Merge tag 's390-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull more s390 updates from Alexander Gordeev:

 - Switch read and write software bits for PUDs

 - Add missing hardware bits for PUDs and PMDs

 - Generate unwind information for C modules to fix GDB unwind error for
   vDSO functions

 - Create .build-id links for unstripped vDSO files to enable vDSO
   debugging with symbols

 - Use standard stack frame layout for vDSO generated stack frames to
   manually walk stack frames without DWARF information

 - Rework perf_callchain_user() and arch_stack_walk_user() functions to
   reduce code duplication

 - Skip first stack frame when walking user stack

 - Add basic checks to identify invalid instruction pointers when
   walking stack frames

 - Introduce and use struct stack_frame_vdso_wrapper within vDSO user
   wrapper code to automatically generate an asm-offset define. Also use
   STACK_FRAME_USER_OVERHEAD instead of STACK_FRAME_OVERHEAD to document
   that the code works with user space stack

 - Clear the backchain of the extra stack frame added by the vDSO user
   wrapper code. This allows the user stack walker to detect and skip
   the non-standard stack frame. Without this an incorrect instruction
   pointer would be added to stack traces.

 - Rewrite psw_idle() function in C to ease maintenance and further
   enhancements

 - Remove get_vtimer() function and use get_cpu_timer() instead

 - Mark psw variable in __load_psw_mask() as __unitialized to avoid
   superfluous clearing of PSW

 - Remove obsolete and superfluous comment about removed TIF_FPU flag

 - Replace memzero_explicit() and kfree() with kfree_sensitive() to fix
   warnings reported by Coccinelle

 - Wipe sensitive data and all copies of protected- or secure-keys from
   stack when an IOCTL fails

 - Both do_airq_interrupt() and do_io_interrupt() functions set
   CIF_NOHZ_DELAY flag. Move it in do_io_irq() to simplify the code

 - Provide iucv_alloc_device() and iucv_release_device() helpers, which
   can be used to deduplicate more or less identical IUCV device
   allocation and release code in four different drivers

 - Make use of iucv_alloc_device() and iucv_release_device() helpers to
   get rid of quite some code and also remove a cast to an incompatible
   function (clang W=1)

 - There is no user of iucv_root outside of the core IUCV code left.
   Therefore remove the EXPORT_SYMBOL

 - __apply_alternatives() contains a runtime check which verifies that
   the size of the to be patched code area is even. Convert this to a
   compile time check

 - Increase size of buffers for sending z/VM CP DIAGNOSE X'008' commands
   from 128 to 240

 - Do not accept z/VM CP DIAGNOSE X'008' commands longer than maximally
   allowed

 - Use correct defines IPL_BP_NVME_LEN and IPL_BP0_NVME_LEN instead of
   IPL_BP_FCP_LEN and IPL_BP0_FCP_LEN ones to initialize NVMe reIPL
   block on 'scp_data' sysfs attribute update

 - Initialize the correct fields of the NVMe dump block, which were
   confused with FCP fields

 - Refactor macros for 'scp_data' (re-)IPL sysfs attribute to reduce
   code duplication

 - Introduce 'scp_data' sysfs attribute for dump IPL to allow tools such
   as dumpconf passing additional kernel command line parameters to a
   stand-alone dumper

 - Rework the CPACF query functions to use the correct RRE or RRF
   instruction formats and set instruction register fields correctly

 - Instead of calling BUG() at runtime force a link error during compile
   when a unsupported opcode is used with __cpacf_query() or
   __cpacf_check_opcode() functions

 - Fix a crash in ap_parse_bitmap_str() function on /sys/bus/ap/apmask
   or /sys/bus/ap/aqmask sysfs file update with a relative mask value

 - Fix "bindings complete" udev event which should be sent once all AP
   devices have been bound to device drivers and again when unbind/bind
   actions take place and all AP devices are bound again

 - Facility list alt_stfle_fac_list is nowhere used in the decompressor,
   therefore remove it there

 - Remove custom kprobes insn slot allocator in favour of the standard
   module_alloc() one, since kernel image and module areas are located
   within 4GB

 - Use kvcalloc() instead of kvmalloc_array() in zcrypt driver to avoid
   calling memset() with a large byte count and get rid of the sparse
   warning as result

* tag 's390-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (39 commits)
  s390/zcrypt: Use kvcalloc() instead of kvmalloc_array()
  s390/kprobes: Remove custom insn slot allocator
  s390/boot: Remove alt_stfle_fac_list from decompressor
  s390/ap: Fix bind complete udev event sent after each AP bus scan
  s390/ap: Fix crash in AP internal function modify_bitmap()
  s390/cpacf: Make use of invalid opcode produce a link error
  s390/cpacf: Split and rework cpacf query functions
  s390/ipl: Introduce sysfs attribute 'scp_data' for dump ipl
  s390/ipl: Introduce macros for (re)ipl sysfs attribute 'scp_data'
  s390/ipl: Fix incorrect initialization of nvme dump block
  s390/ipl: Fix incorrect initialization of len fields in nvme reipl block
  s390/ipl: Do not accept z/VM CP diag X'008' cmds longer than max length
  s390/ipl: Fix size of vmcmd buffers for sending z/VM CP diag X'008' cmds
  s390/alternatives: Convert runtime sanity check into compile time check
  s390/iucv: Unexport iucv_root
  tty: hvc-iucv: Make use of iucv_alloc_device()
  s390/smsgiucv_app: Make use of iucv_alloc_device()
  s390/netiucv: Make use of iucv_alloc_device()
  s390/vmlogrdr: Make use of iucv_alloc_device()
  s390/iucv: Provide iucv_alloc_device() / iucv_release_device()
  ...

