add new system file

hc

2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c

 kernel/arch/x86/kernel/unwind_frame.c
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@@ -1,3 +1,4 @@
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+// SPDX-License-Identifier: GPL-2.0-only
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 #include <linux/sched.h>
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 #include <linux/sched/task.h>
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 #include <linux/sched/task_stack.h>
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@@ -69,26 +70,11 @@
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 	}
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 }
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-static size_t regs_size(struct pt_regs *regs)
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-{
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-	/* x86_32 regs from kernel mode are two words shorter: */
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-	if (IS_ENABLED(CONFIG_X86_32) && !user_mode(regs))
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-		return sizeof(*regs) - 2*sizeof(long);
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-
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-	return sizeof(*regs);
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-}
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-
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 static bool in_entry_code(unsigned long ip)
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 {
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 	char *addr = (char *)ip;
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-	if (addr >= __entry_text_start && addr < __entry_text_end)
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-		return true;
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-
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-	if (addr >= __irqentry_text_start && addr < __irqentry_text_end)
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-		return true;
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-
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-	return false;
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+	return addr >= __entry_text_start && addr < __entry_text_end;
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 }
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 static inline unsigned long *last_frame(struct unwind_state *state)
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@@ -197,12 +183,6 @@
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 }
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 #endif
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-#ifdef CONFIG_X86_32
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-#define KERNEL_REGS_SIZE (sizeof(struct pt_regs) - 2*sizeof(long))
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-#else
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-#define KERNEL_REGS_SIZE (sizeof(struct pt_regs))
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-#endif
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-
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 static bool update_stack_state(struct unwind_state *state,
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 			       unsigned long *next_bp)
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 {
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@@ -213,7 +193,7 @@
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 	size_t len;
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 	if (state->regs)
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-		prev_frame_end = (void *)state->regs + regs_size(state->regs);
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+		prev_frame_end = (void *)state->regs + sizeof(*state->regs);
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 	else
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 		prev_frame_end = (void *)state->bp + FRAME_HEADER_SIZE;
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@@ -221,7 +201,7 @@
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 	regs = decode_frame_pointer(next_bp);
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 	if (regs) {
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 		frame = (unsigned long *)regs;
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-		len = KERNEL_REGS_SIZE;
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+		len = sizeof(*regs);
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 		state->got_irq = true;
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 	} else {
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 		frame = next_bp;
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@@ -243,14 +223,6 @@
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 	/* Make sure it only unwinds up and doesn't overlap the prev frame: */
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 	if (state->orig_sp && state->stack_info.type == prev_type &&
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 	    frame < prev_frame_end)
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-		return false;
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-
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-	/*
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-	 * On 32-bit with user mode regs, make sure the last two regs are safe
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-	 * to access:
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-	 */
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-	if (IS_ENABLED(CONFIG_X86_32) && regs && user_mode(regs) &&
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-	    !on_stack(info, frame, len + 2*sizeof(long)))
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 		return false;
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 	/* Move state to the next frame: */
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@@ -297,13 +269,13 @@
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 		/*
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 		 * kthreads (other than the boot CPU's idle thread) have some
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 		 * partial regs at the end of their stack which were placed
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-		 * there by copy_thread_tls().  But the regs don't have any
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+		 * there by copy_thread().  But the regs don't have any
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 		 * useful information, so we can skip them.
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 		 *
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 		 * This user_mode() check is slightly broader than a PF_KTHREAD
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 		 * check because it also catches the awkward situation where a
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 		 * newly forked kthread transitions into a user task by calling
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-		 * do_execve(), which eventually clears PF_KTHREAD.
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+		 * kernel_execve(), which eventually clears PF_KTHREAD.
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 		 */
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 		if (!user_mode(regs))
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 			goto the_end;
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@@ -366,6 +338,9 @@
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 	if (IS_ENABLED(CONFIG_X86_32))
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 		goto the_end;
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+	if (state->task != current)
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+		goto the_end;
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+
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 	if (state->regs) {
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 		printk_deferred_once(KERN_WARNING
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 			"WARNING: kernel stack regs at %p in %s:%d has bad 'bp' value %p\n",
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@@ -411,10 +386,9 @@
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 	 * Pretend that the frame is complete and that BP points to it, but save
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 	 * the real BP so that we can use it when looking for the next frame.
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 	 */
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-	if (regs && regs->ip == 0 &&
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-	    (unsigned long *)kernel_stack_pointer(regs) >= first_frame) {
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+	if (regs && regs->ip == 0 && (unsigned long *)regs->sp >= first_frame) {
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 		state->next_bp = bp;
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-		bp = ((unsigned long *)kernel_stack_pointer(regs)) - 1;
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+		bp = ((unsigned long *)regs->sp) - 1;
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 	}
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 	/* Initialize stack info and make sure the frame data is accessible: */