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-rw-r--r--kernel/unwind/deferred.c44
-rw-r--r--kernel/unwind/user.c59
2 files changed, 72 insertions, 31 deletions
diff --git a/kernel/unwind/deferred.c b/kernel/unwind/deferred.c
index dc6040aae3ee..a88fb481c4a3 100644
--- a/kernel/unwind/deferred.c
+++ b/kernel/unwind/deferred.c
@@ -53,7 +53,7 @@ DEFINE_STATIC_SRCU(unwind_srcu);
static inline bool unwind_pending(struct unwind_task_info *info)
{
- return test_bit(UNWIND_PENDING_BIT, &info->unwind_mask);
+ return atomic_long_read(&info->unwind_mask) & UNWIND_PENDING;
}
/*
@@ -79,6 +79,8 @@ static u64 get_cookie(struct unwind_task_info *info)
{
u32 cnt = 1;
+ lockdep_assert_irqs_disabled();
+
if (info->id.cpu)
return info->id.id;
@@ -126,23 +128,20 @@ int unwind_user_faultable(struct unwind_stacktrace *trace)
cache = info->cache;
trace->entries = cache->entries;
-
- if (cache->nr_entries) {
- /*
- * The user stack has already been previously unwound in this
- * entry context. Skip the unwind and use the cache.
- */
- trace->nr = cache->nr_entries;
+ trace->nr = cache->nr_entries;
+ /*
+ * The user stack has already been previously unwound in this
+ * entry context. Skip the unwind and use the cache.
+ */
+ if (trace->nr)
return 0;
- }
- trace->nr = 0;
unwind_user(trace, UNWIND_MAX_ENTRIES);
cache->nr_entries = trace->nr;
/* Clear nr_entries on way back to user space */
- set_bit(UNWIND_USED_BIT, &info->unwind_mask);
+ atomic_long_or(UNWIND_USED, &info->unwind_mask);
return 0;
}
@@ -160,7 +159,7 @@ static void process_unwind_deferred(struct task_struct *task)
/* Clear pending bit but make sure to have the current bits */
bits = atomic_long_fetch_andnot(UNWIND_PENDING,
- (atomic_long_t *)&info->unwind_mask);
+ &info->unwind_mask);
/*
* From here on out, the callback must always be called, even if it's
* just an empty trace.
@@ -231,6 +230,7 @@ void unwind_deferred_task_exit(struct task_struct *task)
int unwind_deferred_request(struct unwind_work *work, u64 *cookie)
{
struct unwind_task_info *info = &current->unwind_info;
+ int twa_mode = TWA_RESUME;
unsigned long old, bits;
unsigned long bit;
int ret;
@@ -246,8 +246,11 @@ int unwind_deferred_request(struct unwind_work *work, u64 *cookie)
* Trigger a warning to make it obvious that an architecture
* is using this in NMI when it should not be.
*/
- if (WARN_ON_ONCE(!CAN_USE_IN_NMI && in_nmi()))
- return -EINVAL;
+ if (in_nmi()) {
+ if (WARN_ON_ONCE(!CAN_USE_IN_NMI))
+ return -EINVAL;
+ twa_mode = TWA_NMI_CURRENT;
+ }
/* Do not allow cancelled works to request again */
bit = READ_ONCE(work->bit);
@@ -261,7 +264,7 @@ int unwind_deferred_request(struct unwind_work *work, u64 *cookie)
*cookie = get_cookie(info);
- old = READ_ONCE(info->unwind_mask);
+ old = atomic_long_read(&info->unwind_mask);
/* Is this already queued or executed */
if (old & bit)
@@ -274,7 +277,7 @@ int unwind_deferred_request(struct unwind_work *work, u64 *cookie)
* to have a callback.
