Commit 5d79c2be authored by Mike Rapoport (Microsoft)'s avatar Mike Rapoport (Microsoft) Committed by Andrew Morton
Browse files

x86/ftrace: enable EXECMEM_ROX_CACHE for ftrace allocations 

For the most part ftrace uses text poking and can handle ROX memory.  The
only place that requires writable memory is create_trampoline() that
updates the allocated memory and in the end makes it ROX.

Use execmem_alloc_rw() in x86::ftrace::alloc_tramp() and enable ROX cache
for EXECMEM_FTRACE when configuration and CPU features allow that.

Link: https://lkml.kernel.org/r/20250713071730.4117334-9-rppt@kernel.org


Signed-off-by: default avatarMike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Cc: Daniel Gomez <da.gomez@samsung.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 36de1e42

arch/x86/kernel/ftrace.c

+1 −1
Original line number Diff line number Diff line
@@ -263,7 +263,7 @@ void arch_ftrace_update_code(int command) 


static inline void *alloc_tramp(unsigned long size)

{

	return execmem_alloc(EXECMEM_FTRACE, size);

	return execmem_alloc_rw(EXECMEM_FTRACE, size);

}

static inline void tramp_free(void *tramp)

{

arch/x86/mm/init.c

+8 −1
Original line number Diff line number Diff line
@@ -1105,7 +1105,14 @@ struct execmem_info __init *execmem_arch_setup(void) 
				.pgprot	= PAGE_KERNEL_ROX,

				.alignment = MODULE_ALIGN,

			},

			[EXECMEM_FTRACE ... EXECMEM_BPF] = {

			[EXECMEM_FTRACE] = {

				.flags	= flags,

				.start	= start,

				.end	= MODULES_END,

				.pgprot	= pgprot,

				.alignment = MODULE_ALIGN,

			},

			[EXECMEM_BPF] = {

				.flags	= EXECMEM_KASAN_SHADOW,

				.start	= start,

				.end	= MODULES_END,