Bug report

Bug description:

In Python/perf_jit_trampoline.c, the perf_map_jit_init function checks for NULL to detect mmap failures, but mmap() returns MAP_FAILED (which is (void*)-1) on error, not NULL.

This means mmap failures are never detected, and jitdump initialization proceeds with an invalid pointer.

CPython versions tested on:

CPython main branch, 3.15, 3.14, 3.13

Operating systems tested on:

Linux

Linked PRs

• gh-144194: Fix mmap failure check in perf_jit_trampoline.c #143713
• [3.14] gh-144194: Fix mmap failure check in perf_jit_trampoline.c (GH-143713) #144301
• [3.13] gh-144194: Fix mmap failure check in perf_jit_trampoline.c (#143713) #144304