aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/arch/x86/kernel
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/apic/apic.c27
-rw-r--r--arch/x86/kernel/dumpstack_64.c3
-rw-r--r--arch/x86/kernel/ftrace.c29
-rw-r--r--arch/x86/kernel/unwind_frame.c3
-rw-r--r--arch/x86/kernel/unwind_orc.c113
5 files changed, 121 insertions, 54 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 81b9c63dae1b..e53dda210cd7 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -352,8 +352,6 @@ static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
* According to Intel, MFENCE can do the serialization here.
*/
asm volatile("mfence" : : : "memory");
-
- printk_once(KERN_DEBUG "TSC deadline timer enabled\n");
return;
}
@@ -546,7 +544,7 @@ static struct clock_event_device lapic_clockevent = {
};
static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
-static u32 hsx_deadline_rev(void)
+static __init u32 hsx_deadline_rev(void)
{
switch (boot_cpu_data.x86_stepping) {
case 0x02: return 0x3a; /* EP */
@@ -556,7 +554,7 @@ static u32 hsx_deadline_rev(void)
return ~0U;
}
-static u32 bdx_deadline_rev(void)
+static __init u32 bdx_deadline_rev(void)
{
switch (boot_cpu_data.x86_stepping) {
case 0x02: return 0x00000011;
@@ -568,7 +566,7 @@ static u32 bdx_deadline_rev(void)
return ~0U;
}
-static u32 skx_deadline_rev(void)
+static __init u32 skx_deadline_rev(void)
{
switch (boot_cpu_data.x86_stepping) {
case 0x03: return 0x01000136;
@@ -581,7 +579,7 @@ static u32 skx_deadline_rev(void)
return ~0U;
}
-static const struct x86_cpu_id deadline_match[] = {
+static const struct x86_cpu_id deadline_match[] __initconst = {
X86_MATCH_INTEL_FAM6_MODEL( HASWELL_X, &hsx_deadline_rev),
X86_MATCH_INTEL_FAM6_MODEL( BROADWELL_X, 0x0b000020),
X86_MATCH_INTEL_FAM6_MODEL( BROADWELL_D, &bdx_deadline_rev),
@@ -603,18 +601,19 @@ static const struct x86_cpu_id deadline_match[] = {
{},
};
-static void apic_check_deadline_errata(void)
+static __init bool apic_validate_deadline_timer(void)
{
const struct x86_cpu_id *m;
u32 rev;
- if (!boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER) ||
- boot_cpu_has(X86_FEATURE_HYPERVISOR))
- return;
+ if (!boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
+ return false;
+ if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
+ return true;
m = x86_match_cpu(deadline_match);
if (!m)
- return;
+ return true;
/*
* Function pointers will have the MSB set due to address layout,
@@ -626,11 +625,12 @@ static void apic_check_deadline_errata(void)
rev = (u32)m->driver_data;
if (boot_cpu_data.microcode >= rev)
- return;
+ return true;
setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
pr_err(FW_BUG "TSC_DEADLINE disabled due to Errata; "
"please update microcode to version: 0x%x (or later)\n", rev);
+ return false;
}
/*
@@ -2092,7 +2092,8 @@ void __init init_apic_mappings(void)
{
unsigned int new_apicid;
- apic_check_deadline_errata();
+ if (apic_validate_deadline_timer())
+ pr_debug("TSC deadline timer available\n");
if (x2apic_mode) {
boot_cpu_physical_apicid = read_apic_id();
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 87b97897a881..460ae7f66818 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -183,7 +183,8 @@ recursion_check:
*/
if (visit_mask) {
if (*visit_mask & (1UL << info->type)) {
- printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);
+ if (task == current)
+ printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);
goto unknown;
}
*visit_mask |= 1UL << info->type;
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 37a0aeaf89e7..b0e641793be4 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -407,7 +407,8 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
