Commit bde33977 authored by Sami Tolvanen's avatar Sami Tolvanen Committed by Kees Cook
Browse files

arm64: use function_nocfi with __pa_symbol 



With CONFIG_CFI_CLANG, the compiler replaces function address
references with the address of the function's CFI jump table
entry. This means that __pa_symbol(function) returns the physical
address of the jump table entry, which can lead to address space
confusion as the jump table points to the function's virtual
address. Therefore, use the function_nocfi() macro to ensure we are
always taking the address of the actual function instead.

Signed-off-by: default avatarSami Tolvanen <samitolvanen@google.com>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Tested-by: default avatarNathan Chancellor <nathan@kernel.org>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-14-samitolvanen@google.com
parent 4ecfca89

arch/arm64/include/asm/mmu_context.h

+1 −1
Original line number Diff line number Diff line
@@ -140,7 +140,7 @@ static inline void cpu_replace_ttbr1(pgd_t *pgdp) 
		ttbr1 |= TTBR_CNP_BIT;

	}



	replace_phys = (void *)__pa_symbol(idmap_cpu_replace_ttbr1);

	replace_phys = (void *)__pa_symbol(function_nocfi(idmap_cpu_replace_ttbr1));



	cpu_install_idmap();

	replace_phys(ttbr1);

arch/arm64/kernel/acpi_parking_protocol.c

+2 −1
Original line number Diff line number Diff line
@@ -99,7 +99,8 @@ static int acpi_parking_protocol_cpu_boot(unsigned int cpu) 
	 * that read this address need to convert this address to the

	 * Boot-Loader's endianness before jumping.

	 */

	writeq_relaxed(__pa_symbol(secondary_entry), &mailbox->entry_point);

	writeq_relaxed(__pa_symbol(function_nocfi(secondary_entry)),

		       &mailbox->entry_point);

	writel_relaxed(cpu_entry->gic_cpu_id, &mailbox->cpu_id);



	arch_send_wakeup_ipi_mask(cpumask_of(cpu));

arch/arm64/kernel/cpu-reset.h

+1 −1
Original line number Diff line number Diff line
@@ -22,7 +22,7 @@ static inline void __noreturn cpu_soft_restart(unsigned long entry, 


	unsigned long el2_switch = !is_kernel_in_hyp_mode() &&

		is_hyp_mode_available();

	restart = (void *)__pa_symbol(__cpu_soft_restart);

	restart = (void *)__pa_symbol(function_nocfi(__cpu_soft_restart));



	cpu_install_idmap();

	restart(el2_switch, entry, arg0, arg1, arg2);

arch/arm64/kernel/cpufeature.c

+1 −1
Original line number Diff line number Diff line
@@ -1462,7 +1462,7 @@ kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused) 
	if (arm64_use_ng_mappings)

		return;



	remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings);

	remap_fn = (void *)__pa_symbol(function_nocfi(idmap_kpti_install_ng_mappings));



	cpu_install_idmap();

	remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir));

arch/arm64/kernel/psci.c

+2 −1
Original line number Diff line number Diff line
@@ -38,7 +38,8 @@ static int __init cpu_psci_cpu_prepare(unsigned int cpu) 


static int cpu_psci_cpu_boot(unsigned int cpu)

{

	int err = psci_ops.cpu_on(cpu_logical_map(cpu), __pa_symbol(secondary_entry));

	phys_addr_t pa_secondary_entry = __pa_symbol(function_nocfi(secondary_entry));

	int err = psci_ops.cpu_on(cpu_logical_map(cpu), pa_secondary_entry);

	if (err)

		pr_err("failed to boot CPU%d (%d)\n", cpu, err);