Commit ab674b68 authored by Mike Rapoport (Microsoft)'s avatar Mike Rapoport (Microsoft) Committed by Andrew Morton
Browse files

execmem: drop writable parameter from execmem_fill_trapping_insns() 

After update of execmem_cache_free() that made memory writable before
updating it, there is no need to update read only memory, so the writable
parameter to execmem_fill_trapping_insns() is not needed.  Drop it.

Link: https://lkml.kernel.org/r/20250713071730.4117334-7-rppt@kernel.org


Signed-off-by: default avatarMike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Daniel Gomez <da.gomez@samsung.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 3bd4e0ac

arch/x86/mm/init.c

+2 −6
Original line number Diff line number Diff line
@@ -1063,13 +1063,9 @@ unsigned long arch_max_swapfile_size(void) 
static struct execmem_info execmem_info __ro_after_init;



#ifdef CONFIG_ARCH_HAS_EXECMEM_ROX

void execmem_fill_trapping_insns(void *ptr, size_t size, bool writeable)

void execmem_fill_trapping_insns(void *ptr, size_t size)

{

	/* fill memory with INT3 instructions */

	if (writeable)

	memset(ptr, INT3_INSN_OPCODE, size);

	else

		text_poke_set(ptr, INT3_INSN_OPCODE, size);

}

#endif

include/linux/execmem.h

+1 −2
Original line number Diff line number Diff line
@@ -60,12 +60,11 @@ enum execmem_range_flags { 
 *				 will trap

 * @ptr:	pointer to memory to fill

 * @size:	size of the range to fill

 * @writable:	is the memory poited by @ptr is writable or ROX

 *

 * A hook for architecures to fill execmem ranges with invalid instructions.

 * Architectures that use EXECMEM_ROX_CACHE must implement this.

 */

void execmem_fill_trapping_insns(void *ptr, size_t size, bool writable);

void execmem_fill_trapping_insns(void *ptr, size_t size);



/**

 * execmem_restore_rox - restore read-only-execute permissions

mm/execmem.c

+2 −2
Original line number Diff line number Diff line
@@ -304,7 +304,7 @@ static int execmem_cache_populate(struct execmem_range *range, size_t size) 
		goto err_free_mem;



	/* fill memory with instructions that will trap */

	execmem_fill_trapping_insns(p, alloc_size, /* writable = */ true);

	execmem_fill_trapping_insns(p, alloc_size);



	err = set_memory_rox((unsigned long)p, vm->nr_pages);

	if (err)
@@ -363,7 +363,7 @@ static int __execmem_cache_free(struct ma_state *mas, void *ptr, gfp_t gfp_mask) 
	if (err)

		return err;



	execmem_fill_trapping_insns(ptr, size, /* writable = */ true);

	execmem_fill_trapping_insns(ptr, size);

	execmem_restore_rox(ptr, size);



	err = execmem_cache_add_locked(ptr, size, gfp_mask);