diff options
Diffstat (limited to 'arch/arm64/kernel/process.c')
| -rw-r--r-- | arch/arm64/kernel/process.c | 81 |
1 files changed, 50 insertions, 31 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index c8989b999250..19100fe8f7e4 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -6,9 +6,6 @@ * Copyright (C) 1996-2000 Russell King - Converted to ARM. * Copyright (C) 2012 ARM Ltd. */ - -#include <stdarg.h> - #include <linux/compat.h> #include <linux/efi.h> #include <linux/elf.h> @@ -21,6 +18,7 @@ #include <linux/mman.h> #include <linux/mm.h> #include <linux/nospec.h> +#include <linux/sched.h> #include <linux/stddef.h> #include <linux/sysctl.h> #include <linux/unistd.h> @@ -163,7 +161,7 @@ static void print_pstate(struct pt_regs *regs) u64 pstate = regs->pstate; if (compat_user_mode(regs)) { - printk("pstate: %08llx (%c%c%c%c %c %s %s %c%c%c)\n", + printk("pstate: %08llx (%c%c%c%c %c %s %s %c%c%c %cDIT %cSSBS)\n", pstate, pstate & PSR_AA32_N_BIT ? 'N' : 'n', pstate & PSR_AA32_Z_BIT ? 'Z' : 'z', @@ -174,12 +172,14 @@ static void print_pstate(struct pt_regs *regs) pstate & PSR_AA32_E_BIT ? "BE" : "LE", pstate & PSR_AA32_A_BIT ? 'A' : 'a', pstate & PSR_AA32_I_BIT ? 'I' : 'i', - pstate & PSR_AA32_F_BIT ? 'F' : 'f'); + pstate & PSR_AA32_F_BIT ? 'F' : 'f', + pstate & PSR_AA32_DIT_BIT ? '+' : '-', + pstate & PSR_AA32_SSBS_BIT ? '+' : '-'); } else { const char *btype_str = btypes[(pstate & PSR_BTYPE_MASK) >> PSR_BTYPE_SHIFT]; - printk("pstate: %08llx (%c%c%c%c %c%c%c%c %cPAN %cUAO %cTCO BTYPE=%s)\n", + printk("pstate: %08llx (%c%c%c%c %c%c%c%c %cPAN %cUAO %cTCO %cDIT %cSSBS BTYPE=%s)\n", pstate, pstate & PSR_N_BIT ? 'N' : 'n', pstate & PSR_Z_BIT ? 'Z' : 'z', @@ -192,6 +192,8 @@ static void print_pstate(struct pt_regs *regs) pstate & PSR_PAN_BIT ? '+' : '-', pstate & PSR_UAO_BIT ? '+' : '-', pstate & PSR_TCO_BIT ? '+' : '-', + pstate & PSR_DIT_BIT ? '+' : '-', + pstate & PSR_SSBS_BIT ? '+' : '-', btype_str); } } @@ -468,16 +470,13 @@ static void erratum_1418040_thread_switch(struct task_struct *prev, write_sysreg(val, cntkctl_el1); } -static void compat_thread_switch(struct task_struct *next) -{ - if (!is_compat_thread(task_thread_info(next))) - return; - - if (static_branch_unlikely(&arm64_mismatched_32bit_el0)) - set_tsk_thread_flag(next, TIF_NOTIFY_RESUME); -} - -static void update_sctlr_el1(u64 sctlr) +/* + * __switch_to() checks current->thread.sctlr_user as an optimisation. Therefore + * this function must be called with preemption disabled and the update to + * sctlr_user must be made in the same preemption disabled block so that + * __switch_to() does not see the variable update before the SCTLR_EL1 one. + */ +void update_sctlr_el1(u64 sctlr) { /* * EnIA must not be cleared while in the kernel as this is necessary for @@ -489,19 +488,6 @@ static void update_sctlr_el1(u64 sctlr) isb(); } -void set_task_sctlr_el1(u64 sctlr) -{ - /* - * __switch_to() checks current->thread.sctlr as an - * optimisation. Disable preemption so that it does not see - * the variable update before the SCTLR_EL1 one. - */ - preempt_disable(); - current->thread.sctlr_user = sctlr; - update_sctlr_el1(sctlr); - preempt_enable(); -} - /* * Thread switching. */ @@ -518,7 +504,6 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, ssbs_thread_switch(next); erratum_1418040_thread_switch(prev, next); ptrauth_thread_switch_user(next); - compat_thread_switch(next); /* * Complete any pending TLB or cache maintenance on this CPU in case @@ -579,6 +564,28 @@ unsigned long arch_align_stack(unsigned long sp) return sp & ~0xf; } +#ifdef CONFIG_COMPAT +int compat_elf_check_arch(const struct elf32_hdr *hdr) +{ + if (!system_supports_32bit_el0()) + return false; + + if ((hdr)->e_machine != EM_ARM) + return false; + + if (!((hdr)->e_flags & EF_ARM_EABI_MASK)) + return false; + + /* + * Prevent execve() of a 32-bit program from a deadline task + * if the restricted affinity mask would be inadmissible on an + * asymmetric system. + */ + return !static_branch_unlikely(&arm64_mismatched_32bit_el0) || + !dl_task_check_affinity(current, system_32bit_el0_cpumask()); +} +#endif + /* * Called from setup_new_exec() after (COMPAT_)SET_PERSONALITY. */ @@ -588,8 +595,20 @@ void arch_setup_new_exec(void) if (is_compat_task()) { mmflags = MMCF_AARCH32; + + /* + * Restrict the CPU affinity mask for a 32-bit task so that + * it contains only 32-bit-capable CPUs. + * + * From the perspective of the task, this looks similar to + * what would happen if the 64-bit-only CPUs were hot-unplugged + * at the point of execve(), although we try a bit harder to + * honour the cpuset hierarchy. + */ if (static_branch_unlikely(&arm64_mismatched_32bit_el0)) - set_tsk_thread_flag(current, TIF_NOTIFY_RESUME); + force_compatible_cpus_allowed_ptr(current); + } else if (static_branch_unlikely(&arm64_mismatched_32bit_el0)) { + relax_compatible_cpus_allowed_ptr(current); } current->mm->context.flags = mmflags; |