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arm64: use function_nocfi with __pa_symbol

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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 <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-14-samitolvanen@google.com
This commit is contained in:
Sami Tolvanen 2021-04-08 11:28:38 -07:00 committed by Kees Cook
parent 4ecfca8989
commit bde33977bf
6 changed files with 9 additions and 6 deletions
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2
arch/arm64/include/asm/mmu_context.h
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@ -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);

3
arch/arm64/kernel/acpi_parking_protocol.c
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@ -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));

2
arch/arm64/kernel/cpu-reset.h
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@ -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);

2
arch/arm64/kernel/cpufeature.c
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@ -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));

3
arch/arm64/kernel/psci.c
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@ -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);

3
arch/arm64/kernel/smp_spin_table.c
View File

@ -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));