Merge tag 'printk-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk

Pull printk updates from Petr Mladek:

 - Allow state reset of printk_once() calls.

 - Prevent crashes when dereferencing invalid pointers in vsprintf().
   Only the first byte is checked for simplicity.

 - Make vsprintf warnings consistent and inlined.

 - Treewide conversion of obsolete %pf, %pF to %ps, %pF printf
   modifiers.

 - Some clean up of vsprintf and test_printf code.

* tag 'printk-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
  lib/vsprintf: Make function pointer_string static
  vsprintf: Limit the length of inlined error messages
  vsprintf: Avoid confusion between invalid address and value
  vsprintf: Prevent crash when dereferencing invalid pointers
  vsprintf: Consolidate handling of unknown pointer specifiers
  vsprintf: Factor out %pO handler as kobject_string()
  vsprintf: Factor out %pV handler as va_format()
  vsprintf: Factor out %p[iI] handler as ip_addr_string()
  vsprintf: Do not check address of well-known strings
  vsprintf: Consistent %pK handling for kptr_restrict == 0
  vsprintf: Shuffle restricted_pointer()
  printk: Tie printk_once / printk_deferred_once into .data.once for reset
  treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively
  lib/test_printf: Switch to bitmap_zalloc()

60 files changed, 410 insertions, 272 deletions

diff --git a/Documentation/clearing-warn-once.txt b/Documentation/clearing-warn-once.txt
index 5b1f5d547be1..c68598b31428 100644
--- a/Documentation/clearing-warn-once.txt
+++ b/Documentation/clearing-warn-once.txt
@@ -1,5 +1,5 @@
 
-WARN_ONCE / WARN_ON_ONCE only print a warning once.
+WARN_ONCE / WARN_ON_ONCE / printk_once only emit a message once.
 
 echo 1 > /sys/kernel/debug/clear_warn_once
 
diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst
index c37ec7cd9c06..75d2bbe9813f 100644
--- a/Documentation/core-api/printk-formats.rst
+++ b/Documentation/core-api/printk-formats.rst
@@ -58,6 +58,14 @@ A raw pointer value may be printed with %p which will hash the address
 before printing. The kernel also supports extended specifiers for printing
 pointers of different types.
 
+Some of the extended specifiers print the data on the given address instead
+of printing the address itself. In this case, the following error messages
+might be printed instead of the unreachable information::
+
+	(null)	 data on plain NULL address
+	(efault) data on invalid address
+	(einval) invalid data on a valid address
+
 Plain Pointers
 --------------
 
diff --git a/arch/alpha/kernel/pci_iommu.c b/arch/alpha/kernel/pci_iommu.c
index 3034d6d936d2..242108439f42 100644
--- a/arch/alpha/kernel/pci_iommu.c
+++ b/arch/alpha/kernel/pci_iommu.c
@@ -249,7 +249,7 @@ static int pci_dac_dma_supported(struct pci_dev *dev, u64 mask)
 		ok = 0;
 
 	/* If both conditions above are met, we are fine. */
-	DBGA("pci_dac_dma_supported %s from %pf\n",
+	DBGA("pci_dac_dma_supported %s from %ps\n",
 	     ok ? "yes" : "no", __builtin_return_address(0));
 
 	return ok;
@@ -281,7 +281,7 @@ pci_map_single_1(struct pci_dev *pdev, void *cpu_addr, size_t size,
 	    && paddr + size <= __direct_map_size) {
 		ret = paddr + __direct_map_base;
 
-		DBGA2("pci_map_single: [%p,%zx] -> direct %llx from %pf\n",
+		DBGA2("pci_map_single: [%p,%zx] -> direct %llx from %ps\n",
 		      cpu_addr, size, ret, __builtin_return_address(0));
 
 		return ret;
@@ -292,7 +292,7 @@ pci_map_single_1(struct pci_dev *pdev, void *cpu_addr, size_t size,
 	if (dac_allowed) {
 		ret = paddr + alpha_mv.pci_dac_offset;
 
-		DBGA2("pci_map_single: [%p,%zx] -> DAC %llx from %pf\n",
+		DBGA2("pci_map_single: [%p,%zx] -> DAC %llx from %ps\n",
 		      cpu_addr, size, ret, __builtin_return_address(0));
 
 		return ret;
@@ -329,7 +329,7 @@ pci_map_single_1(struct pci_dev *pdev, void *cpu_addr, size_t size,
 	ret = arena->dma_base + dma_ofs * PAGE_SIZE;
 	ret += (unsigned long)cpu_addr & ~PAGE_MASK;
 
