL && usermod != NULL);
success = GetModuleInformation (GetCurrentProcess (), usermod,
&mi, sizeof (mi));
g_assert (success);
priv->user32_start = mi.lpBaseOfDll;
priv->user32_end = (guint8 *) mi.lpBaseOfDll + mi.SizeOfImage;
for (p = (guint8 *) priv->user32_start; p < (guint8 *) priv->user32_end;)
{
MEMORY_BASIC_INFORMATION mbi;
success = VirtualQuery (p, &mbi, sizeof (mbi)) == sizeof (mbi);
g_assert (success);
if (mbi.Protect == PAGE_EXECUTE_READ ||
mbi.Protect == PAGE_EXECUTE_READWRITE ||
mbi.Protect == PAGE_EXECUTE_WRITECOPY)
{
priv->user32_start = mbi.BaseAddress;
priv->user32_end = (guint8 *) mbi.BaseAddress + mbi.RegionSize;
found_user32_code = TRUE;
}
p = (guint8 *) mbi.BaseAddress + mbi.RegionSize;
}
g_assert (found_user32_code);
priv->ki_user_callback_dispatcher_impl = GUM_FUNCPTR_TO_POINTER (
GetProcAddress (ntmod, "KiUserCallbackDispatcher"));
g_assert (priv->ki_user_callback_dispatcher_impl != NULL);
}
#endif
priv->page_size = gum_query_page_size ();
g_mutex_init (&priv->mutex);
priv->contexts = NULL;
GUM_TLS_KEY_INIT (&priv->exec_ctx);
}
static void
gum_stalker_finalize (GObject * object)
{
GumStalker * self = GUM_STALKER (object);
GumStalkerPrivate * priv = self->priv;
#if defined (G_OS_WIN32) && GLIB_SIZEOF_VOID_P == 4
gum_win_exception_hook_remove (gum_stalker_handle_exception, self);
#endif
g_hash_table_unref (priv->probe_array_by_address);
g_hash_table_unref (priv->probe_target_by_id);
gum_spinlock_free (&priv->probe_lock);
g_array_free (priv->exclusions, TRUE);
g_assert (priv->contexts == NULL);
g_mutex_clear (&priv->mutex);
G_OBJECT_CLASS (gum_stalker_parent_class)->finalize (object);
}
GumStalker *
gum_stalker_new (void)
{
return GUM_STALKER (g_object_new (GUM_TYPE_STALKER, NULL));
}
void
gum_stalker_exclude (GumStalker * self,
const GumMemoryRange * range)
{
g_array_append_val (self->priv->exclusions, *range);
}
gint
gum_stalker_get_trust_threshold (GumStalker * self)
{
return self->priv->trust_threshold;
}
void
gum_stalker_set_trust_threshold (GumStalker * self,
gint trust_threshold)
{
self->priv->trust_threshold = trust_threshold;
}
void
gum_stalker_stop (GumStalker * self)
{
GumStalkerPrivate * priv = self->priv;
gboolean rescan_needed;
GSList * cur;
gum_spinlock_acquire (&priv->probe_lock);
g_hash_table_remove_all (priv->probe_target_by_id);
g_hash_table_remove_all (priv->probe_array_by_address);
priv->any_probes_attached = FALSE;
gum_spinlock_release (&priv->probe_lock);
GUM_STALKER_LOCK (self);
do
{
rescan_needed = FALSE;
for (cur = priv->contexts; cur != NULL; cur = cur->next)
{
GumExecCtx * ctx = (GumExecCtx *) cur->data;
if (ctx->state == GUM_EXEC_CTX_ACTIVE)
{
GumThreadId thread_id = ctx->thread_id;
GUM_STALKER_UNLOCK (self);
gum_stalker_unfollow (self, thread_id);
GUM_STALKER_LOCK (self);
rescan_needed = TRUE;
break;
}
}
}
while (rescan_needed);
GUM_STALKER_UNLOCK (self);
gum_stalker_garbage_collect (self);
}
gboolean
gum_stalker_garbage_collect (GumStalker * self)
{
GSList * keep = NULL, * cur;
gboolean pending_garbage;
GUM_STALKER_LOCK (self);
for (cur = self->priv->contexts; cur != NULL; cur = cur->next)
{
GumExecCtx * ctx = (GumExecCtx *) cur->data;
if (ctx->state == GUM_EXEC_CTX_DESTROY_PENDING)
gum_exec_ctx_free (ctx);
else
keep = g_slist_prepend (keep, ctx);
}
g_slist_free (self->priv->contexts);
self->priv->contexts = keep;
pending_garbage = keep != NULL;
GUM_STALKER_UNLOCK (self);
return pending_garbage;
}
#ifdef _MSC_VER
