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authorKees Cook <kees+treewide@kernel.org>2026-09-02 15:31:14 -0700
committerKees Cook <kees@kernel.org>2026-09-04 21:37:00 -0700
commit3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch)
treec65086f9bdcd48c6360fb7cb4598bca084da1f32 /arch/arm/mm/proc-v7-bugs.c
downloadlinux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz
linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook <kees+treewide@kernel.org>
Diffstat (limited to 'arch/arm/mm/proc-v7-bugs.c')
-rw-r--r--arch/arm/mm/proc-v7-bugs.c297
1 files changed, 297 insertions, 0 deletions
diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
new file mode 100644
index 000000000..8bc7a2d6d
--- /dev/null
+++ b/arch/arm/mm/proc-v7-bugs.c
@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/arm-smccc.h>
+#include <linux/kernel.h>
+#include <linux/smp.h>
+
+#include <asm/cp15.h>
+#include <asm/cputype.h>
+#include <asm/proc-fns.h>
+#include <asm/spectre.h>
+#include <asm/system_misc.h>
+
+#ifdef CONFIG_ARM_PSCI
+static int __maybe_unused spectre_v2_get_cpu_fw_mitigation_state(void)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+ ARM_SMCCC_ARCH_WORKAROUND_1, &res);
+
+ switch ((int)res.a0) {
+ case SMCCC_RET_SUCCESS:
+ return SPECTRE_MITIGATED;
+
+ case SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED:
+ return SPECTRE_UNAFFECTED;
+
+ default:
+ return SPECTRE_VULNERABLE;
+ }
+}
+#else
+static int __maybe_unused spectre_v2_get_cpu_fw_mitigation_state(void)
+{
+ return SPECTRE_VULNERABLE;
+}
+#endif
+
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+DEFINE_PER_CPU(harden_branch_predictor_fn_t, harden_branch_predictor_fn);
+
+extern void cpu_v7_iciallu_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
+extern void cpu_v7_bpiall_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
+extern void cpu_v7_smc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
+extern void cpu_v7_hvc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm);
+
+static void harden_branch_predictor_bpiall(void)
+{
+ write_sysreg(0, BPIALL);
+}
+
+static void harden_branch_predictor_iciallu(void)
+{
+ write_sysreg(0, ICIALLU);
+}
+
+static void __maybe_unused call_smc_arch_workaround_1(void)
+{
+ arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL);
+}
+
+static void __maybe_unused call_hvc_arch_workaround_1(void)
+{
+ arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL);
+}
+
+static unsigned int spectre_v2_install_workaround(unsigned int method)
+{
+ const char *spectre_v2_method = NULL;
+ int cpu = smp_processor_id();
+
+ if (per_cpu(harden_branch_predictor_fn, cpu))
+ return SPECTRE_MITIGATED;
+
+ switch (method) {
+ case SPECTRE_V2_METHOD_BPIALL:
+ per_cpu(harden_branch_predictor_fn, cpu) =
+ harden_branch_predictor_bpiall;
+ spectre_v2_method = "BPIALL";
+ break;
+
+ case SPECTRE_V2_METHOD_ICIALLU:
+ per_cpu(harden_branch_predictor_fn, cpu) =
+ harden_branch_predictor_iciallu;
+ spectre_v2_method = "ICIALLU";
+ break;
+
+ case SPECTRE_V2_METHOD_HVC:
+ per_cpu(harden_branch_predictor_fn, cpu) =
+ call_hvc_arch_workaround_1;
+ cpu_do_switch_mm = cpu_v7_hvc_switch_mm;
+ spectre_v2_method = "hypervisor";
+ break;
+
+ case SPECTRE_V2_METHOD_SMC:
+ per_cpu(harden_branch_predictor_fn, cpu) =
+ call_smc_arch_workaround_1;
+ cpu_do_switch_mm = cpu_v7_smc_switch_mm;
+ spectre_v2_method = "firmware";
+ break;
+ }
+
+ if (spectre_v2_method)
+ pr_info("CPU%u: Spectre v2: using %s workaround\n",
+ smp_processor_id(), spectre_v2_method);
+
+ return SPECTRE_MITIGATED;
+}
+#else
+static unsigned int spectre_v2_install_workaround(unsigned int method)
+{
+ pr_info_once("Spectre V2: workarounds disabled by configuration\n");
+
+ return SPECTRE_VULNERABLE;
+}
+#endif
+
+static void cpu_v7_spectre_v2_init(void)
+{
+ unsigned int state, method = 0;
+
+ switch (read_cpuid_part()) {
+ case ARM_CPU_PART_CORTEX_A8:
