diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 7f2eed1fc81b284f7082ab76086bcdfa45d77dff..6461a16b45594b144f8fe2390fe42973e4fc8725 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -407,6 +407,13 @@ void hyperv_cleanup(void)
/* Reset our OS id */
wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
+ /*
+ * Reset hypercall page reference before reset the page,
+ * let hypercall operations fail safely rather than
+ * panic the kernel for using invalid hypercall page
+ */
+ hv_hypercall_pg = NULL;
+
/* Reset the hypercall page */
hypercall_msr.as_uint64 = 0;
wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
index 0ce558a8150d34fe6c3476274bae038f43a291a0..8f657286d599a9577dca86b46b8199c9c547a661 100644
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h
@@ -7,11 +7,7 @@
#endif
#ifdef CONFIG_KASAN
-#ifdef CONFIG_KASAN_EXTRA
-#define KASAN_STACK_ORDER 2
-#else
#define KASAN_STACK_ORDER 1
-#endif
#else
#define KASAN_STACK_ORDER 0
#endif
diff --git a/arch/x86/include/asm/unwind.h b/arch/x86/include/asm/unwind.h
index 1f86e1b0a5cdc1afeb4667e8c770ec81456e9fb4..499578f7e6d7bb5020fe0c503c70b1be0f5b95f1 100644
--- a/arch/x86/include/asm/unwind.h
+++ b/arch/x86/include/asm/unwind.h
@@ -23,6 +23,12 @@ struct unwind_state {
#elif defined(CONFIG_UNWINDER_FRAME_POINTER)
bool got_irq;
unsigned long *bp, *orig_sp, ip;
+ /*
+ * If non-NULL: The current frame is incomplete and doesn't contain a
+ * valid BP. When looking for the next frame, use this instead of the
+ * non-existent saved BP.
+ */
+ unsigned long *next_bp;
struct pt_regs *regs;
#else
unsigned long *sp;
diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c
index 3dc26f95d46e8a1ea439dba8ae144bae0dc9444d..9b9fd4826e7ab4e8275877a0ebeba345d5e78e3f 100644
--- a/arch/x86/kernel/unwind_frame.c
+++ b/arch/x86/kernel/unwind_frame.c
@@ -320,10 +320,14 @@ bool unwind_next_frame(struct unwind_state *state)
}
/* Get the next frame pointer: */
- if (state->regs)
+ if (state->next_bp) {
+ next_bp = state->next_bp;
+ state->next_bp = NULL;
+ } else if (state->regs) {
next_bp = (unsigned long *)state->regs->bp;
- else
+ } else {
next_bp = (unsigned long *)READ_ONCE_TASK_STACK(state->task, *state->bp);
+ }
/* Move to the next frame if it's safe: */
if (!update_stack_state(state, next_bp))
@@ -398,6 +402,21 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task,
bp = get_frame_pointer(task, regs);
+ /*
+ * If we crash with IP==0, the last successfully executed instruction
+ * was probably an indirect function call with a NULL function pointer.
+ * That means that SP points into the middle of an incomplete frame:
+ * *SP is a return pointer, and *(SP-sizeof(unsigned long)) is where we
+ * would have written a frame pointer if we hadn't crashed.
+ * Pretend that the frame is complete and that BP points to it, but save
+ * the real BP so that we can use it when looking for the next frame.
+ */
+ if (regs && regs->ip == 0 &&
+ (unsigned long *)kernel_stack_pointer(regs) >= first_frame) {
+ state->next_bp = bp;
+ bp = ((unsigned long *)kernel_stack_pointer(regs)) - 1;
+ }
+
/* Initialize stack info and make sure the frame data is accessible: */
get_stack_info(bp, state->task, &state->stack_info,
&state->stack_mask);
@@ -410,7 +429,7 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task,
*/
while (!unwind_done(state) &&
(!on_stack(&state->stack_info, first_frame, sizeof(long)) ||
- state->bp < first_frame))
+ (state->next_bp == NULL && state->bp < first_frame)))
unwind_next_frame(state);
}
EXPORT_SYMBOL_GPL(__unwind_start);
diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
index 26038eacf74a7130d659f98e5e1348667d4d635e..89be1be1790c413f2030eaee83c379c58bafde5c 100644
--- a/arch/x86/kernel/unwind_orc.c
+++ b/arch/x86/kernel/unwind_orc.c
@@ -113,6 +113,20 @@ static struct orc_entry *orc_ftrace_find(unsigned long ip)
}
#endif
+/*
+ * If we crash with IP==0, the last successfully executed instruction
+ * was probably an indirect function call with a NULL function pointer,
+ * and we don't have unwind information for NULL.
+ * This hardcoded ORC entry for IP==0 allows us to unwind from a NULL function
+ * pointer into its parent and then continue normally from there.
+ */
+static struct orc_entry null_orc_entry = {
+ .sp_offset = sizeof(long),
+ .sp_reg = ORC_REG_SP,
+ .bp_reg = ORC_REG_UNDEFINED,
+ .type = ORC_TYPE_CALL
+};
+
static struct orc_entry *orc_find(unsigned long ip)
{
static struct orc_entry *orc;
@@ -120,6 +134,9 @@ static struct orc_entry *orc_find(unsigned long ip)
if (!orc_init)
return NULL;
+ if (ip == 0)
+ return &null_orc_entry;
+
/* For non-init vmlinux addresses, use the fast lookup table: */
if (ip >= LOOKUP_START_IP && ip < LOOKUP_STOP_IP) {
unsigned int idx, start, stop;
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 14e6119838a6480d28de8c94f0a4c89273f51e7a..4c570612e24eea5bee9dd837bd12baa8dc1e5ad2 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -738,7 +738,7 @@ static int __should_split_large_page(pte_t *kpte, unsigned long address,
{
unsigned long numpages, pmask, psize, lpaddr, pfn, old_pfn;
pgprot_t old_prot, new_prot, req_prot, chk_prot;
- pte_t new_pte, old_pte, *tmp;
+ pte_t new_pte, *tmp;
enum pg_level level;
/*
@@ -781,7 +781,7 @@ static int __should_split_large_page(pte_t *kpte, unsigned long address,
* Convert protection attributes to 4k-format, as cpa->mask* are set
* up accordingly.
*/
- old_pte = *kpte;
+
/* Clear PSE (aka _PAGE_PAT) and move PAT bit to correct position */
req_prot = pgprot_large_2_4k(old_prot);
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 3d7a6a9c2370ebef7f68cd53a8cba542ac98097b..f8f6f04c445379fbe9344931ce0fb0d2754c4442 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -733,7 +733,7 @@
KEEP(*(.orc_unwind_ip)) \
__stop_orc_unwind_ip = .; \
} \
- . = ALIGN(6); \
+ . = ALIGN(2); \
.orc_unwind : AT(ADDR(.orc_unwind) - LOAD_OFFSET) { \
__start_orc_unwind = .; \
KEEP(*(.orc_unwind)) \