#define RETURN_ADDRESS_POINTER_FROM_FIRST_ARGUMENT(arg) \
((gpointer *) ((volatile guint8 *) &arg - sizeof (gpointer)))
void
gum_stalker_follow_me (GumStalker * self,
GumEventSink * sink)
{
volatile gpointer * ret_addr_ptr;
ret_addr_ptr = RETURN_ADDRESS_POINTER_FROM_FIRST_ARGUMENT (self);
_gum_stalker_do_follow_me (self, sink, ret_addr_ptr);
}
#endif
void
_gum_stalker_do_follow_me (GumStalker * self,
GumEventSink * sink,
volatile gpointer * ret_addr_ptr)
{
GumExecCtx * ctx;
gpointer code_address;
ctx = gum_stalker_create_exec_ctx (self,
gum_process_get_current_thread_id (), sink);
GUM_TLS_KEY_SET_VALUE (self->priv->exec_ctx, ctx);
ctx->current_block = gum_exec_ctx_obtain_block_for (ctx, *ret_addr_ptr,
&code_address);
*ret_addr_ptr = code_address;
gum_event_sink_start (sink);
}
void
gum_stalker_unfollow_me (GumStalker * self)
{
GumExecCtx * ctx;
ctx = gum_stalker_get_exec_ctx (self);
g_assert (ctx != NULL);
gum_event_sink_stop (ctx->sink);
if (ctx->current_block != NULL &&
ctx->current_block->has_call_to_excluded_range)
{
ctx->state = GUM_EXEC_CTX_UNFOLLOW_PENDING;
}
else
{
g_assert (ctx->unfollow_called_while_still_following);
GUM_TLS_KEY_SET_VALUE (self->priv->exec_ctx, NULL);
GUM_STALKER_LOCK (self);
self->priv->contexts = g_slist_remove (self->priv->contexts, ctx);
GUM_STALKER_UNLOCK (self);
gum_exec_ctx_free (ctx);
}
}
gboolean
gum_stalker_is_following_me (GumStalker * self)
{
return gum_stalker_get_exec_ctx (self) != NULL;
}
void
gum_stalker_follow (GumStalker * self,
GumThreadId thread_id,
GumEventSink * sink)
{
if (thread_id == gum_process_get_current_thread_id ())
{
gum_stalker_follow_me (self, sink);
}
else
{
GumInfectContext ctx;
ctx.stalker = self;
ctx.sink = sink;
gum_process_modify_thread (thread_id, gum_stalker_infect, &ctx);
}
}
void
gum_stalker_unfollow (GumStalker * self,
GumThreadId thread_id)
{
if (thread_id == gum_process_get_current_thread_id ())
{
gum_stalker_unfollow_me (self);
}
else
{
GSList * cur;
GUM_STALKER_LOCK (self);
for (cur = self->priv->contexts; cur != NULL; cur = cur->next)
{
GumExecCtx * ctx = (GumExecCtx *) cur->data;
if (ctx->thread_id == thread_id && ctx->state == GUM_EXEC_CTX_ACTIVE)
{
gum_event_sink_stop (ctx->sink);
if (gum_exec_ctx_has_executed (ctx))
{
ctx->state = GUM_EXEC_CTX_UNFOLLOW_PENDING;
}
else
{
GumDisinfectContext dc;
dc.stalker = self;
dc.exec_ctx = ctx;
dc.success = FALSE;
gum_process_modify_thread (thread_id, gum_stalker_disinfect, &dc);
if (!dc.success)
ctx->state = GUM_EXEC_CTX_UNFOLLOW_PENDING;
}
break;
}
}
GUM_STALKER_UNLOCK (self);
}
}
static void
gum_stalker_infect (GumThreadId thread_id,
GumCpuContext * cpu_context,
gpointer user_data)
{
GumInfectContext * infect_context = (GumInfectContext *) user_data;
GumStalker * self = infect_context->stalker;
GumExecCtx * ctx;
gpointer code_address;
GumX86Writer cw;
#if GLIB_SIZEOF_VOID_P == 4
guint align_correction = 8;
#else
guint align_correction = 0;
#endif
ctx = gum_stalker_create_exec_ctx (self, thread_id, infect_context->sink);
ctx->current_block = gum_exec_ctx_obtain_block_for (ctx,
GSIZE_TO_POINTER (GUM_CPU_CONTEXT_XIP (cpu_context)), &code_address);
GUM_CPU_CONTEXT_XIP (cpu_context) = GPOINTER_TO_SIZE (ctx->infect_thunk);
gum_x86_writer_init (&cw, ctx->infect_thunk);
gum_exec_ctx_write_prolog (ctx, GUM_PROLOG_MINIMAL,
ctx->current_block->real_begin, &cw);
gum_x86_writer_put_sub_reg_imm (&cw, GUM_REG_XSP, align_correction);
gum_x86_writer_put_call_with_arguments (&cw,
