Mike Rapoport (Microsoft) c7a2a36182 x86/bpf: Make arch_bpf_trampoline_size allocate from EXECMEM_MODULE_DATA ... Jiri Olsa reports slowdown of tracing_multi benchmark that allocates huge number of trampolines [1]. The slowdown caused by extra protection changes in execmem_alloc_rw() and execmem_free(). With ROX caches enabled, all execmem allocations except EXECMEM_MODULE_DATA are ROX after the allocation. execmem_alloc_rw() temporarily sets them to W+NX and execmem_free() resets them back to ROX. The only user of bpf_jit_alloc_exec_rw() is x86::arch_bpf_trampoline_size() that only needs a temporary writable buffer in the modules address space. On x86 executable memory and module data are constrained to the same address range, so x86::arch_bpf_trampoline_size() can directly use execmem_alloc(EXECMEM_MODULE_DATA) Replace the call to bpf_jit_alloc_exec_rw() with a call to execmem_alloc(EXECMEM_MODULE_DATA) in x86::arch_bpf_trampoline_size() and drop bpf_jit_alloc_exec_rw() helper. Fixes: 5bf02dbf39 ("bpf, x86: Make sure allocation in arch_bpf_trampoline_size() is writable") Reported-by: Jiri Olsa <olsajiri@gmail.com> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/all/an8r7EODLIL-bZM3@krava Link: https://lore.kernel.org/bpf/20260818130510.3110054-1-rppt@kernel.org		2026-08-20 17:52:31 +02:00
..
bpf_jit_comp.c	x86/bpf: Make arch_bpf_trampoline_size allocate from EXECMEM_MODULE_DATA	2026-08-20 17:52:31 +02:00
bpf_jit_comp32.c	bpf: Pass bpf_verifier_env to JIT	2026-04-16 07:03:40 -07:00
bpf_timed_may_goto.S	bpf, x86: Fix objtool warning for timed may_goto	2025-03-15 15:55:14 -07:00
Makefile	bpf, x86: Add x86 JIT support for timed may_goto	2025-03-15 11:48:28 -07:00