*/
bits = UNWIND_PENDING | bit;
- old = atomic_long_fetch_or(bits, (atomic_long_t *)&info->unwind_mask);
+ old = atomic_long_fetch_or(bits, &info->unwind_mask);
if (old & bits) {
/*
* If the work's bit was set, whatever set it had better
@@ -285,10 +288,10 @@ int unwind_deferred_request(struct unwind_work *work, u64 *cookie)
}
/* The work has been claimed, now schedule it. */
- ret = task_work_add(current, &info->work, TWA_RESUME);
+ ret = task_work_add(current, &info->work, twa_mode);
if (WARN_ON_ONCE(ret))
- WRITE_ONCE(info->unwind_mask, 0);
+ atomic_long_set(&info->unwind_mask, 0);
return ret;
}
@@ -320,7 +323,8 @@ void unwind_deferred_cancel(struct unwind_work *work)
guard(rcu)();
/* Clear this bit from all threads */
for_each_process_thread(g, t) {
- clear_bit(bit, &t->unwind_info.unwind_mask);
+ atomic_long_andnot(BIT(bit),
+ &t->unwind_info.unwind_mask);
if (t->unwind_info.cache)
clear_bit(bit, &t->unwind_info.cache->unwind_completed);
}
@@ -350,7 +354,7 @@ void unwind_task_init(struct task_struct *task)
memset(info, 0, sizeof(*info));
init_task_work(&info->work, unwind_deferred_task_work);
- info->unwind_mask = 0;
+ atomic_long_set(&info->unwind_mask, 0);
}
void unwind_task_free(struct task_struct *task)
diff --git a/kernel/unwind/user.c b/kernel/unwind/user.c
index 97a8415e3216..39e270789444 100644
--- a/kernel/unwind/user.c
+++ b/kernel/unwind/user.c
@@ -8,18 +8,28 @@
#include <linux/unwind_user.h>
#include <linux/uaccess.h>
-static const struct unwind_user_frame fp_frame = {
- ARCH_INIT_USER_FP_FRAME
-};
-
#define for_each_user_frame(state) \
for (unwind_user_start(state); !(state)->done; unwind_user_next(state))
-static int unwind_user_next_fp(struct unwind_user_state *state)
+static inline int
+get_user_word(unsigned long *word, unsigned long base, int off, unsigned int ws)
+{
+ unsigned long __user *addr = (void __user *)base + off;
+#ifdef CONFIG_COMPAT
+ if (ws == sizeof(int)) {
+ unsigned int data;
+ int ret = get_user(data, (unsigned int __user *)addr);
+ *word = data;
+ return ret;
+ }
+#endif
+ return get_user(*word, addr);
+}
+
+static int unwind_user_next_common(struct unwind_user_state *state,
+ const struct unwind_user_frame *frame)
{
- const struct unwind_user_frame *frame = &fp_frame;
unsigned long cfa, fp, ra;
- unsigned int shift;
if (frame->use_fp) {
if (state->fp < state->sp)
@@ -37,24 +47,45 @@ static int unwind_user_next_fp(struct unwind_user_state *state)
return -EINVAL;
/* Make sure that the address is word aligned */
- shift = sizeof(long) == 4 ? 2 : 3;
- if (cfa & ((1 << shift) - 1))
+ if (cfa & (state->ws - 1))
return -EINVAL;
/* Find the Return Address (RA) */
- if (get_user(ra, (unsigned long *)(cfa + frame->ra_off)))
+ if (get_user_word(&ra, cfa, frame->ra_off, state->ws))
return -EINVAL;
- if (frame->fp_off && get_user(fp, (unsigned long __user *)(cfa + frame->fp_off)))
+ if (frame->fp_off && get_user_word(&fp, cfa, frame->fp_off, state->ws))
return -EINVAL;
state->ip = ra;
state->sp = cfa;
if (frame->fp_off)
state->fp = fp;
+ state->topmost = false;
return 0;
}
+static int unwind_user_next_fp(struct unwind_user_state *state)
+{
+#ifdef CONFIG_HAVE_UNWIND_USER_FP
+ struct pt_regs *regs = task_pt_regs(current);
+
+ if (state->topmost && unwind_user_at_function_start(regs)) {
+ const struct unwind_user_frame fp_entry_frame = {
+ ARCH_INIT_USER_FP_ENTRY_FRAME(state->ws)
+ };
+ return unwind_user_next_common(state, &fp_entry_frame);
+ }
+
+ const struct unwind_user_frame fp_frame = {
+ ARCH_INIT_USER_FP_FRAME(state->ws)
+ };
+ return unwind_user_next_common(state, &fp_frame);
+#else
+ return -EINVAL;
+#endif
+}
+
static int unwind_user_next(struct unwind_user_state *state)
{
unsigned long iter_mask = state->available_types;
@@ -102,6 +133,12 @@ static int unwind_user_start(struct unwind_user_state *state)
state->ip = instruction_pointer(regs);
state->sp = user_stack_pointer(regs);
state->fp = frame_pointer(regs);
+ state->ws = unwind_user_word_size(regs);
+ if (!state->ws) {
+ state->done = true;
+ return -EINVAL;
+ }
+ state->topmost = true;
return 0;
}
generated by cgit (git 2.34.1) at 2025-12-03 18:30:30 +0000