GUM_FUNCPTR_TO_POINTER (gum_tls_key_set), 2,
GUM_ARG_POINTER, self->priv->exec_ctx,
GUM_ARG_POINTER, ctx);
gum_x86_writer_put_add_reg_imm (&cw, GUM_REG_XSP, align_correction);
gum_exec_ctx_write_epilog (ctx, GUM_PROLOG_MINIMAL, &cw);
gum_x86_writer_put_jmp (&cw, code_address);
gum_x86_writer_free (&cw);
gum_event_sink_start (infect_context->sink);
}
static void
gum_stalker_disinfect (GumThreadId thread_id,
GumCpuContext * cpu_context,
gpointer user_data)
{
GumDisinfectContext * disinfect_context = (GumDisinfectContext *) user_data;
GumStalker * self = disinfect_context->stalker;
GumExecCtx * ctx = disinfect_context->exec_ctx;
gboolean infection_not_active_yet;
(void) thread_id;
infection_not_active_yet =
GUM_CPU_CONTEXT_XIP (cpu_context) == GPOINTER_TO_SIZE (ctx->infect_thunk);
if (infection_not_active_yet)
{
GUM_CPU_CONTEXT_XIP (cpu_context) =
GPOINTER_TO_SIZE (ctx->current_block->real_begin);
self->priv->contexts = g_slist_remove (self->priv->contexts, ctx);
gum_exec_ctx_free (ctx);
disinfect_context->success = TRUE;
}
}
GumProbeId
gum_stalker_add_call_probe (GumStalker * self,
gpointer target_address,
GumCallProbeCallback callback,
gpointer data,
GDestroyNotify notify)
{
GumStalkerPrivate * priv = self->priv;
GumCallProbe probe;
GArray * probes;
probe.id = g_atomic_int_add (&priv->last_probe_id, 1) + 1;
probe.callback = callback;
probe.user_data = data;
probe.user_notify = notify;
gum_spinlock_acquire (&priv->probe_lock);
g_hash_table_insert (priv->probe_target_by_id, GSIZE_TO_POINTER (probe.id),
target_address);
probes = (GArray *)
g_hash_table_lookup (priv->probe_array_by_address, target_address);
if (probes == NULL)
{
probes = g_array_sized_new (FALSE, FALSE, sizeof (GumCallProbe), 4);
g_hash_table_insert (priv->probe_array_by_address, target_address, probes);
}
g_array_append_val (probes, probe);
priv->any_probes_attached = TRUE;
gum_spinlock_release (&priv->probe_lock);
gum_stalker_invalidate_caches (self);
return probe.id;
}
void
gum_stalker_remove_call_probe (GumStalker * self,
GumProbeId id)
{
GumStalkerPrivate * priv = self->priv;
gpointer target_address;
gum_spinlock_acquire (&priv->probe_lock);
target_address =
g_hash_table_lookup (priv->probe_target_by_id, GSIZE_TO_POINTER (id));
if (target_address != NULL)
{
GArray * probes;
gint match_index = -1;
guint i;
GumCallProbe * probe;
g_hash_table_remove (priv->probe_target_by_id, GSIZE_TO_POINTER (id));
probes = (GArray *)
g_hash_table_lookup (priv->probe_array_by_address, target_address);
g_assert (probes != NULL);
for (i = 0; i != probes->len; i++)
{
if (g_array_index (probes, GumCallProbe, i).id == id)
{
match_index = i;
break;
}
}
g_assert_cmpint (match_index, !=, -1);
probe = &g_array_index (probes, GumCallProbe, match_index);
if (probe->user_notify != NULL)
probe->user_notify (probe->user_data);
g_array_remove_index (probes, match_index);
if (probes->len == 0)
g_hash_table_remove (priv->probe_array_by_address, target_address);
priv->any_probes_attached =
g_hash_table_size (priv->probe_array_by_address) != 0;
}
gum_spinlock_release (&priv->probe_lock);
gum_stalker_invalidate_caches (self);
}
static void
gum_stalker_free_probe_array (gpointer data)
{
GArray * probes = (GArray *) data;
guint i;
for (i = 0; i != probes->len; i++)
{
GumCallProbe * probe = &g_array_index (probes, GumCallProbe, i);
if (probe->user_notify != NULL)
probe->user_notify (probe->user_data);
}
