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: Sami Tolvanen <samitolva...@google.com>
Reviewed-by: Kees Cook <keesc...@chromium.org>
Acked-by: Mark Rutland <mark.rutl...@arm.com>
Tested-by: Nathan Chancellor <nat...@kernel.org>
---
arch/arm64/include/asm/mmu_context.h | 2 +-
arch/arm64/kernel/acpi_parking_protocol.c | 3 ++-
arch/arm64/kernel/cpu-reset.h | 2 +-
arch/arm64/kernel/cpufeature.c | 2 +-
arch/arm64/kernel/psci.c | 3 ++-
arch/arm64/kernel/smp_spin_table.c | 3 ++-
6 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/include/asm/mmu_context.h
b/arch/arm64/include/asm/mmu_context.h
index bd02e99b1a4c..386b96400a57 100644
--- a/arch/arm64/include/asm/mmu_context.h
+++ b/arch/arm64/include/asm/mmu_context.h
@@ -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);
diff --git a/arch/arm64/kernel/acpi_parking_protocol.c
b/arch/arm64/kernel/acpi_parking_protocol.c
index e7c941d8340d..bfeeb5319abf 100644
--- a/arch/arm64/kernel/acpi_parking_protocol.c
+++ b/arch/arm64/kernel/acpi_parking_protocol.c
@@ -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));
diff --git a/arch/arm64/kernel/cpu-reset.h b/arch/arm64/kernel/cpu-reset.h
index ed50e9587ad8..f3adc574f969 100644
--- a/arch/arm64/kernel/cpu-reset.h
+++ b/arch/arm64/kernel/cpu-reset.h
@@ -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);
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index e5281e1c8f1d..0b2e0d7b13ec 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -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));
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index 62d2bda7adb8..ab7f4c476104 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -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);
diff --git a/arch/arm64/kernel/smp_spin_table.c
b/arch/arm64/kernel/smp_spin_table.c
index 056772c26098..c45a83512805 100644
--- a/arch/arm64/kernel/smp_spin_table.c
+++ b/arch/arm64/kernel/smp_spin_table.c
@@ -66,6 +66,7 @@ static int smp_spin_table_cpu_init(unsigned int cpu)
static int smp_spin_table_cpu_prepare(unsigned int cpu)
{
__le64 __iomem *release_addr;
+ phys_addr_t pa_holding_pen =
__pa_symbol(function_nocfi(secondary_holding_pen));
if (!cpu_release_addr[cpu])
return -ENODEV;
@@ -88,7 +89,7 @@ static int smp_spin_table_cpu_prepare(unsigned int cpu)
* boot-loader's endianness before jumping. This is mandated by
* the boot protocol.
*/
- writeq_relaxed(__pa_symbol(secondary_holding_pen), release_addr);
+ writeq_relaxed(pa_holding_pen, release_addr);
__flush_dcache_area((__force void *)release_addr,
sizeof(*release_addr));
--
2.31.1.295.g9ea45b61b8-goog
