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
  ...

1 files changed, 12 insertions, 84 deletions

diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index 5165bf344f95..5510c7d10ddc 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -17,6 +17,7 @@
 #include <linux/kprobes.h>
 #include <trace/syscall.h>
 #include <asm/asm-offsets.h>
+#include <asm/text-patching.h>
 #include <asm/cacheflush.h>
 #include <asm/ftrace.lds.h>
 #include <asm/nospec-branch.h>
@@ -80,17 +81,6 @@ asm(
 
 #ifdef CONFIG_MODULES
 static char *ftrace_plt;
-
-asm(
-	"	.data\n"
-	"ftrace_plt_template:\n"
-	"	basr	%r1,%r0\n"
-	"	lg	%r1,0f-.(%r1)\n"
-	"	br	%r1\n"
-	"0:	.quad	ftrace_caller\n"
-	"ftrace_plt_template_end:\n"
-	"	.previous\n"
-);
 #endif /* CONFIG_MODULES */
 
 static const char *ftrace_shared_hotpatch_trampoline(const char **end)
@@ -116,7 +106,7 @@ static const char *ftrace_shared_hotpatch_trampoline(const char **end)
 
 bool ftrace_need_init_nop(void)
 {
-	return ftrace_shared_hotpatch_trampoline(NULL);
+	return true;
 }
 
 int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
@@ -175,28 +165,6 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 	return 0;
 }
 
-static void ftrace_generate_nop_insn(struct ftrace_insn *insn)
-{
-	/* brcl 0,0 */
-	insn->opc = 0xc004;
-	insn->disp = 0;
-}
-
-static void ftrace_generate_call_insn(struct ftrace_insn *insn,
-				      unsigned long ip)
-{
-	unsigned long target;
-
-	/* brasl r0,ftrace_caller */
-	target = FTRACE_ADDR;
-#ifdef CONFIG_MODULES
-	if (is_module_addr((void *)ip))
-		target = (unsigned long)ftrace_plt;
-#endif /* CONFIG_MODULES */
-	insn->opc = 0xc005;
-	insn->disp = (target - ip) / 2;
-}
-
 static void brcl_disable(void *brcl)
 {
 	u8 op = 0x04; /* set mask field to zero */
@@ -207,23 +175,7 @@ static void brcl_disable(void *brcl)
 int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
 		    unsigned long addr)
 {
-	struct ftrace_insn orig, new, old;
-
-	if (ftrace_shared_hotpatch_trampoline(NULL)) {
-		brcl_disable((void *)rec->ip);
-		return 0;
-	}
-
-	if (copy_from_kernel_nofault(&old, (void *) rec->ip, sizeof(old)))
-		return -EFAULT;
-	/* Replace ftrace call with a nop. */
-	ftrace_generate_call_insn(&orig, rec->ip);
-	ftrace_generate_nop_insn(&new);
-
-	/* Verify that the to be replaced code matches what we expect. */
-	if (memcmp(&orig, &old, sizeof(old)))
-		return -EINVAL;
-	s390_kernel_write((void *) rec->ip, &new, sizeof(new));
+	brcl_disable((void *)rec->ip);
 	return 0;
 }
 
@@ -236,23 +188,7 @@ static void brcl_enable(void *brcl)
 
 int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 {
-	struct ftrace_insn orig, new, old;
-
-	if (ftrace_shared_hotpatch_trampoline(NULL)) {
-		brcl_enable((void *)rec->ip);
-		return 0;
-	}
-
-	if (copy_from_kernel_nofault(&old, (void *) rec->ip, sizeof(old)))
-		return -EFAULT;
-	/* Replace nop with an ftrace call. */
-	ftrace_generate_nop_insn(&orig);
-	ftrace_generate_call_insn(&new, rec->ip);
-
-	/* Verify that the to be replaced code matches what we expect. */
-	if (memcmp(&orig, &old, sizeof(old)))
-		return -EINVAL;
-	s390_kernel_write((void *) rec->ip, &new, sizeof(new));
+	brcl_enable((void *)rec->ip);
 	return 0;
 }
 
@@ -264,22 +200,16 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
 
 void arch_ftrace_update_code(int command)
 {
-	if (ftrace_shared_hotpatch_trampoline(NULL))
-		ftrace_modify_all_code(command);
-	else
-		ftrace_run_stop_machine(command);
-}
-
-static void __ftrace_sync(void *dummy)
-{
+	ftrace_modify_all_code(command);
 }
 
 int ftrace_arch_code_modify_post_process(void)
 {
-	if (ftrace_shared_hotpatch_trampoline(NULL)) {
-		/* Send SIGP to the other CPUs, so they see the new code. */
-		smp_call_function(__ftrace_sync, NULL, 1);
-	}
+	/*
+	 * Flush any pre-fetched instructions on all
+	 * CPUs to make the new code visible.
+	 */
+	text_poke_sync_lock();
 	return 0;
 }
 
@@ -294,10 +224,6 @@ static int __init ftrace_plt_init(void)
 		panic("cannot allocate ftrace plt\n");
 
 	start = ftrace_shared_hotpatch_trampoline(&end);
-	if (!start) {
-		start = ftrace_plt_template;
-		end = ftrace_plt_template_end;
-	}
 	memcpy(ftrace_plt, start, end - start);
 	set_memory_ro((unsigned long)ftrace_plt, 1);
 	return 0;
@@ -337,12 +263,14 @@ NOKPROBE_SYMBOL(prepare_ftrace_return);
 int ftrace_enable_ftrace_graph_caller(void)
 {
 	brcl_disable(ftrace_graph_caller);
+	text_poke_sync_lock();
 	return 0;
 }
 
 int ftrace_disable_ftrace_graph_caller(void)
 {
 	brcl_enable(ftrace_graph_caller);
+	text_poke_sync_lock();
 	return 0;
 }