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-rw-r--r--arch/powerpc/kernel/dt_cpu_ftrs.c1
-rw-r--r--arch/powerpc/kernel/entry_32.S2
-rw-r--r--arch/powerpc/kernel/kprobes.c3
-rw-r--r--arch/powerpc/kernel/paca.c14
-rw-r--r--arch/powerpc/kernel/prom_init.c3
-rw-r--r--arch/powerpc/kernel/setup.h6
-rw-r--r--arch/powerpc/kernel/setup_64.c34
-rw-r--r--arch/powerpc/kernel/signal_64.c4
-rw-r--r--arch/powerpc/kernel/time.c44
9 files changed, 65 insertions, 46 deletions
diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c
index 182b4047c1ef..36bc0d5c4f3a 100644
--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
+++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
@@ -139,7 +139,6 @@ static void __init cpufeatures_setup_cpu(void)
/* Initialize the base environment -- clear FSCR/HFSCR. */
hv_mode = !!(mfmsr() & MSR_HV);
if (hv_mode) {
- /* CPU_FTR_HVMODE is used early in PACA setup */
cur_cpu_spec->cpu_features |= CPU_FTR_HVMODE;
mtspr(SPRN_HFSCR, 0);
}
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 16af0d8d90a8..89e7f891bcd0 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -710,7 +710,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_SPE)
stw r10,_CCR(r1)
stw r1,KSP(r3) /* Set old stack pointer */
- kuap_check r2, r4
+ kuap_check r2, r0
#ifdef CONFIG_SMP
/* We need a sync somewhere here to make sure that if the
* previous task gets rescheduled on another CPU, it sees all
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 2d27ec4feee4..9b340af02c38 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -264,6 +264,9 @@ int kprobe_handler(struct pt_regs *regs)
if (user_mode(regs))
return 0;
+ if (!(regs->msr & MSR_IR) || !(regs->msr & MSR_DR))
+ return 0;
+
/*
* We don't want to be preempted for the entire
* duration of kprobe processing
diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index 949eceb254d8..3f91ccaa9c74 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -176,7 +176,7 @@ static struct slb_shadow * __init new_slb_shadow(int cpu, unsigned long limit)
struct paca_struct **paca_ptrs __read_mostly;
EXPORT_SYMBOL(paca_ptrs);
-void __init initialise_paca(struct paca_struct *new_paca, int cpu)
+void __init __nostackprotector initialise_paca(struct paca_struct *new_paca, int cpu)
{
#ifdef CONFIG_PPC_PSERIES
new_paca->lppaca_ptr = NULL;
@@ -205,7 +205,7 @@ void __init initialise_paca(struct paca_struct *new_paca, int cpu)
}
/* Put the paca pointer into r13 and SPRG_PACA */
-void setup_paca(struct paca_struct *new_paca)
+void __nostackprotector setup_paca(struct paca_struct *new_paca)
{
/* Setup r13 */
local_paca = new_paca;
@@ -214,11 +214,15 @@ void setup_paca(struct paca_struct *new_paca)
/* On Book3E, initialize the TLB miss exception frames */
mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
#else
- /* In HV mode, we setup both HPACA and PACA to avoid problems
+ /*
+ * In HV mode, we setup both HPACA and PACA to avoid problems
* if we do a GET_PACA() before the feature fixups have been
- * applied
+ * applied.
+ *
+ * Normally you should test against CPU_FTR_HVMODE, but CPU features
+ * are not yet set up when we first reach here.
*/
- if (early_cpu_has_feature(CPU_FTR_HVMODE))
+ if (mfmsr() & MSR_HV)
mtspr(SPRN_SPRG_HPACA, local_paca);
#endif
mtspr(SPRN_SPRG_PACA, local_paca);
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 577345382b23..673f13b87db1 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -1773,6 +1773,9 @@ static void __init prom_rtas_os_term(char *str)
if (token == 0)
prom_panic("Could not get token for ibm,os-term\n");
os_term_args.token = cpu_to_be32(token);
+ os_term_args.nargs = cpu_to_be32(1);
+ os_term_args.nret = cpu_to_be32(1);
+ os_term_args.args[0] = cpu_to_be32(__pa(str));
prom_rtas_hcall((uint64_t)&os_term_args);
}
#endif /* CONFIG_PPC_SVM */
diff --git a/arch/powerpc/kernel/setup.h b/arch/powerpc/kernel/setup.h
index 2dd0d9cb5a20..2ec835574cc9 100644
--- a/arch/powerpc/kernel/setup.h
+++ b/arch/powerpc/kernel/setup.h
@@ -8,6 +8,12 @@
#ifndef __ARCH_POWERPC_KERNEL_SETUP_H
#define __ARCH_POWERPC_KERNEL_SETUP_H
+#ifdef CONFIG_CC_IS_CLANG
+#define __nostackprotector
+#else
+#define __nostackprotector __attribute__((__optimize__("no-stack-protector")))
+#endif
+
void initialize_cache_info(void);
void irqstack_early_init(void);
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index e05e6dd67ae6..8105010b0e76 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -279,24 +279,42 @@ void __init record_spr_defaults(void)
* device-tree is not accessible via normal means at this point.
