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From:   Song Liu <song@kernel.org>
To:     <bpf@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-mm@kvack.org>
CC:     <daniel@iogearbox.net>, <kernel-team@fb.com>, <x86@kernel.org>,
        <dave.hansen@linux.intel.com>, <rick.p.edgecombe@intel.com>,
        <mcgrof@kernel.org>, Song Liu <song@kernel.org>
Subject: [PATCH v6 bpf-next 3/5] vmalloc: WARN for set_vm_flush_reset_perms() on huge pages
Date:   Thu, 7 Jul 2022 15:35:44 -0700
Message-ID: <20220707223546.4124919-4-song@kernel.org>
In-Reply-To: <20220707223546.4124919-1-song@kernel.org>
References: <20220707223546.4124919-1-song@kernel.org>
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VM_FLUSH_RESET_PERMS is not yet ready for huge pages, add a WARN to
catch misuse soon.

Suggested-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Song Liu <song@kernel.org>
---
 include/linux/vmalloc.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 096d48aa3437..59d3e1f3e108 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -239,6 +239,7 @@ static inline void set_vm_flush_reset_perms(void *addr)
 {
 	struct vm_struct *vm = find_vm_area(addr);
 
+	WARN_ON_ONCE(is_vm_area_hugepages(addr));
 	if (vm)
 		vm->flags |= VM_FLUSH_RESET_PERMS;
 }
-- 
2.30.2