-	DBGA2("pci_map_single: [%p,%zx] np %ld -> sg %llx from %pf\n",
+	DBGA2("pci_map_single: [%p,%zx] np %ld -> sg %llx from %ps\n",
 	      cpu_addr, size, npages, ret, __builtin_return_address(0));
 
 	return ret;
@@ -396,14 +396,14 @@ static void alpha_pci_unmap_page(struct device *dev, dma_addr_t dma_addr,
 	    && dma_addr < __direct_map_base + __direct_map_size) {
 		/* Nothing to do.  */
 
-		DBGA2("pci_unmap_single: direct [%llx,%zx] from %pf\n",
+		DBGA2("pci_unmap_single: direct [%llx,%zx] from %ps\n",
 		      dma_addr, size, __builtin_return_address(0));
 
 		return;
 	}
 
 	if (dma_addr > 0xffffffff) {
-		DBGA2("pci64_unmap_single: DAC [%llx,%zx] from %pf\n",
+		DBGA2("pci64_unmap_single: DAC [%llx,%zx] from %ps\n",
 		      dma_addr, size, __builtin_return_address(0));
 		return;
 	}
@@ -435,7 +435,7 @@ static void alpha_pci_unmap_page(struct device *dev, dma_addr_t dma_addr,
 
 	spin_unlock_irqrestore(&arena->lock, flags);
 
-	DBGA2("pci_unmap_single: sg [%llx,%zx] np %ld from %pf\n",
+	DBGA2("pci_unmap_single: sg [%llx,%zx] np %ld from %ps\n",
 	      dma_addr, size, npages, __builtin_return_address(0));
 }
 
@@ -458,7 +458,7 @@ try_again:
 	cpu_addr = (void *)__get_free_pages(gfp | __GFP_ZERO, order);
 	if (! cpu_addr) {
 		printk(KERN_INFO "pci_alloc_consistent: "
-		       "get_free_pages failed from %pf\n",
+		       "get_free_pages failed from %ps\n",
 			__builtin_return_address(0));
 		/* ??? Really atomic allocation?  Otherwise we could play
 		   with vmalloc and sg if we can't find contiguous memory.  */
@@ -477,7 +477,7 @@ try_again:
 		goto try_again;
 	}
 
-	DBGA2("pci_alloc_consistent: %zx -> [%p,%llx] from %pf\n",
+	DBGA2("pci_alloc_consistent: %zx -> [%p,%llx] from %ps\n",
 	      size, cpu_addr, *dma_addrp, __builtin_return_address(0));
 
 	return cpu_addr;
@@ -497,7 +497,7 @@ static void alpha_pci_free_coherent(struct device *dev, size_t size,
 	pci_unmap_single(pdev, dma_addr, size, PCI_DMA_BIDIRECTIONAL);
 	free_pages((unsigned long)cpu_addr, get_order(size));
 
-	DBGA2("pci_free_consistent: [%llx,%zx] from %pf\n",
+	DBGA2("pci_free_consistent: [%llx,%zx] from %ps\n",
 	      dma_addr, size, __builtin_return_address(0));
 }
 
