From 1753a49e266d8f0433e60d4b59f12c2b2497646a Mon Sep 17 00:00:00 2001 From: John David Anglin Date: Tue, 29 Mar 2022 18:54:36 +0000 Subject: [PATCH] parisc: Fix patch code locking and flushing [ Upstream commit a9fe7fa7d874a536e0540469f314772c054a0323 ] This change fixes the following: 1) The flags variable is not initialized. Always use raw_spin_lock_irqsave and raw_spin_unlock_irqrestore to serialize patching. 2) flush_kernel_vmap_range is primarily intended for DMA flushes. Since __patch_text_multiple is often called with interrupts disabled, it is better to directly call flush_kernel_dcache_range_asm and flush_kernel_icache_range_asm. This avoids an extra call. 3) The final call to flush_icache_range is unnecessary. Signed-off-by: John David Anglin Signed-off-by: Helge Deller Signed-off-by: Sasha Levin --- arch/parisc/kernel/patch.c | 25 +++++++++++-------------- 1 file changed, 11 insertions(+), 14 deletions(-) diff --git a/arch/parisc/kernel/patch.c b/arch/parisc/kernel/patch.c index 80a0ab372802..e59574f65e64 100644 --- a/arch/parisc/kernel/patch.c +++ b/arch/parisc/kernel/patch.c @@ -40,10 +40,7 @@ static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags, *need_unmap = 1; set_fixmap(fixmap, page_to_phys(page)); - if (flags) - raw_spin_lock_irqsave(&patch_lock, *flags); - else - __acquire(&patch_lock); + raw_spin_lock_irqsave(&patch_lock, *flags); return (void *) (__fix_to_virt(fixmap) + (uintaddr & ~PAGE_MASK)); } @@ -52,10 +49,7 @@ static void __kprobes patch_unmap(int fixmap, unsigned long *flags) { clear_fixmap(fixmap); - if (flags) - raw_spin_unlock_irqrestore(&patch_lock, *flags); - else - __release(&patch_lock); + raw_spin_unlock_irqrestore(&patch_lock, *flags); } void __kprobes __patch_text_multiple(void *addr, u32 *insn, unsigned int len) @@ -67,8 +61,9 @@ void __kprobes __patch_text_multiple(void *addr, u32 *insn, unsigned int len) int mapped; /* Make sure we don't have any aliases in cache */ - flush_kernel_vmap_range(addr, len); - flush_icache_range(start, end); + flush_kernel_dcache_range_asm(start, end); + flush_kernel_icache_range_asm(start, end); + flush_tlb_kernel_range(start, end); p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &flags, &mapped); @@ -81,8 +76,10 @@ void __kprobes __patch_text_multiple(void *addr, u32 *insn, unsigned int len) * We're crossing a page boundary, so * need to remap */ - flush_kernel_vmap_range((void *)fixmap, - (p-fixmap) * sizeof(*p)); + flush_kernel_dcache_range_asm((unsigned long)fixmap, + (unsigned long)p); + flush_tlb_kernel_range((unsigned long)fixmap, + (unsigned long)p); if (mapped) patch_unmap(FIX_TEXT_POKE0, &flags); p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &flags, @@ -90,10 +87,10 @@ void __kprobes __patch_text_multiple(void *addr, u32 *insn, unsigned int len) } } - flush_kernel_vmap_range((void *)fixmap, (p-fixmap) * sizeof(*p)); + flush_kernel_dcache_range_asm((unsigned long)fixmap, (unsigned long)p); + flush_tlb_kernel_range((unsigned long)fixmap, (unsigned long)p); if (mapped) patch_unmap(FIX_TEXT_POKE0, &flags); - flush_icache_range(start, end); } void __kprobes __patch_text(void *addr, u32 insn)