def _rebasePage(self, ctx: MachOContext, pageOffset: int,
delta: int) -> None:
locOff = pageOffset
while True:
locOff += delta
locInfo = dyld_cache_slide_pointer3(self.dyldCtx.file, locOff)
# It appears the delta encoded in the pointers are 64bit jumps...
delta = locInfo.plain.offsetToNextPointer * 8
if locInfo.auth.authenticated:
newValue = locInfo.auth.offsetFromSharedCacheBase
newValue += self.slideInfo.auth_value_add
else:
value51 = locInfo.plain.pointerValue
top8Bits = value51 & 0x0007F80000000000
bottom43Bits = value51 & 0x000007FFFFFFFFFF
newValue = (top8Bits << 13) | bottom43Bits
ctx.writeBytes(locOff, struct.pack("<Q", newValue))
if delta == 0:
break
pass
pass
def _rebasePage(self, ctx: MachOContext, pageStart: int,
pageOffset: int) -> None:
"""Process the slide info for a page.
Args:
pageStart: the file offset to the page.
pageOffset: the offset from the pageStart to the first rebase location.
"""
deltaMask = self.slideInfo.delta_mask
valueMask = ~deltaMask
valueAdd = self.slideInfo.value_add
# basically __builtin_ctzll(deltaMask) - 2;
deltaShift = "{0:b}".format(deltaMask)
deltaShift = len(deltaShift) - len(deltaShift.rstrip("0"))
deltaShift = deltaShift - 2
delta = 1
while delta != 0:
loc = pageStart + pageOffset
rawValue = self.dyldCtx.readFormat("<Q", loc)[0]
delta = (rawValue & deltaMask) >> deltaShift
newValue = rawValue & valueMask
if valueMask != 0:
newValue += valueAdd
ctx.writeBytes(loc, struct.pack("<Q", newValue))
pageOffset += delta
pass