diff --git a/arch/arm/mach-imx/pm-imx6.c b/arch/arm/mach-imx/pm-imx6.c
index 87f45b926c78..e67e0b2d4ce0 100644
--- a/arch/arm/mach-imx/pm-imx6.c
+++ b/arch/arm/mach-imx/pm-imx6.c
@@ -631,7 +631,7 @@ static void imx6_pm_stby_poweroff(void)
 static int imx6_pm_stby_poweroff_probe(void)
 {
 	if (pm_power_off) {
-		pr_warn("%s: pm_power_off already claimed  %p %pf!\n",
+		pr_warn("%s: pm_power_off already claimed  %p %ps!\n",
 			__func__, pm_power_off, pm_power_off);
 		return -EBUSY;
 	}
diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c
index b54f8f8def36..e376883ab35b 100644
--- a/arch/arm/mm/alignment.c
+++ b/arch/arm/mm/alignment.c
@@ -133,7 +133,7 @@ static const char *usermode_action[] = {
 static int alignment_proc_show(struct seq_file *m, void *v)
 {
 	seq_printf(m, "User:\t\t%lu\n", ai_user);
-	seq_printf(m, "System:\t\t%lu (%pF)\n", ai_sys, ai_sys_last_pc);
+	seq_printf(m, "System:\t\t%lu (%pS)\n", ai_sys, ai_sys_last_pc);
 	seq_printf(m, "Skipped:\t%lu\n", ai_skipped);
 	seq_printf(m, "Half:\t\t%lu\n", ai_half);
 	seq_printf(m, "Word:\t\t%lu\n", ai_word);
diff --git a/arch/arm/nwfpe/fpmodule.c b/arch/arm/nwfpe/fpmodule.c
index 1365e8650843..ee34c76e6624 100644
--- a/arch/arm/nwfpe/fpmodule.c
+++ b/arch/arm/nwfpe/fpmodule.c
@@ -147,7 +147,7 @@ void float_raise(signed char flags)
 #ifdef CONFIG_DEBUG_USER
 	if (flags & debug)
  		printk(KERN_DEBUG
-		       "NWFPE: %s[%d] takes exception %08x at %pf from %08lx\n",
+		       "NWFPE: %s[%d] takes exception %08x at %ps from %08lx\n",
 		       current->comm, current->pid, flags,
 		       __builtin_return_address(0), GET_USERREG()->ARM_pc);
 #endif
diff --git a/arch/microblaze/mm/pgtable.c b/arch/microblaze/mm/pgtable.c
index c2ce1e42b888..8fe54fda31dc 100644
--- a/arch/microblaze/mm/pgtable.c
+++ b/arch/microblaze/mm/pgtable.c
@@ -75,7 +75,7 @@ static void __iomem *__ioremap(phys_addr_t addr, unsigned long size,
 		p >= memory_start && p < virt_to_phys(high_memory) &&
 		!(p >= __virt_to_phys((phys_addr_t)__bss_stop) &&
 		p < __virt_to_phys((phys_addr_t)__bss_stop))) {
-		pr_warn("__ioremap(): phys addr "PTE_FMT" is RAM lr %pf\n",
+		pr_warn("__ioremap(): phys addr "PTE_FMT" is RAM lr %ps\n",
 			(unsigned long)p, __builtin_return_address(0));
 		return NULL;
 	}
diff --git a/arch/sparc/kernel/ds.c b/arch/sparc/kernel/ds.c
index f87265afb175..cad08ccce625 100644
--- a/arch/sparc/kernel/ds.c
+++ b/arch/sparc/kernel/ds.c
@@ -876,7 +876,7 @@ void ldom_power_off(void)
 
 static void ds_conn_reset(struct ds_info *dp)
 {
-	printk(KERN_ERR "ds-%llu: ds_conn_reset() from %pf\n",
+	printk(KERN_ERR "ds-%llu: ds_conn_reset() from %ps\n",
 	       dp->id, __builtin_return_address(0));
 }
 
diff --git a/arch/um/kernel/sysrq.c b/arch/um/kernel/sysrq.c
index 6b995e870d55..05585eef11d9 100644
--- a/arch/um/kernel/sysrq.c
+++ b/arch/um/kernel/sysrq.c
@@ -20,7 +20,7 @@
 
 static void _print_addr(void *data, unsigned long address, int reliable)
 {
-	pr_info(" [<%08lx>] %s%pF\n", address, reliable ? "" : "? ",
+	pr_info(" [<%08lx>] %s%pS\n", address, reliable ? "" : "? ",
 		(void *)address);
 }
 
diff --git a/arch/x86/include/asm/trace/exceptions.h b/arch/x86/include/asm/trace/exceptions.h
index e0e6d7f21399..6b1e87194809 100644
--- a/arch/x86/include/asm/trace/exceptions.h
+++ b/arch/x86/include/asm/trace/exceptions.h
@@ -30,7 +30,7 @@ DECLARE_EVENT_CLASS(x86_exceptions,
 		__entry->error_code = error_code;
 	),
 
-	TP_printk("address=%pf ip=%pf error_code=0x%lx",
+	TP_printk("address=%ps ip=%ps error_code=0x%lx",
 		  (void *)__entry->address, (void *)__entry->ip,
 		  __entry->error_code) );
 
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index 3c4568f8fb28..b0a2de8d2f9e 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -145,7 +145,7 @@ __visible bool ex_handler_rdmsr_unsafe(const struct exception_table_entry *fixup
 				       unsigned long error_code,
 				       unsigned long fault_addr)
 {
-	if (pr_warn_once("unchecked MSR access error: RDMSR from 0x%x at rIP: 0x%lx (%pF)\n",
+	if (pr_warn_once("unchecked MSR access error: RDMSR from 0x%x at rIP: 0x%lx (%pS)\n",
 			 (unsigned int)regs->cx, regs->ip, (void *)regs->ip))
 		show_stack_regs(regs);
 
