patchable-function-entry
The -Z patchable-function-entry=total_nops,prefix_nops
or -Z patchable-function-entry=total_nops
compiler flag enables nop padding of function entries with 'total_nops' nops, with
an offset for the entry of the function at 'prefix_nops' nops. In the second form,
'prefix_nops' defaults to 0.
As an illustrative example, -Z patchable-function-entry=3,2
would produce:
nop
nop
function_label:
nop
//Actual function code begins here
This flag is used for hotpatching, especially in the Linux kernel. The flag
arguments are modeled after the -fpatchable-function-entry
flag as defined
for both Clang
and gcc
and is intended to provide the same effect.