+ case ARM_CPU_PART_CORTEX_A9:
+ case ARM_CPU_PART_CORTEX_A12:
+ case ARM_CPU_PART_CORTEX_A17:
+ case ARM_CPU_PART_CORTEX_A73:
+ case ARM_CPU_PART_CORTEX_A75:
+ state = SPECTRE_MITIGATED;
+ method = SPECTRE_V2_METHOD_BPIALL;
+ break;
+
+ case ARM_CPU_PART_CORTEX_A15:
+ case ARM_CPU_PART_BRAHMA_B15:
+ state = SPECTRE_MITIGATED;
+ method = SPECTRE_V2_METHOD_ICIALLU;
+ break;
+
+ case ARM_CPU_PART_BRAHMA_B53:
+ /* Requires no workaround */
+ state = SPECTRE_UNAFFECTED;
+ break;
+
+ default:
+ /* Other ARM CPUs require no workaround */
+ if (read_cpuid_implementor() == ARM_CPU_IMP_ARM) {
+ state = SPECTRE_UNAFFECTED;
+ break;
+ }
+
+ fallthrough;
+
+ /* Cortex A57/A72 require firmware workaround */
+ case ARM_CPU_PART_CORTEX_A57:
+ case ARM_CPU_PART_CORTEX_A72:
+ state = spectre_v2_get_cpu_fw_mitigation_state();
+ if (state != SPECTRE_MITIGATED)
+ break;
+
+ switch (arm_smccc_1_1_get_conduit()) {
+ case SMCCC_CONDUIT_HVC:
+ method = SPECTRE_V2_METHOD_HVC;
+ break;
+
+ case SMCCC_CONDUIT_SMC:
+ method = SPECTRE_V2_METHOD_SMC;
+ break;
+
+ default:
+ state = SPECTRE_VULNERABLE;
+ break;
+ }
+ }
+
+ if (state == SPECTRE_MITIGATED)
+ state = spectre_v2_install_workaround(method);
+
+ spectre_v2_update_state(state, method);
+}
+
+#ifdef CONFIG_HARDEN_BRANCH_HISTORY
+static int spectre_bhb_method;
+
+static const char *spectre_bhb_method_name(int method)
+{
+ switch (method) {
+ case SPECTRE_V2_METHOD_LOOP8:
+ return "loop";
+
+ case SPECTRE_V2_METHOD_BPIALL:
+ return "BPIALL";
+
+ default:
+ return "unknown";
+ }
+}
+
+static int spectre_bhb_install_workaround(int method)
+{
+ if (spectre_bhb_method != method) {
+ if (spectre_bhb_method) {
+ pr_err("CPU%u: Spectre BHB: method disagreement, system vulnerable\n",
+ smp_processor_id());
+
+ return SPECTRE_VULNERABLE;
+ }
+
+ if (spectre_bhb_update_vectors(method) == SPECTRE_VULNERABLE)
+ return SPECTRE_VULNERABLE;
+
+ spectre_bhb_method = method;
+
+ pr_info("CPU%u: Spectre BHB: enabling %s workaround for all CPUs\n",
+ smp_processor_id(), spectre_bhb_method_name(method));
+ }
+
+ return SPECTRE_MITIGATED;
+}
+#else
+static int spectre_bhb_install_workaround(int method)
+{
+ return SPECTRE_VULNERABLE;
+}
+#endif
+
+static void cpu_v7_spectre_bhb_init(void)
+{
+ unsigned int state, method = 0;
+
+ switch (read_cpuid_part()) {
+ case ARM_CPU_PART_CORTEX_A15:
+ case ARM_CPU_PART_BRAHMA_B15:
+ case ARM_CPU_PART_CORTEX_A57:
+ case ARM_CPU_PART_CORTEX_A72:
+ state = SPECTRE_MITIGATED;
+ method = SPECTRE_V2_METHOD_LOOP8;
+ break;
+
+ case ARM_CPU_PART_CORTEX_A73:
+ case ARM_CPU_PART_CORTEX_A75:
+ state = SPECTRE_MITIGATED;
+ method = SPECTRE_V2_METHOD_BPIALL;
+ break;
+
+ default:
+ state = SPECTRE_UNAFFECTED;
+ break;
+ }
+
+ if (state == SPECTRE_MITIGATED)
+ state = spectre_bhb_install_workaround(method);
+
+ spectre_v2_update_state(state, method);
+}
+
+static __maybe_unused bool cpu_v7_check_auxcr_set(bool *warned,
+ u32 mask, const char *msg)
+{
+ u32 aux_cr;
+
+ asm("mrc p15, 0, %0, c1, c0, 1" : "=r" (aux_cr));
+
+ if ((aux_cr & mask) != mask) {
+ if (!*warned)
+ pr_err("CPU%u: %s", smp_processor_id(), msg);
+ *warned = true;
+ return false;
+ }
+ return true;
+}
+
+static DEFINE_PER_CPU(bool, spectre_warned);
+
+static bool check_spectre_auxcr(bool *warned, u32 bit)
+{
+ return IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR) &&
+ cpu_v7_check_auxcr_set(warned, bit,
+ "Spectre v2: firmware did not set auxiliary control register IBE bit, system vulnerable\n");
+}
+
+void cpu_v7_ca8_ibe(void)
+{
+ if (check_spectre_auxcr(this_cpu_ptr(&spectre_warned), BIT(6)))
+ cpu_v7_spectre_v2_init();
+}
+
+void cpu_v7_ca15_ibe(void)
+{
+ if (check_spectre_auxcr(this_cpu_ptr(&spectre_warned), BIT(0)))
+ cpu_v7_spectre_v2_init();
+ cpu_v7_spectre_bhb_init();
+}
+
+void cpu_v7_bugs_init(void)
+{
+ cpu_v7_spectre_v2_init();
+ cpu_v7_spectre_bhb_init();
+}