@@ -162,7 +162,7 @@ __visible bool ex_handler_wrmsr_unsafe(const struct exception_table_entry *fixup
 				       unsigned long error_code,
 				       unsigned long fault_addr)
 {
-	if (pr_warn_once("unchecked MSR access error: WRMSR to 0x%x (tried to write 0x%08x%08x) at rIP: 0x%lx (%pF)\n",
+	if (pr_warn_once("unchecked MSR access error: WRMSR to 0x%x (tried to write 0x%08x%08x) at rIP: 0x%lx (%pS)\n",
 			 (unsigned int)regs->cx, (unsigned int)regs->dx,
 			 (unsigned int)regs->ax,  regs->ip, (void *)regs->ip))
 		show_stack_regs(regs);
diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c
index 0766a08bdf45..07054572297f 100644
--- a/arch/x86/xen/multicalls.c
+++ b/arch/x86/xen/multicalls.c
@@ -105,7 +105,7 @@ void xen_mc_flush(void)
 		for (i = 0; i < b->mcidx; i++) {
 			if (b->entries[i].result < 0) {
 #if MC_DEBUG
-				pr_err("  call %2d: op=%lu arg=[%lx] result=%ld\t%pF\n",
+				pr_err("  call %2d: op=%lu arg=[%lx] result=%ld\t%pS\n",
 				       i + 1,
 				       b->debug[i].op,
 				       b->debug[i].args[0],
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index 5b50f884712c..b859d75eaf9f 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -414,7 +414,7 @@ static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
 	if (adev->wakeup.flags.notifier_present) {
 		pm_wakeup_ws_event(adev->wakeup.ws, 0, acpi_s2idle_wakeup());
 		if (adev->wakeup.context.func) {
-			acpi_handle_debug(handle, "Running %pF for %s\n",
+			acpi_handle_debug(handle, "Running %pS for %s\n",
 					  adev->wakeup.context.func,
 					  dev_name(adev->wakeup.context.dev));
 			adev->wakeup.context.func(&adev->wakeup.context);
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 43e863cc0c1b..10528a7747bf 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -207,7 +207,7 @@ static ktime_t initcall_debug_start(struct device *dev, void *cb)
 	if (!pm_print_times_enabled)
 		return 0;
 
-	dev_info(dev, "calling %pF @ %i, parent: %s\n", cb,
+	dev_info(dev, "calling %pS @ %i, parent: %s\n", cb,
 		 task_pid_nr(current),
 		 dev->parent ? dev_name(dev->parent) : "none");
 	return ktime_get();
@@ -225,7 +225,7 @@ static void initcall_debug_report(struct device *dev, ktime_t calltime,
 	rettime = ktime_get();
 	nsecs = (s64) ktime_to_ns(ktime_sub(rettime, calltime));
 
-	dev_info(dev, "%pF returned %d after %Ld usecs\n", cb, error,
+	dev_info(dev, "%pS returned %d after %Ld usecs\n", cb, error,
 		 (unsigned long long)nsecs >> 10);
 }
 
@@ -2051,7 +2051,7 @@ EXPORT_SYMBOL_GPL(dpm_suspend_start);
 void __suspend_report_result(const char *function, void *fn, int ret)
 {
 	if (ret)
-		pr_err("%s(): %pF returns %d\n", function, fn, ret);
+		pr_err("%s(): %pS returns %d\n", function, fn, ret);
 }
 EXPORT_SYMBOL_GPL(__suspend_report_result);
 
diff --git a/drivers/base/syscore.c b/drivers/base/syscore.c
index 6e076f359dcc..0d346a307140 100644
--- a/drivers/base/syscore.c
+++ b/drivers/base/syscore.c
@@ -62,19 +62,19 @@ int syscore_suspend(void)
 	list_for_each_entry_reverse(ops, &syscore_ops_list, node)
 		if (ops->suspend) {
 			if (initcall_debug)
-				pr_info("PM: Calling %pF\n", ops->suspend);
+				pr_info("PM: Calling %pS\n", ops->suspend);
 			ret = ops->suspend();
 			if (ret)
 				goto err_out;
 			WARN_ONCE(!irqs_disabled(),
-				"Interrupts enabled after %pF\n", ops->suspend);
+				"Interrupts enabled after %pS\n", ops->suspend);
 		}
 
 	trace_suspend_resume(TPS("syscore_suspend"), 0, false);
 	return 0;
 
  err_out:
-	pr_err("PM: System core suspend callback %pF failed.\n", ops->suspend);
+	pr_err("PM: System core suspend callback %pS failed.\n", ops->suspend);
 