*/
-void __init early_setup(unsigned long dt_ptr)
+void __init __nostackprotector early_setup(unsigned long dt_ptr)
{
static __initdata struct paca_struct boot_paca;
/* -------- printk is _NOT_ safe to use here ! ------- */
- /* Try new device tree based feature discovery ... */
- if (!dt_cpu_ftrs_init(__va(dt_ptr)))
- /* Otherwise use the old style CPU table */
- identify_cpu(0, mfspr(SPRN_PVR));
-
- /* Assume we're on cpu 0 for now. Don't write to the paca yet! */
+ /*
+ * Assume we're on cpu 0 for now.
+ *
+ * We need to load a PACA very early for a few reasons.
+ *
+ * The stack protector canary is stored in the paca, so as soon as we
+ * call any stack protected code we need r13 pointing somewhere valid.
+ *
+ * If we are using kcov it will call in_task() in its instrumentation,
+ * which relies on the current task from the PACA.
+ *
+ * dt_cpu_ftrs_init() calls into generic OF/fdt code, as well as
+ * printk(), which can trigger both stack protector and kcov.
+ *
+ * percpu variables and spin locks also use the paca.
+ *
+ * So set up a temporary paca. It will be replaced below once we know
+ * what CPU we are on.
+ */
initialise_paca(&boot_paca, 0);
setup_paca(&boot_paca);
fixup_boot_paca();
/* -------- printk is now safe to use ------- */
+ /* Try new device tree based feature discovery ... */
+ if (!dt_cpu_ftrs_init(__va(dt_ptr)))
+ /* Otherwise use the old style CPU table */
+ identify_cpu(0, mfspr(SPRN_PVR));
+
/* Enable early debugging if any specified (see udbg.h) */
udbg_early_init();
@@ -516,6 +534,8 @@ static bool __init parse_cache_info(struct device_node *np,
lsizep = of_get_property(np, propnames[3], NULL);
if (bsizep == NULL)
bsizep = lsizep;
+ if (lsizep == NULL)
+ lsizep = bsizep;
if (lsizep != NULL)
lsize = be32_to_cpu(*lsizep);
if (bsizep != NULL)
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 84ed2e77ef9c..adfde59cf4ba 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -473,8 +473,10 @@ static long restore_tm_sigcontexts(struct task_struct *tsk,
err |= __get_user(tsk->thread.ckpt_regs.ccr,
&sc->gp_regs[PT_CCR]);
+ /* Don't allow userspace to set the trap value */
+ regs->trap = 0;
+
/* These regs are not checkpointed; they can go in 'regs'. */
- err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]);
err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 1168e8b37e30..716f8d0960a7 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -522,35 +522,6 @@ static inline void clear_irq_work_pending(void)
"i" (offsetof(struct paca_struct, irq_work_pending)));
}
-void arch_irq_work_raise(void)
-{
- preempt_disable();
- set_irq_work_pending_flag();
- /*
- * Non-nmi code running with interrupts disabled will replay
- * irq_happened before it re-enables interrupts, so setthe
- * decrementer there instead of causing a hardware exception
- * which would immediately hit the masked interrupt handler
- * and have the net effect of setting the decrementer in
- * irq_happened.
- *
- * NMI interrupts can not check this when they return, so the
- * decrementer hardware exception is raised, which will fire
- * when interrupts are next enabled.
- *
- * BookE does not support this yet, it must audit all NMI
- * interrupt handlers to ensure they call nmi_enter() so this
- * check would be correct.
- */
- if (IS_ENABLED(CONFIG_BOOKE) || !irqs_disabled() || in_nmi()) {
- set_dec(1);
- } else {
- hard_irq_disable();
- local_paca->irq_happened |= PACA_IRQ_DEC;
- }
- preempt_enable();
-}
-
#else /* 32-bit */
DEFINE_PER_CPU(u8, irq_work_pending);
@@ -559,16 +530,27 @@ DEFINE_PER_CPU(u8, irq_work_pending);
#define test_irq_work_pending() __this_cpu_read(irq_work_pending)
#define clear_irq_work_pending() __this_cpu_write(irq_work_pending, 0)
+#endif /* 32 vs 64 bit */
+
void arch_irq_work_raise(void)
{
+ /*
+ * 64-bit code that uses irq soft-mask can just cause an immediate
+ * interrupt here that gets soft masked, if this is called under
+ * local_irq_disable(). It might be possible to prevent that happening
+ * by noticing interrupts are disabled and setting decrementer pending
+ * to be replayed when irqs are enabled. The problem there is that
+ * tracing can call irq_work_raise, including in code that does low
+ * level manipulations of irq soft-mask state (e.g., trace_hardirqs_on)
+ * which could get tangled up if we're messing with the same state
+ * here.
+ */
preempt_disable();
set_irq_work_pending_flag();
set_dec(1);
preempt_enable();
}
-#endif /* 32 vs 64 bit */
-
#else /* CONFIG_IRQ_WORK */
#define test_irq_work_pending() 0