g_array_free (probes, TRUE);
}
static GumExecCtx *
gum_stalker_create_exec_ctx (GumStalker * self,
GumThreadId thread_id,
GumEventSink * sink)
{
GumStalkerPrivate * priv = self->priv;
guint base_size;
GumExecCtx * ctx;
base_size = sizeof (GumExecCtx) / priv->page_size;
if (sizeof (GumExecCtx) % priv->page_size != 0)
base_size++;
ctx = (GumExecCtx *)
gum_alloc_n_pages (base_size + GUM_CODE_SLAB_SIZE_IN_PAGES + 1,
GUM_PAGE_RWX);
ctx->state = GUM_EXEC_CTX_ACTIVE;
ctx->invalidate_pending = FALSE;
ctx->code_slab = &ctx->first_code_slab;
ctx->first_code_slab.data = ((guint8 *) ctx) + (base_size * priv->page_size);
ctx->first_code_slab.offset = 0;
ctx->first_code_slab.size = GUM_CODE_SLAB_SIZE_IN_PAGES * priv->page_size;
ctx->first_code_slab.next = NULL;
ctx->frames = (GumExecFrame *)
(ctx->code_slab->data + ctx->code_slab->size);
ctx->first_frame = (GumExecFrame *) (ctx->code_slab->data +
ctx->code_slab->size + priv->page_size - sizeof (GumExecFrame));
ctx->current_frame = ctx->first_frame;
ctx->mappings = gum_metal_hash_table_new (NULL, NULL);
ctx->resume_at = NULL;
ctx->return_at = NULL;
ctx->app_stack = NULL;
ctx->stalker = g_object_ref (self);
ctx->thread_id = thread_id;
gum_x86_writer_init (&ctx->code_writer, NULL);
gum_x86_relocator_init (&ctx->relocator, NULL, &ctx->code_writer);
ctx->sink = (GumEventSink *) g_object_ref (sink);
ctx->sink_mask = gum_event_sink_query_mask (sink);
ctx->sink_process_impl = GUM_FUNCPTR_TO_POINTER (
GUM_EVENT_SINK_GET_INTERFACE (sink)->process);
gum_exec_ctx_create_thunks (ctx);
GUM_STALKER_LOCK (self);
self->priv->contexts = g_slist_prepend (self->priv->contexts, ctx);
GUM_STALKER_UNLOCK (self);
return ctx;
}
static GumExecCtx *
gum_stalker_get_exec_ctx (GumStalker * self)
{
return (GumExecCtx *) GUM_TLS_KEY_GET_VALUE (self->priv->exec_ctx);
}
static void
gum_stalker_invalidate_caches (GumStalker * self)
{
GSList * cur;
GUM_STALKER_LOCK (self);
for (cur = self->priv->contexts; cur != NULL; cur = cur->next)
{
GumExecCtx * ctx = (GumExecCtx *) cur->data;
ctx->invalidate_pending = TRUE;
}
GUM_STALKER_UNLOCK (self);
}
static void
gum_exec_ctx_free (GumExecCtx * ctx)
{
GumSlab * slab;
gum_metal_hash_table_unref (ctx->mappings);
slab = ctx->code_slab;
while (slab != &ctx->first_code_slab)
{
GumSlab * next = slab->next;
gum_free_pages (slab);
slab = next;
}
gum_exec_ctx_destroy_thunks (ctx);
g_object_unref (ctx->sink);
gum_x86_relocator_free (&ctx->relocator);
gum_x86_writer_free (&ctx->code_writer);
g_object_unref (ctx->stalker);
gum_free_pages (ctx);
}
static void
gum_exec_ctx_unfollow (GumExecCtx * ctx,
gpointer resume_at)
{
ctx->resume_at = resume_at;
GUM_TLS_KEY_SET_VALUE (ctx->stalker->priv->exec_ctx, NULL);
ctx->current_block = NULL;
ctx->state = GUM_EXEC_CTX_DESTROY_PENDING;
}
static gboolean
gum_exec_ctx_has_executed (GumExecCtx * ctx)
{
return ctx->resume_at != NULL;
}
static gpointer GUM_THUNK
gum_exec_ctx_replace_current_block_with (GumExecCtx * ctx,
gpointer start_address)
{
if (ctx->invalidate_pending)
{
gum_metal_hash_table_remove_all (ctx->mappings);
ctx->invalidate_pending = FALSE;
}
if (start_address == gum_stalker_unfollow_me)
{
ctx->unfollow_called_while_still_following = TRUE;
ctx->current_block = NULL;
ctx->resume_at = start_address;
}
else if (ctx->state == GUM_EXEC_CTX_UNFOLLOW_PENDING)
{
gum_exec_ctx_unfollow (ctx, start_address);
}
else
{
ctx->current_block = gum_exec_ctx_obtain_block_for (ctx, start_address,
&ctx->resume_at);