 	list_for_each_entry_continue(ops, &syscore_ops_list, node)
 		if (ops->resume)
@@ -100,10 +100,10 @@ void syscore_resume(void)
 	list_for_each_entry(ops, &syscore_ops_list, node)
 		if (ops->resume) {
 			if (initcall_debug)
-				pr_info("PM: Calling %pF\n", ops->resume);
+				pr_info("PM: Calling %pS\n", ops->resume);
 			ops->resume();
 			WARN_ONCE(!irqs_disabled(),
-				"Interrupts enabled after %pF\n", ops->resume);
+				"Interrupts enabled after %pS\n", ops->resume);
 		}
 	trace_suspend_resume(TPS("syscore_resume"), 0, false);
 }
@@ -122,7 +122,7 @@ void syscore_shutdown(void)
 	list_for_each_entry_reverse(ops, &syscore_ops_list, node)
 		if (ops->shutdown) {
 			if (initcall_debug)
-				pr_info("PM: Calling %pF\n", ops->shutdown);
+				pr_info("PM: Calling %pS\n", ops->shutdown);
 			ops->shutdown();
 		}
 
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 843a9b9b3d74..c850bdb6c178 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -6115,7 +6115,7 @@ int drbd_ack_receiver(struct drbd_thread *thi)
 
 			err = cmd->fn(connection, &pi);
 			if (err) {
-				drbd_err(connection, "%pf failed\n", cmd->fn);
+				drbd_err(connection, "%ps failed\n", cmd->fn);
 				goto reconnect;
 			}
 
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 95f608d1a098..49f89db0766f 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -1693,7 +1693,7 @@ irqreturn_t floppy_interrupt(int irq, void *dev_id)
 		/* we don't even know which FDC is the culprit */
 		pr_info("DOR0=%x\n", fdc_state[0].dor);
 		pr_info("floppy interrupt on bizarre fdc %d\n", fdc);
-		pr_info("handler=%pf\n", handler);
+		pr_info("handler=%ps\n", handler);
 		is_alive(__func__, "bizarre fdc");
 		return IRQ_NONE;
 	}
@@ -1752,7 +1752,7 @@ static void reset_interrupt(void)
 	debugt(__func__, "");
 	result();		/* get the status ready for set_fdc */
 	if (FDCS->reset) {
-		pr_info("reset set in interrupt, calling %pf\n", cont->error);
+		pr_info("reset set in interrupt, calling %ps\n", cont->error);
 		cont->error();	/* a reset just after a reset. BAD! */
 	}
 	cont->redo();
@@ -1793,7 +1793,7 @@ static void show_floppy(void)
 	pr_info("\n");
 	pr_info("floppy driver state\n");
 	pr_info("-------------------\n");
-	pr_info("now=%lu last interrupt=%lu diff=%lu last called handler=%pf\n",
+	pr_info("now=%lu last interrupt=%lu diff=%lu last called handler=%ps\n",
 		jiffies, interruptjiffies, jiffies - interruptjiffies,
 		lasthandler);
 
@@ -1812,9 +1812,9 @@ static void show_floppy(void)
 	pr_info("status=%x\n", fd_inb(FD_STATUS));
 	pr_info("fdc_busy=%lu\n", fdc_busy);
 	if (do_floppy)
-		pr_info("do_floppy=%pf\n", do_floppy);
+		pr_info("do_floppy=%ps\n", do_floppy);
 	if (work_pending(&floppy_work))
-		pr_info("floppy_work.func=%pf\n", floppy_work.func);
+		pr_info("floppy_work.func=%ps\n", floppy_work.func);
 	if (delayed_work_pending(&fd_timer))
 		pr_info("delayed work.function=%p expires=%ld\n",
 		       fd_timer.work.func,
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 7ea217c88c2e..db779b650fce 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -466,7 +466,7 @@ static void cpufreq_list_transition_notifiers(void)
 	mutex_lock(&cpufreq_transition_notifier_list.mutex);
 
 	for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next)
-		pr_info("%pF\n", nb->notifier_call);
+		pr_info("%pS\n", nb->notifier_call);
 
 	mutex_unlock(&cpufreq_transition_notifier_list.mutex);
 }
diff --git a/drivers/mmc/core/quirks.h b/drivers/mmc/core/quirks.h
index dd2f73af8f2c..2d2d9ea8be4f 100644
--- a/drivers/mmc/core/quirks.h
+++ b/drivers/mmc/core/quirks.h
@@ -159,7 +159,7 @@ static inline void mmc_fixup_device(struct mmc_card *card,
 		    (f->ext_csd_rev == EXT_CSD_REV_ANY ||
 		     f->ext_csd_rev == card->ext_csd.rev) &&
 		    rev >= f->rev_start && rev <= f->rev_end) {
-			dev_dbg(&card->dev, "calling %pf\