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Diffstat (limited to 'arch/arm64/kernel/process.c')
-rw-r--r--arch/arm64/kernel/process.c71
1 files changed, 47 insertions, 24 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index f1804496b935..4784011cecac 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -21,6 +21,7 @@
#include <linux/lockdep.h>
#include <linux/mman.h>
#include <linux/mm.h>
+#include <linux/nospec.h>
#include <linux/stddef.h>
#include <linux/sysctl.h>
#include <linux/unistd.h>
@@ -52,6 +53,7 @@
#include <asm/exec.h>
#include <asm/fpsimd.h>
#include <asm/mmu_context.h>
+#include <asm/mte.h>
#include <asm/processor.h>
#include <asm/pointer_auth.h>
#include <asm/stacktrace.h>
@@ -239,7 +241,7 @@ static void print_pstate(struct pt_regs *regs)
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 BTYPE=%s)\n",
+ printk("pstate: %08llx (%c%c%c%c %c%c%c%c %cPAN %cUAO %cTCO BTYPE=%s)\n",
pstate,
pstate & PSR_N_BIT ? 'N' : 'n',
pstate & PSR_Z_BIT ? 'Z' : 'z',
@@ -251,6 +253,7 @@ static void print_pstate(struct pt_regs *regs)
pstate & PSR_F_BIT ? 'F' : 'f',
pstate & PSR_PAN_BIT ? '+' : '-',
pstate & PSR_UAO_BIT ? '+' : '-',
+ pstate & PSR_TCO_BIT ? '+' : '-',
btype_str);
}
}
@@ -336,6 +339,7 @@ void flush_thread(void)
tls_thread_flush();
flush_ptrace_hw_breakpoint(current);
flush_tagged_addr_state();
+ flush_mte_state();
}
void release_thread(struct task_struct *dead_task)
@@ -368,6 +372,9 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
dst->thread.sve_state = NULL;
clear_tsk_thread_flag(dst, TIF_SVE);
+ /* clear any pending asynchronous tag fault raised by the parent */
+ clear_tsk_thread_flag(dst, TIF_MTE_ASYNC_FAULT);
+
return 0;
}
@@ -421,8 +428,7 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start,
cpus_have_const_cap(ARM64_HAS_UAO))
childregs->pstate |= PSR_UAO_BIT;
- if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE)
- set_ssbs_bit(childregs);
+ spectre_v4_enable_task_mitigation(p);
if (system_uses_irq_prio_masking())
childregs->pmr_save = GIC_PRIO_IRQON;
@@ -472,8 +478,6 @@ void uao_thread_switch(struct task_struct *next)
*/
static void ssbs_thread_switch(struct task_struct *next)
{
- struct pt_regs *regs = task_pt_regs(next);
-
/*
* Nothing to do for kernel threads, but 'regs' may be junk
* (e.g. idle task) so check the flags and bail early.
@@ -485,18 +489,10 @@ static void ssbs_thread_switch(struct task_struct *next)
* If all CPUs implement the SSBS extension, then we just need to
* context-switch the PSTATE field.
*/
- if (cpu_have_feature(cpu_feature(SSBS)))
+ if (cpus_have_const_cap(ARM64_SSBS))
return;
- /* If the mitigation is enabled, then we leave SSBS clear. */
- if ((arm64_get_ssbd_state() == ARM64_SSBD_FORCE_ENABLE) ||
- test_tsk_thread_flag(next, TIF_SSBD))
- return;
-
- if (compat_user_mode(regs))
- set_compat_ssbs_bit(regs);
- else if (user_mode(regs))
- set_ssbs_bit(regs);
+ spectre_v4_enable_task_mitigation(next);
}
/*
@@ -571,6 +567,13 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev,
*/
dsb(ish);
+ /*
+ * MTE thread switching must happen after the DSB above to ensure that
+ * any asynchronous tag check faults have been logged in the TFSR*_EL1
+ * registers.
+ */
+ mte_thread_switch(next);
+
/* the actual thread switch */
last = cpu_switch_to(prev, next);
@@ -620,6 +623,11 @@ void arch_setup_new_exec(void)
current->mm->context.flags = is_compat_task() ? MMCF_AARCH32 : 0;
ptrauth_thread_init_user(current);
+
+ if (task_spec_ssb_noexec(current)) {
+ arch_prctl_spec_ctrl_set(current, PR_SPEC_STORE_BYPASS,
+ PR_SPEC_ENABLE);
+ }
}
#ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
@@ -628,11 +636,18 @@ void arch_setup_new_exec(void)
*/
static unsigned int tagged_addr_disabled;
-long set_tagged_addr_ctrl(unsigned long arg)
+long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg)
{
- if (is_compat_task())
+ unsigned long valid_mask = PR_TAGGED_ADDR_ENABLE;
+ struct thread_info *ti = task_thread_info(task);
+
+ if (is_compat_thread(ti))
return -EINVAL;
- if (arg & ~PR_TAGGED_ADDR_ENABLE)
+
+ if (system_supports_mte())
+ valid_mask |= PR_MTE_TCF_MASK | PR_MTE_TAG_MASK;
+
+ if (arg & ~valid_mask)
return -EINVAL;
/*
@@ -642,20 +657,28 @@ long set_tagged_addr_ctrl(unsigned long arg)
if (arg & PR_TAGGED_ADDR_ENABLE && tagged_addr_disabled)
return -EINVAL;
- update_thread_flag(TIF_TAGGED_ADDR, arg & PR_TAGGED_ADDR_ENABLE);
+ if (set_mte_ctrl(task, arg) != 0)
+ return -EINVAL;
+
+ update_ti_thread_flag(ti, TIF_TAGGED_ADDR, arg & PR_TAGGED_ADDR_ENABLE);
return 0;
}
-long get_tagged_addr_ctrl(void)
+long get_tagged_addr_ctrl(struct task_struct *task)
{
- if (is_compat_task())
+ long ret = 0;
+ struct thread_info *ti = task_thread_info(task);
+
+ if (is_compat_thread(ti))
return -EINVAL;
- if (test_thread_flag(TIF_TAGGED_ADDR))
- return PR_TAGGED_ADDR_ENABLE;
+ if (test_ti_thread_flag(ti, TIF_TAGGED_ADDR))
+ ret = PR_TAGGED_ADDR_ENABLE;
- return 0;
+ ret |= get_mte_ctrl(task);
+
+ return ret;
}
/*