Merge tag 's390-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Vasily Gorbik:

 - Raise minimum supported machine generation to z10, which comes with
   various cleanups and code simplifications (usercopy/spectre
   mitigation/etc).

 - Rework extables and get rid of anonymous out-of-line fixups.

 - Page table helpers cleanup. Add set_pXd()/set_pte() helper functions.
   Covert pte_val()/pXd_val() macros to functions.

 - Optimize kretprobe handling by avoiding extra kprobe on
   __kretprobe_trampoline.

 - Add support for CEX8 crypto cards.

 - Allow to trigger AP bus rescan via writing to /sys/bus/ap/scans.

 - Add CONFIG_EXPOLINE_EXTERN option to build the kernel without COMDAT
   group sections which simplifies kpatch support.

 - Always use the packed stack layout and extend kernel unwinder tests.

 - Add sanity checks for ftrace code patching.

 - Add s390dbf debug log for the vfio_ap device driver.

 - Various virtual vs physical address confusion fixes.

 - Various small fixes and improvements all over the code.

* tag 's390-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (69 commits)
  s390/test_unwind: add kretprobe tests
  s390/kprobes: Avoid additional kprobe in kretprobe handling
  s390: convert ".insn" encoding to instruction names
  s390: assume stckf is always present
  s390/nospec: move to single register thunks
  s390: raise minimum supported machine generation to z10
  s390/uaccess: Add copy_from/to_user_key functions
  s390/nospec: align and size extern thunks
  s390/nospec: add an option to use thunk-extern
  s390/nospec: generate single register thunks if possible
  s390/pci: make zpci_set_irq()/zpci_clear_irq() static
  s390: remove unused expoline to BC instructions
  s390/irq: use assignment instead of cast
  s390/traps: get rid of magic cast for per code
  s390/traps: get rid of magic cast for program interruption code
  s390/signal: fix typo in comments
  s390/asm-offsets: remove unused defines
  s390/test_unwind: avoid build warning with W=1
  s390: remove .fixup section
  s390/bpf: encode register within extable entry
  ...

1 files changed, 5 insertions, 26 deletions

diff --git a/arch/s390/kernel/nospec-branch.c b/arch/s390/kernel/nospec-branch.c
index 60e6fec27bba..717bbcc056e5 100644
--- a/arch/s390/kernel/nospec-branch.c
+++ b/arch/s390/kernel/nospec-branch.c
@@ -105,6 +105,7 @@ static void __init_or_module __nospec_revert(s32 *start, s32 *end)
 	s32 *epo;
 
 	/* Second part of the instruction replace is always a nop */
+	memcpy(insnbuf + 2, branch, sizeof(branch));
 	for (epo = start; epo < end; epo++) {
 		instr = (u8 *) epo + *epo;
 		if (instr[0] == 0xc0 && (instr[1] & 0x0f) == 0x04)
@@ -117,42 +118,20 @@ static void __init_or_module __nospec_revert(s32 *start, s32 *end)
 		if (thunk[0] == 0xc6 && thunk[1] == 0x00)
 			/* exrl %r0,<target-br> */
 			br = thunk + (*(int *)(thunk + 2)) * 2;
-		else if (thunk[0] == 0xc0 && (thunk[1] & 0x0f) == 0x00 &&
-			 thunk[6] == 0x44 && thunk[7] == 0x00 &&
-			 (thunk[8] & 0x0f) == 0x00 && thunk[9] == 0x00 &&
-			 (thunk[1] & 0xf0) == (thunk[8] & 0xf0))
-			/* larl %rx,<target br> + ex %r0,0(%rx) */
-			br = thunk + (*(int *)(thunk + 2)) * 2;
 		else
 			continue;
-		/* Check for unconditional branch 0x07f? or 0x47f???? */
-		if ((br[0] & 0xbf) != 0x07 || (br[1] & 0xf0) != 0xf0)
+		if (br[0] != 0x07 || (br[1] & 0xf0) != 0xf0)
 			continue;
-
-		memcpy(insnbuf + 2, branch, sizeof(branch));
 		switch (type) {
 		case BRCL_EXPOLINE:
+			/* brcl to thunk, replace with br + nop */
 			insnbuf[0] = br[0];
 			insnbuf[1] = (instr[1] & 0xf0) | (br[1] & 0x0f);
-			if (br[0] == 0x47) {
-				/* brcl to b, replace with bc + nopr */
-				insnbuf[2] = br[2];
-				insnbuf[3] = br[3];
-			} else {
-				/* brcl to br, replace with bcr + nop */
-			}
 			break;
 		case BRASL_EXPOLINE:
+			/* brasl to thunk, replace with basr + nop */
+			insnbuf[0] = 0x0d;
 			insnbuf[1] = (instr[1] & 0xf0) | (br[1] & 0x0f);
-			if (br[0] == 0x47) {
-				/* brasl to b, replace with bas + nopr */
-				insnbuf[0] = 0x4d;
-				insnbuf[2] = br[2];
-				insnbuf[3] = br[3];
-			} else {
-				/* brasl to br, replace with basr + nop */
-				insnbuf[0] = 0x0d;
-			}
 			break;
 		}