Merge tag 'powerpc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - A fix for a bug in our page table fragment allocator, where a page
     table page could be freed and reallocated for something else while
     still in use, leading to memory corruption etc. The fix reuses
     pt_mm in struct page (x86 only) for a powerpc only refcount.

   - Fixes to our pkey support. Several are user-visible changes, but
     bring us in to line with x86 behaviour and/or fix outright bugs.
     Thanks to Florian Weimer for reporting many of these.

   - A series to improve the hvc driver & related OPAL console code,
     which have been seen to cause hardlockups at times. The hvc driver
     changes in particular have been in linux-next for ~month.

   - Increase our MAX_PHYSMEM_BITS to 128TB when SPARSEMEM_VMEMMAP=y.

   - Remove Power8 DD1 and Power9 DD1 support, neither chip should be in
     use anywhere other than as a paper weight.

   - An optimised memcmp implementation using Power7-or-later VMX
     instructions

   - Support for barrier_nospec on some NXP CPUs.

   - Support for flushing the count cache on context switch on some IBM
     CPUs (controlled by firmware), as a Spectre v2 mitigation.

   - A series to enhance the information we print on unhandled signals
     to bring it into line with other arches, including showing the
     offending VMA and dumping the instructions around the fault.

  Thanks to: Aaro Koskinen, Akshay Adiga, Alastair D'Silva, Alexey
  Kardashevskiy, Alexey Spirkov, Alistair Popple, Andrew Donnellan,
  Aneesh Kumar K.V, Anju T Sudhakar, Arnd Bergmann, Bartosz Golaszewski,
  Benjamin Herrenschmidt, Bharat Bhushan, Bjoern Noetel, Boqun Feng,
  Breno Leitao, Bryant G. Ly, Camelia Groza, Christophe Leroy, Christoph
  Hellwig, Cyril Bur, Dan Carpenter, Daniel Klamt, Darren Stevens, Dave
  Young, David Gibson, Diana Craciun, Finn Thain, Florian Weimer,
  Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven, Geoff Levand,
  Guenter Roeck, Gustavo Romero, Haren Myneni, Hari Bathini, Joel
  Stanley, Jonathan Neuschäfer, Kees Cook, Madhavan Srinivasan, Mahesh
  Salgaonkar, Markus Elfring, Mathieu Malaterre, Mauro S. M. Rodrigues,
  Michael Hanselmann, Michael Neuling, Michael Schmitz, Mukesh Ojha,
  Murilo Opsfelder Araujo, Nicholas Piggin, Parth Y Shah, Paul
  Mackerras, Paul Menzel, Ram Pai, Randy Dunlap, Rashmica Gupta, Reza
  Arbab, Rodrigo R. Galvao, Russell Currey, Sam Bobroff, Scott Wood,
  Shilpasri G Bhat, Simon Guo, Souptick Joarder, Stan Johnson, Thiago
  Jung Bauermann, Tyrel Datwyler, Vaibhav Jain, Vasant Hegde, Venkat
  Rao, zhong jiang"

* tag 'powerpc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (234 commits)
  powerpc/mm/book3s/radix: Add mapping statistics
  powerpc/uaccess: Enable get_user(u64, *p) on 32-bit
  powerpc/mm/hash: Remove unnecessary do { } while(0) loop
  powerpc/64s: move machine check SLB flushing to mm/slb.c
  powerpc/powernv/idle: Fix build error
  powerpc/mm/tlbflush: update the mmu_gather page size while iterating address range
  powerpc/mm: remove warning about ‘type’ being set
  powerpc/32: Include setup.h header file to fix warnings
  powerpc: Move `path` variable inside DEBUG_PROM
  powerpc/powermac: Make some functions static
  powerpc/powermac: Remove variable x that's never read
  cxl: remove a dead branch
  powerpc/powermac: Add missing include of header pmac.h
  powerpc/kexec: Use common error handling code in setup_new_fdt()
  powerpc/xmon: Add address lookup for percpu symbols
  powerpc/mm: remove huge_pte_offset_and_shift() prototype
  powerpc/lib: Use patch_site to patch copy_32 functions once cache is enabled
  powerpc/pseries: Fix endianness while restoring of r3 in MCE handler.
  powerpc/fadump: merge adjacent memory ranges to reduce PT_LOAD segements
  powerpc/fadump: handle crash memory ranges array index overflow
  ...

