libsframe: fix issue finding FRE in PCMASK type SFrame FDEs
SFrame FDEs of type SFRAME_FDE_TYPE_PCMASK are used for repetitive code
patterns, e.g., pltN entries. For SFrame FDEs of type
SFRAME_FDE_TYPE_PCMASK, sframe_fre_check_range_p erroneously tested the
given PC instead of the masked PC offset from function start address.
Therefore it only worked correctly by chance, e.g., if the function start
address was aligned on the repetition block size.
For regular SFrame FDEs the PC offset from function start address must
be within a SFrame FRE's start IP offset and end IP offset. For SFrame
FDEs of type SFRAME_FDE_TYPE_PCMASK, the masked PC offset must be within
that range.
SFrame FRE start/end IP offsets are relative to the SFrame FDE function
start address. For regular SFrame FDEs, the PC offset from function
start address must be within a SFrame FRE's start IP offset and end IP
offset. For SFRAME_FDE_TYPE_PCMASK type FDEs, the masked PC offset must
be within that range.
Exercise the testcase for a variety of placements; without the fix some
of these tests will fail. Also, make the testcase itself easier to
follow by adding appropriate vars where applicable.
libsframe/
* sframe.c (sframe_fre_check_range_p): Fix logic for
SFRAME_FDE_TYPE_PCMASK type FDE.
libsframe/testsuite/
* libsframe.find/plt-findfre-1.c: Adjust the test for a variety
of placements of .sframe and .plt.
Co-Authored-by: Jens Remus <jremus@linux.ibm.com>
2 files changed