set_vm_flush_reset_perms(trampoline);
- set_memory_ro((unsigned long)trampoline, npages);
+ if (likely(system_state != SYSTEM_BOOTING))
+ set_memory_ro((unsigned long)trampoline, npages);
set_memory_x((unsigned long)trampoline, npages);
return (unsigned long)trampoline;
fail:
@@ -415,6 +416,32 @@ fail:
return 0;
}
+void set_ftrace_ops_ro(void)
+{
+ struct ftrace_ops *ops;
+ unsigned long start_offset;
+ unsigned long end_offset;
+ unsigned long npages;
+ unsigned long size;
+
+ do_for_each_ftrace_op(ops, ftrace_ops_list) {
+ if (!(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP))
+ continue;
+
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
+ start_offset = (unsigned long)ftrace_regs_caller;
+ end_offset = (unsigned long)ftrace_regs_caller_end;
+ } else {
+ start_offset = (unsigned long)ftrace_caller;
+ end_offset = (unsigned long)ftrace_epilogue;
+ }
+ size = end_offset - start_offset;
+ size = size + RET_SIZE + sizeof(void *);
+ npages = DIV_ROUND_UP(size, PAGE_SIZE);
+ set_memory_ro((unsigned long)ops->trampoline, npages);
+ } while_for_each_ftrace_op(ops);
+}
+
static unsigned long calc_trampoline_call_offset(bool save_regs)
{
unsigned long start_offset;
diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c
index a224b5ab103f..54226110bc7f 100644
--- a/arch/x86/kernel/unwind_frame.c
+++ b/arch/x86/kernel/unwind_frame.c
@@ -344,6 +344,9 @@ bad_address:
if (IS_ENABLED(CONFIG_X86_32))
goto the_end;
+ if (state->task != current)
+ goto the_end;
+
if (state->regs) {
printk_deferred_once(KERN_WARNING
"WARNING: kernel stack regs at %p in %s:%d has bad 'bp' value %p\n",
diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
index e9cc182aa97e..5b0bd8581fe6 100644
--- a/arch/x86/kernel/unwind_orc.c
+++ b/arch/x86/kernel/unwind_orc.c
@@ -8,19 +8,21 @@
#include <asm/orc_lookup.h>
#define orc_warn(fmt, ...) \
- printk_deferred_once(KERN_WARNING pr_fmt("WARNING: " fmt), ##__VA_ARGS__)
+ printk_deferred_once(KERN_WARNING "WARNING: " fmt, ##__VA_ARGS__)
+
+#define orc_warn_current(args...) \
+({ \
+ if (state->task == current) \
+ orc_warn(args); \
+})
extern int __start_orc_unwind_ip[];
extern int __stop_orc_unwind_ip[];
extern struct orc_entry __start_orc_unwind[];
extern struct orc_entry __stop_orc_unwind[];
-static DEFINE_MUTEX(sort_mutex);
-int *cur_orc_ip_table = __start_orc_unwind_ip;
-struct orc_entry *cur_orc_table = __start_orc_unwind;
-
-unsigned int lookup_num_blocks;
-bool orc_init;
+static bool orc_init __ro_after_init;
+static unsigned int lookup_num_blocks __ro_after_init;
static inline unsigned long orc_ip(const int *ip)
{
@@ -142,9 +144,6 @@ static struct orc_entry *orc_find(unsigned long ip)
{
static struct orc_entry *orc;
- if (!orc_init)
- return NULL;
-
if (ip == 0)
return &null_orc_entry;
@@ -189,6 +188,10 @@ static struct orc_entry *orc_find(unsigned long ip)
#ifdef CONFIG_MODULES
+static DEFINE_MUTEX(sort_mutex);
+static int *cur_orc_ip_table = __start_orc_unwind_ip;
+static struct orc_entry *cur_orc_table = __start_orc_unwind;
+
static void orc_sort_swap(void *_a, void *_b, int size)
{
struct orc_entry *orc_a, *orc_b;
@@ -381,9 +384,38 @@ static bool deref_stack_iret_regs(struct unwind_state *state, unsigned long addr
return true;
}
+/*
+ * If state->regs is non-NULL, and points to a full pt_regs, just get the reg
+ * value from state->regs.
+ *
+ * Otherwise, if state->regs just points to IRET regs, and the previous frame
+ * had full regs, it's safe to get the value from the previous regs. This can
+ * happen when early/late IRQ entry code gets interrupted by an NMI.