1 files changed, 125 insertions, 16 deletions

diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index a8b277362931..f6f469fc4073 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -8,6 +8,8 @@
 #include <linux/device.h>
 #include <linux/seq_buf.h>
 
+#include <asm/asm-prototypes.h>
+#include <asm/code-patching.h>
 #include <asm/debugfs.h>
 #include <asm/security_features.h>
 #include <asm/setup.h>
@@ -15,7 +17,15 @@
 
 unsigned long powerpc_security_features __read_mostly = SEC_FTR_DEFAULT;
 
+enum count_cache_flush_type {
+	COUNT_CACHE_FLUSH_NONE	= 0x1,
+	COUNT_CACHE_FLUSH_SW	= 0x2,
+	COUNT_CACHE_FLUSH_HW	= 0x4,
+};
+static enum count_cache_flush_type count_cache_flush_type;
+
 bool barrier_nospec_enabled;
+static bool no_nospec;
 
 static void enable_barrier_nospec(bool enable)
 {
@@ -42,8 +52,17 @@ void setup_barrier_nospec(void)
 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
 		 security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR);
 
-	enable_barrier_nospec(enable);
+	if (!no_nospec)
+		enable_barrier_nospec(enable);
+}
+
+static int __init handle_nospectre_v1(char *p)
+{
+	no_nospec = true;
+
+	return 0;
 }
+early_param("nospectre_v1", handle_nospectre_v1);
 
 #ifdef CONFIG_DEBUG_FS
 static int barrier_nospec_set(void *data, u64 val)
@@ -82,6 +101,7 @@ static __init int barrier_nospec_debugfs_init(void)
 device_initcall(barrier_nospec_debugfs_init);
 #endif /* CONFIG_DEBUG_FS */
 
+#ifdef CONFIG_PPC_BOOK3S_64
 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	bool thread_priv;
@@ -114,51 +134,72 @@ ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, cha
 
 	return sprintf(buf, "Vulnerable\n");
 }
+#endif
 
 ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr, char *buf)
 {
-	if (!security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR))
-		return sprintf(buf, "Not affected\n");
+	struct seq_buf s;
 
-	if (barrier_nospec_enabled)
-		return sprintf(buf, "Mitigation: __user pointer sanitization\n");
+	seq_buf_init(&s, buf, PAGE_SIZE - 1);
 
-	return sprintf(buf, "Vulnerable\n");
+	if (security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR)) {
+		if (barrier_nospec_enabled)
+			seq_buf_printf(&s, "Mitigation: __user pointer sanitization");
+		else
+			seq_buf_printf(&s, "Vulnerable");
+
+		if (security_ftr_enabled(SEC_FTR_SPEC_BAR_ORI31))
+			seq_buf_printf(&s, ", ori31 speculation barrier enabled");
+
+		seq_buf_printf(&s, "\n");
+	} else
+		seq_buf_printf(&s, "Not affected\n");
+
+	return s.len;
 }
 
 ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, char *buf)
 {
-	bool bcs, ccd, ori;
 	struct seq_buf s;
+	bool bcs, ccd;
 
 	seq_buf_init(&s, buf, PAGE_SIZE - 1);
 
 	bcs = security_ftr_enabled(SEC_FTR_BCCTRL_SERIALISED);
 	ccd = security_ftr_enabled(SEC_FTR_COUNT_CACHE_DISABLED);
-	ori = security_ftr_enabled(SEC_FTR_SPEC_BAR_ORI31);
 
