Commit 1b750c2f authored by Mike Rapoport (IBM)'s avatar Mike Rapoport (IBM) Committed by Luis Chamberlain
Browse files

powerpc: extend execmem_params for kprobes allocations 



powerpc overrides kprobes::alloc_insn_page() to remove writable
permissions when STRICT_MODULE_RWX is on.

Add definition of EXECMEM_KRPOBES to execmem_params to allow using the
generic kprobes::alloc_insn_page() with the desired permissions.

As powerpc uses breakpoint instructions to inject kprobes, it does not
need to constrain kprobe allocations to the modules area and can use the
entire vmalloc address space.

Signed-off-by: default avatarMike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
parent e2effa22

arch/powerpc/kernel/kprobes.c

+0 −20
Original line number Diff line number Diff line
@@ -126,26 +126,6 @@ kprobe_opcode_t *arch_adjust_kprobe_addr(unsigned long addr, unsigned long offse 
	return (kprobe_opcode_t *)(addr + offset);

}



void *alloc_insn_page(void)

{

	void *page;



	page = execmem_alloc(EXECMEM_KPROBES, PAGE_SIZE);

	if (!page)

		return NULL;



	if (strict_module_rwx_enabled()) {

		int err = set_memory_rox((unsigned long)page, 1);



		if (err)

			goto error;

	}

	return page;

error:

	execmem_free(page);

	return NULL;

}



int arch_prepare_kprobe(struct kprobe *p)

{

	int ret = 0;

arch/powerpc/kernel/module.c

+7 −0
Original line number Diff line number Diff line
@@ -94,6 +94,7 @@ static struct execmem_info execmem_info __ro_after_init; 


struct execmem_info __init *execmem_arch_setup(void)

{

	pgprot_t kprobes_prot = strict_module_rwx_enabled() ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC;

	pgprot_t prot = strict_module_rwx_enabled() ? PAGE_KERNEL : PAGE_KERNEL_EXEC;

	unsigned long fallback_start = 0, fallback_end = 0;

	unsigned long start, end;
@@ -132,6 +133,12 @@ struct execmem_info __init *execmem_arch_setup(void) 
				.fallback_start	= fallback_start,

				.fallback_end	= fallback_end,

			},

			[EXECMEM_KPROBES] = {

				.start	= VMALLOC_START,

				.end	= VMALLOC_END,

				.pgprot	= kprobes_prot,

				.alignment = 1,

			},

			[EXECMEM_MODULE_DATA] = {

				.start	= VMALLOC_START,

				.end	= VMALLOC_END,