Clean up and apply the fix for PR 83477. The calculation for locating

the start of the section headers has to take into account the fact
that the image_nt_header is really variable sized. It happens that
the existing calculation is correct for _most_ production binaries
produced by the Windows DDK, but if we get a binary with oddball
offsets, the PE loader could crash.

Changes from the supplied patch are:

- We don't really need to use the IMAGE_SIZEOF_NT_HEADER() macro when
  computing how much of the header to return to callers of
  pe_get_optional_header(). While it's important to take the variable
  size of the header into account in other calculations, we never
  actually look at anything outside the non-variable portion of the
  header. This saves callers from having to allocate a variable sized
  buffer off the heap (I purposely tried to avoid using malloc()
  in subr_pe.c to make it easier to compile in both the -D_KERNEL and
  !-D_KERNEL case), and since we're copying into a buffer on the
  stack, we always have to copy the same amount of data or else
  we'll trash the stack something fierce.

- We need <stddef.h> to get offsetof() in the !-D_KERNEL case.

- ndiscvt.c needs the IMAGE_FIRST_SECTION() macro too, since it does
  a little bit of section pre-processing.

PR: kern/83477

0 files changed, 0 insertions, 0 deletions