Merge tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Vasily Gorbik:

 - Add support for ftrace with direct call and ftrace direct call
   samples.

 - Add support for kernel command lines longer than current 896 bytes
   and make its length configurable.

 - Add support for BEAR enhancement facility to improve last breaking
   event instruction tracking.

 - Add kprobes sanity checks and testcases to prevent kprobe in the mid
   of an instruction.

 - Allow concurrent access to /dev/hwc for the CPUMF users.

 - Various ftrace / jump label improvements.

 - Convert unwinder tests to KUnit.

 - Add s390_iommu_aperture kernel parameter to tweak the limits on
   concurrently usable DMA mappings.

 - Add ap.useirq AP module option which can be used to disable interrupt
   use.

 - Add add_disk() error handling support to block device drivers.

 - Drop arch specific and use generic implementation of strlcpy and
   strrchr.

 - Several __pa/__va usages fixes.

 - Various cio, crypto, pci, kernel doc and other small fixes and
   improvements all over the code.

[ Merge fixup as per https://lore.kernel.org/all/YXAqZ%2FEszRisunQw@osiris/ ]

* tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (63 commits)
  s390: make command line configurable
  s390: support command lines longer than 896 bytes
  s390/kexec_file: move kernel image size check
  s390/pci: add s390_iommu_aperture kernel parameter
  s390/spinlock: remove incorrect kernel doc indicator
  s390/string: use generic strlcpy
  s390/string: use generic strrchr
  s390/ap: function rework based on compiler warning
  s390/cio: make ccw_device_dma_* more robust
  s390/vfio-ap: s390/crypto: fix all kernel-doc warnings
  s390/hmcdrv: fix kernel doc comments
  s390/ap: new module option ap.useirq
  s390/cpumf: Allow multiple processes to access /dev/hwc
  s390/bitops: return true/false (not 1/0) from bool functions
  s390: add support for BEAR enhancement facility
  s390: introduce nospec_uses_trampoline()
  s390: rename last_break to pgm_last_break
  s390/ptrace: add last_break member to pt_regs
  s390/sclp: sort out physical vs virtual pointers usage
  s390/setup: convert start and end initrd pointers to virtual
  ...

4 files changed, 25 insertions, 14 deletions

diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c
index 1141c8d5c0d0..2203164b39da 100644
--- a/arch/s390/mm/cmm.c
+++ b/arch/s390/mm/cmm.c
@@ -14,8 +14,8 @@
 #include <linux/moduleparam.h>
 #include <linux/gfp.h>
 #include <linux/sched.h>
+#include <linux/string_helpers.h>
 #include <linux/sysctl.h>
-#include <linux/ctype.h>
 #include <linux/swap.h>
 #include <linux/kthread.h>
 #include <linux/oom.h>
@@ -394,13 +394,10 @@ static int __init cmm_init(void)
 		goto out_sysctl;
 #ifdef CONFIG_CMM_IUCV
 	/* convert sender to uppercase characters */
-	if (sender) {
-		int len = strlen(sender);
-		while (len--)
-			sender[len] = toupper(sender[len]);
-	} else {
+	if (sender)
+		string_upper(sender, sender);
+	else
 		sender = cmm_default_sender;
-	}
 
 	rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
 	if (rc < 0)
diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c
index 0b0c8c284953..9f9af5298dd6 100644
--- a/arch/s390/mm/dump_pagetables.c
+++ b/arch/s390/mm/dump_pagetables.c
@@ -8,6 +8,7 @@
 #include <linux/kasan.h>
 #include <asm/ptdump.h>
 #include <asm/kasan.h>
+#include <asm/nospec-branch.h>
 #include <asm/sections.h>
 
 static unsigned long max_addr;
@@ -116,8 +117,13 @@ static void note_prot_wx(struct pg_state *st, unsigned long addr)
 		return;
 	if (st->current_prot & _PAGE_NOEXEC)
 		return;
-	/* The first lowcore page is currently still W+X. */
-	if (addr == PAGE_SIZE)
+	/*
+	 * The first lowcore page is W+X if spectre mitigations are using
+	 * trampolines or the BEAR enhancements facility is not installed,
+	 * in which case we have two lpswe instructions in lowcore that need
+	 * to be executable.
+	 */
+	if (addr == PAGE_SIZE && (nospec_uses_trampoline() || !static_key_enabled(&cpu_has_bear)))
 		return;
 	WARN_ONCE(1, "s390/mm: Found insecure W+X mapping at address %pS\n",
 		  (void *)st->start_address);
@@ -203,7 +209,9 @@ void ptdump_check_wx(void)
 	if (st.wx_pages)
 		pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found\n", st.wx_pages);
 	else
-		pr_info("Checked W+X mappings: passed, no unexpected W+X pages found\n");
+		pr_info("Checked W+X mappings: passed, no %sW+X pages found\n",
+			(nospec_uses_trampoline() || !static_key_enabled(&cpu_has_bear)) ?
+			"unexpected " : "");
 }
 #endif /* CONFIG_DEBUG_WX */
 
diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
index fdc86c0e4e6c..654019181a37 100644
--- a/arch/s390/mm/pageattr.c
+++ b/arch/s390/mm/pageattr.c
@@ -57,7 +57,7 @@ void arch_report_meminfo(struct seq_file *m)
 static void pgt_set(unsigned long *old, unsigned long new, unsigned long addr,
 		    unsigned long dtt)
 {
-	unsigned long table, mask;
+	unsigned long *table, mask;
 
 	mask = 0;
 	if (MACHINE_HAS_EDAT2) {
@@ -72,7 +72,7 @@ static void pgt_set(unsigned long *old, unsigned long new, unsigned long addr,
 			mask = ~(PTRS_PER_PTE * sizeof(pte_t) - 1);
 			break;
 		}
-		table = (unsigned long)old & mask;
+		table = (unsigned long *)((unsigned long)old & mask);
 		crdte(*old, new, table, dtt, addr, S390_lowcore.kernel_asce);
 	} else if (MACHINE_HAS_IDTE) {
 		cspg(old, *old, new);
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 2b1c6d916cf9..7d9705eeb02f 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -13,6 +13,7 @@
 #include <linux/hugetlb.h>
 #include <linux/slab.h>
 #include <asm/cacheflush.h>
+#include <asm/nospec-branch.h>
 #include <asm/pgalloc.h>
 #include <asm/setup.h>
 #include <asm/tlbflush.h>
@@ -584,8 +585,13 @@ void __init vmem_map_init(void)
 	__set_memory(__stext_amode31, (__etext_amode31 - __stext_amode31) >> PAGE_SHIFT,
 		     SET_MEMORY_RO | SET_MEMORY_X);
 
-	/* we need lowcore executable for our LPSWE instructions */
-	set_memory_x(0, 1);
+	if (nospec_uses_trampoline() || !static_key_enabled(&cpu_has_bear)) {
+		/*
+		 * Lowcore must be executable for LPSWE
+		 * and expoline trampoline branch instructions.
+		 */
+		set_memory_x(0, 1);
+	}
 
 	pr_info("Write protected kernel read-only data: %luk\n",
 		(unsigned long)(__end_rodata - _stext) >> 10);