1 files changed, 75 insertions, 14 deletions

diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c
index 7c294da45bf5..640363b2a105 100644
--- a/arch/s390/kernel/stacktrace.c
+++ b/arch/s390/kernel/stacktrace.c
@@ -5,6 +5,7 @@
  *  Copyright IBM Corp. 2006
  */
 
+#include <linux/perf_event.h>
 #include <linux/stacktrace.h>
 #include <linux/uaccess.h>
 #include <linux/compat.h>
@@ -62,46 +63,106 @@ int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
 	return 0;
 }
 
-void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie,
-			  const struct pt_regs *regs)
+static inline bool store_ip(stack_trace_consume_fn consume_entry, void *cookie,
+			    struct perf_callchain_entry_ctx *entry, bool perf,
+			    unsigned long ip)
+{
+#ifdef CONFIG_PERF_EVENTS
+	if (perf) {
+		if (perf_callchain_store(entry, ip))
+			return false;
+		return true;
+	}
+#endif
+	return consume_entry(cookie, ip);
+}
+
+static inline bool ip_invalid(unsigned long ip)
 {
+	/*
+	 * Perform some basic checks if an instruction address taken
+	 * from unreliable source is invalid.
+	 */
+	if (ip & 1)
+		return true;
+	if (ip < mmap_min_addr)
+		return true;
+	if (ip >= current->mm->context.asce_limit)
+		return true;
+	return false;
+}
+
+static inline bool ip_within_vdso(unsigned long ip)
+{
+	return in_range(ip, current->mm->context.vdso_base, vdso_text_size());
+}
+
+void arch_stack_walk_user_common(stack_trace_consume_fn consume_entry, void *cookie,
+				 struct perf_callchain_entry_ctx *entry,
+				 const struct pt_regs *regs, bool perf)
+{
+	struct stack_frame_vdso_wrapper __user *sf_vdso;
 	struct stack_frame_user __user *sf;
 	unsigned long ip, sp;
 	bool first = true;
 
 	if (is_compat_task())
 		return;
-	if (!consume_entry(cookie, instruction_pointer(regs)))
+	if (!current->mm)
+		return;
+	ip = instruction_pointer(regs);
+	if (!store_ip(consume_entry, cookie, entry, perf, ip))
 		return;
 	sf = (void __user *)user_stack_pointer(regs);
 	pagefault_disable();
 	while (1) {
 		if (__get_user(sp, &sf->back_chain))
 			break;
-		if (__get_user(ip, &sf->gprs[8]))
+		/*
+		 * VDSO entry code has a non-standard stack frame layout.
+		 * See VDSO user wrapper code for details.
+		 */
+		if (!sp && ip_within_vdso(ip)) {
+			sf_vdso = (void __user *)sf;
+			if (__get_user(ip, &sf_vdso->return_address))
+				break;
+			sp = (unsigned long)sf + STACK_FRAME_VDSO_OVERHEAD;
+			sf = (void __user *)sp;
+			if (__get_user(sp, &sf->back_chain))
+				break;
+		} else {
+			sf = (void __user *)sp;
+			if (__get_user(ip, &sf->gprs[8]))
+				break;
+		}
+		/* Sanity check: ABI requires SP to be 8 byte aligned. */
+		if (sp & 0x7)
 			break;
-		if (ip & 0x1) {
+		if (ip_invalid(ip)) {
 			/*
 			 * If the instruction address is invalid, and this
 			 * is the first stack frame, assume r14 has not
 			 * been written to the stack yet. Otherwise exit.
 			 */
-			if (first && !(regs->gprs[14] & 0x1))
-				ip = regs->gprs[14];
-			else
+			if (!first)
+				break;
+			ip = regs->gprs[14];
+			if (ip_invalid(ip))
 				break;
 		}
-		if (!consume_entry(cookie, ip))
-			break;
-		/* Sanity check: ABI requires SP to be aligned 8 bytes. */
-		if (!sp || sp & 0x7)
-			break;
-		sf = (void __user *)sp;
+		if (!store_ip(consume_entry, cookie, entry, perf, ip))
+			return;
 		first = false;
 	}
 	pagefault_enable();
 }
 
+void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie,
+			  const struct pt_regs *regs)
+{
+	arch_stack_walk_user_common(consume_entry, cookie, NULL, regs, false);
+}
+
 unsigned long return_address(unsigned int n)
 {
 	struct unwind_state state;