binja enforce the usage of the return value, although it was discarded

nitrogar commented 1 year ago

Version and Platform (required):

Binary Ninja Version: [e.g. 3.2.4000-dev] (if version is stable, please also test the latest development build via the "Update Channel" option)
OS: manjaro

Bug Description: while reversing windows x86 binary i noticed that, binja enforce the usage of return value as shown in the pictures below

binja_fail binja_fail_2 binja_fail3

eax was discarded but binja enforce it which corrupt the rest of the analysis.

Expected Behavior: after NOPing the function call, the analysis become correct as shown. binja_correct

Additional Information: Sorry i cant provide the binary ;)

xusheng6 commented 1 year ago

The problem is BN thinks the function memcpy uses register ebp as its return value, which is wrong. Can you try unchekcing the ebp checkbox in the Cloberred Registers list in the Edit Function Properties dialog of the memcpy function?

nitrogar commented 1 year ago

thanks, after removing ebp from the clobbered registers the analysis was corrected.

Vector35 / binaryninja-api

binja enforce the usage of the return value, although it was discarded #4509