+ */
+static bool get_reg(struct unwind_state *state, unsigned int reg_off,
+ unsigned long *val)
+{
+ unsigned int reg = reg_off/8;
+
+ if (!state->regs)
+ return false;
+
+ if (state->full_regs) {
+ *val = ((unsigned long *)state->regs)[reg];
+ return true;
+ }
+
+ if (state->prev_regs) {
+ *val = ((unsigned long *)state->prev_regs)[reg];
+ return true;
+ }
+
+ return false;
+}
+
bool unwind_next_frame(struct unwind_state *state)
{
- unsigned long ip_p, sp, orig_ip = state->ip, prev_sp = state->sp;
+ unsigned long ip_p, sp, tmp, orig_ip = state->ip, prev_sp = state->sp;
enum stack_type prev_type = state->stack_info.type;
struct orc_entry *orc;
bool indirect = false;
@@ -445,43 +477,39 @@ bool unwind_next_frame(struct unwind_state *state)
break;
case ORC_REG_R10:
- if (!state->regs || !state->full_regs) {
- orc_warn("missing regs for base reg R10 at ip %pB\n",
- (void *)state->ip);
+ if (!get_reg(state, offsetof(struct pt_regs, r10), &sp)) {
+ orc_warn_current("missing R10 value at %pB\n",
+ (void *)state->ip);
goto err;
}
- sp = state->regs->r10;
break;
case ORC_REG_R13:
- if (!state->regs || !state->full_regs) {
- orc_warn("missing regs for base reg R13 at ip %pB\n",
- (void *)state->ip);
+ if (!get_reg(state, offsetof(struct pt_regs, r13), &sp)) {
+ orc_warn_current("missing R13 value at %pB\n",
+ (void *)state->ip);
goto err;
}
- sp = state->regs->r13;
break;
case ORC_REG_DI:
- if (!state->regs || !state->full_regs) {
- orc_warn("missing regs for base reg DI at ip %pB\n",
- (void *)state->ip);
+ if (!get_reg(state, offsetof(struct pt_regs, di), &sp)) {
+ orc_warn_current("missing RDI value at %pB\n",
+ (void *)state->ip);
goto err;
}
- sp = state->regs->di;
break;
case ORC_REG_DX:
- if (!state->regs || !state->full_regs) {
- orc_warn("missing regs for base reg DX at ip %pB\n",
- (void *)state->ip);
+ if (!get_reg(state, offsetof(struct pt_regs, dx), &sp)) {
+ orc_warn_current("missing DX value at %pB\n",
+ (void *)state->ip);
goto err;
}
- sp = state->regs->dx;
break;
default:
- orc_warn("unknown SP base reg %d for ip %pB\n",
+ orc_warn("unknown SP base reg %d at %pB\n",
orc->sp_reg, (void *)state->ip);
goto err;
}
@@ -504,44 +532,48 @@ bool unwind_next_frame(struct unwind_state *state)
state->sp = sp;
state->regs = NULL;
+ state->prev_regs = NULL;
state->signal = false;
break;
case ORC_TYPE_REGS:
if (!deref_stack_regs(state, sp, &state->ip, &state->sp)) {
- orc_warn("can't dereference registers at %p for ip %pB\n",
- (void *)sp, (void *)orig_ip);
+ orc_warn_current("can't access registers at %pB\n",
+ (void *)orig_ip);
goto err;
}
state->regs = (struct pt_regs *)sp;
+ state->prev_regs = NULL;
state->full_regs = true;
state->signal = true;
break;
case ORC_TYPE_REGS_IRET:
if (!deref_stack_iret_regs(state, sp, &state->ip, &state->sp)) {
- orc_warn("can't dereference iret registers at %p for ip %pB\n",
- (void *)sp, (void *)orig_ip);
+ orc_warn_current("can't access iret registers at %pB\n",
+ (void *)orig_ip);
goto err;
}
+ if (state->full_regs)
+ state->prev_regs = state->regs;
state->regs = (void *)sp - IRET_FRAME_OFFSET;
state->full_regs = false;
state->signal = true;
break;
default:
- orc_warn("unknown .orc_unwind entry type %d for ip %pB\n",
+ orc_warn("unknown .orc_unwind entry type %d at %pB\n",
orc->type, (void *)orig_ip);
- break;
+ goto err;
}
/* Find BP: */
switch (orc->bp_reg) {
case ORC_REG_UNDEFINED:
- if (state->regs && state->full_regs)
- state->bp = state->regs->bp;
+ if (get_reg(state, offsetof(struct pt_regs, bp), &tmp))
+ state->bp = tmp;
break;
case ORC_REG_PREV_SP:
@@ -564,8 +596,8 @@ bool unwind_next_frame(struct unwind_state *state)
if (state->stack_info.type == prev_type &&
on_stack(&state->stack_info, (void *)state->sp, sizeof(long)) &&
state->sp <= prev_sp) {
- orc_warn("stack going in the wrong direction? ip=%pB\n",
- (void *)orig_ip);
+ orc_warn_current("stack going in the wrong direction? at %pB\n",
+ (void *)orig_ip);
goto err;
}
@@ -585,6 +617,9 @@ EXPORT_SYMBOL_GPL(unwind_next_frame);
void __unwind_start(struct unwind_state *state, struct task_struct *task,
struct pt_regs *regs, unsigned long *first_frame)
{
+ if (!orc_init)
+ goto done;
+
memset(state, 0, sizeof(*state));
state->task = task;
@@ -651,7 +686,7 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task,
/* Otherwise, skip ahead to the user-specified starting frame: */
while (!unwind_done(state) &&
(!on_stack(&state->stack_info, first_frame, sizeof(long)) ||
- state->sp <= (unsigned long)first_frame))
+ state->sp < (unsigned long)first_frame))
unwind_next_frame(state);
return;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.