-	if (bcs || ccd) {
+	if (bcs || ccd || count_cache_flush_type != COUNT_CACHE_FLUSH_NONE) {
+		bool comma = false;
 		seq_buf_printf(&s, "Mitigation: ");
 
-		if (bcs)
+		if (bcs) {
 			seq_buf_printf(&s, "Indirect branch serialisation (kernel only)");
+			comma = true;
+		}
+
+		if (ccd) {
+			if (comma)
+				seq_buf_printf(&s, ", ");
+			seq_buf_printf(&s, "Indirect branch cache disabled");
+			comma = true;
+		}
 
-		if (bcs && ccd)
+		if (comma)
 			seq_buf_printf(&s, ", ");
 
-		if (ccd)
-			seq_buf_printf(&s, "Indirect branch cache disabled");
+		seq_buf_printf(&s, "Software count cache flush");
+
+		if (count_cache_flush_type == COUNT_CACHE_FLUSH_HW)
+			seq_buf_printf(&s, "(hardware accelerated)");
 	} else
 		seq_buf_printf(&s, "Vulnerable");
 
-	if (ori)
-		seq_buf_printf(&s, ", ori31 speculation barrier enabled");
-
 	seq_buf_printf(&s, "\n");
 
 	return s.len;
 }
 
+#ifdef CONFIG_PPC_BOOK3S_64
 /*
  * Store-forwarding barrier support.
  */
@@ -306,3 +347,71 @@ static __init int stf_barrier_debugfs_init(void)
 }
 device_initcall(stf_barrier_debugfs_init);
 #endif /* CONFIG_DEBUG_FS */
+
+static void toggle_count_cache_flush(bool enable)
+{
+	if (!enable || !security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE)) {
+		patch_instruction_site(&patch__call_flush_count_cache, PPC_INST_NOP);
+		count_cache_flush_type = COUNT_CACHE_FLUSH_NONE;
+		pr_info("count-cache-flush: software flush disabled.\n");
+		return;
+	}
+
+	patch_branch_site(&patch__call_flush_count_cache,
+			  (u64)&flush_count_cache, BRANCH_SET_LINK);
+
+	if (!security_ftr_enabled(SEC_FTR_BCCTR_FLUSH_ASSIST)) {
+		count_cache_flush_type = COUNT_CACHE_FLUSH_SW;
+		pr_info("count-cache-flush: full software flush sequence enabled.\n");
+		return;
+	}
+
+	patch_instruction_site(&patch__flush_count_cache_return, PPC_INST_BLR);
+	count_cache_flush_type = COUNT_CACHE_FLUSH_HW;
+	pr_info("count-cache-flush: hardware assisted flush sequence enabled\n");
+}
+
+void setup_count_cache_flush(void)
+{
+	toggle_count_cache_flush(true);
+}
+
+#ifdef CONFIG_DEBUG_FS
+static int count_cache_flush_set(void *data, u64 val)
+{
+	bool enable;
+
+	if (val == 1)
+		enable = true;
+	else if (val == 0)
+		enable = false;
+	else
+		return -EINVAL;
+
+	toggle_count_cache_flush(enable);
+
+	return 0;
+}
+
+static int count_cache_flush_get(void *data, u64 *val)
+{
+	if (count_cache_flush_type == COUNT_CACHE_FLUSH_NONE)
+		*val = 0;
+	else
+		*val = 1;
+
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(fops_count_cache_flush, count_cache_flush_get,
+			count_cache_flush_set, "%llu\n");
+
+static __init int count_cache_flush_debugfs_init(void)
+{
+	debugfs_create_file("count_cache_flush", 0600, powerpc_debugfs_root,
+			    NULL, &fops_count_cache_flush);
+	return 0;
+}
+device_initcall(count_cache_flush_debugfs_init);
+#endif /* CONFIG_DEBUG_FS */
+#endif /* CONFIG_PPC_BOOK3S_64 */