void
mono_arch_patch_callsite (guint8 *method_start, guint8 *orig_code, guint8 *addr)
{
guint8 *code;
guint8 buf [8];
gboolean can_write = mono_breakpoint_clean_code (method_start, orig_code, 8, buf, sizeof (buf));
code = buf + 8;
/* go to the start of the call instruction
*
* address_byte = (m << 6) | (o << 3) | reg
* call opcode: 0xff address_byte displacement
* 0xff m=1,o=2 imm8
* 0xff m=2,o=2 imm32
*/
code -= 6;
orig_code -= 6;
if (code [1] == 0xe8) {
if (can_write) {
mono_atomic_xchg_i32 ((gint32*)(orig_code + 2), (guint)addr - ((guint)orig_code + 1) - 5);
/* Tell valgrind to recompile the patched code */
VALGRIND_DISCARD_TRANSLATIONS (orig_code + 2, 4);
}
} else if (code [1] == 0xe9) {
/* A PLT entry: jmp <DISP> */
if (can_write)
mono_atomic_xchg_i32 ((gint32*)(orig_code + 2), (guint)addr - ((guint)orig_code + 1) - 5);
} else {
printf ("Invalid trampoline sequence: %x %x %x %x %x %x %x\n", code [0], code [1], code [2], code [3],
code [4], code [5], code [6]);
g_assert_not_reached ();
}
}
static inline void
leave_alertable_wait (MonoThreadInfo *info)
{
// Clear any previous flags. Thread is exiting alertable wait state, and info around pending interrupt/abort APC's
// can now be discarded as well, thread is out of wait operation and can proceed it's execution.
mono_atomic_xchg_i32 (&info->thread_wait_info, THREAD_WAIT_INFO_CLEARED);
}
static inline void
enter_alertable_wait (MonoThreadInfo *info)
{
// Clear any previous flags. Set alertable wait flag.
mono_atomic_xchg_i32 (&info->thread_wait_info, THREAD_WAIT_INFO_ALERTABLE_WAIT_SLOT);
}