change wifi driver to cypress

hc

2024-01-05 071106ecf68c401173c58808b1cf5f68cc50d390

 kernel/arch/riscv/kernel/patch.c
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@@ -11,6 +11,7 @@
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 #include <asm/kprobes.h>
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 #include <asm/cacheflush.h>
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 #include <asm/fixmap.h>
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+#include <asm/ftrace.h>
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 #include <asm/patch.h>
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 struct patch_insn {
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@@ -18,6 +19,8 @@
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 	u32 insn;
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 	atomic_t cpu_count;
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 };
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+
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+int riscv_patch_in_stop_machine = false;
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 #ifdef CONFIG_MMU
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 static void *patch_map(void *addr, int fixmap)
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@@ -55,8 +58,15 @@
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 	 * Before reaching here, it was expected to lock the text_mutex
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 	 * already, so we don't need to give another lock here and could
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 	 * ensure that it was safe between each cores.
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+	 *
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+	 * We're currently using stop_machine() for ftrace & kprobes, and while
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+	 * that ensures text_mutex is held before installing the mappings it
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+	 * does not ensure text_mutex is held by the calling thread.  That's
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+	 * safe but triggers a lockdep failure, so just elide it for that
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+	 * specific case.
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 	 */
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-	lockdep_assert_held(&text_mutex);
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+	if (!riscv_patch_in_stop_machine)
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+		lockdep_assert_held(&text_mutex);
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 	if (across_pages)
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 		patch_map(addr + len, FIX_TEXT_POKE1);
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@@ -117,13 +127,25 @@
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 int patch_text(void *addr, u32 insn)
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 {
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+	int ret;
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 	struct patch_insn patch = {
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 		.addr = addr,
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 		.insn = insn,
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 		.cpu_count = ATOMIC_INIT(0),
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 	};
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-	return stop_machine_cpuslocked(patch_text_cb,
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-				       &patch, cpu_online_mask);
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+	/*
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+	 * kprobes takes text_mutex, before calling patch_text(), but as we call
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+	 * calls stop_machine(), the lockdep assertion in patch_insn_write()
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+	 * gets confused by the context in which the lock is taken.
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+	 * Instead, ensure the lock is held before calling stop_machine(), and
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+	 * set riscv_patch_in_stop_machine to skip the check in
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+	 * patch_insn_write().
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+	 */
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+	lockdep_assert_held(&text_mutex);
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+	riscv_patch_in_stop_machine = true;
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+	ret = stop_machine_cpuslocked(patch_text_cb, &patch, cpu_online_mask);
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+	riscv_patch_in_stop_machine = false;
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+	return ret;
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 }
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 NOKPROBE_SYMBOL(patch_text);