[PATCH 4.9 054/102] arm64: mm: Invalidate both kernel and user ASIDs when performing TLBI

From: Greg Kroah-Hartman
Date: Fri Apr 06 2018 - 10:40:11 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Will Deacon <will.deacon@xxxxxxx>

commit 9b0de864b5bc upstream.

Since an mm has both a kernel and a user ASID, we need to ensure that
broadcast TLB maintenance targets both address spaces so that things
like CoW continue to work with the uaccess primitives in the kernel.

Reviewed-by: Mark Rutland <mark.rutland@xxxxxxx>
Tested-by: Laura Abbott <labbott@xxxxxxxxxx>
Tested-by: Shanker Donthineni <shankerd@xxxxxxxxxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxx> [v4.9 backport]
Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx> [v4.9 backport]
Tested-by: Will Deacon <will.deacon@xxxxxxx>
Tested-by: Greg Hackmann <ghackmann@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/include/asm/tlbflush.h | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)

--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -23,6 +23,7 @@

#include <linux/sched.h>
#include <asm/cputype.h>
+#include <asm/mmu.h>

/*
* Raw TLBI operations.
@@ -42,6 +43,11 @@

#define __tlbi(op, ...) __TLBI_N(op, ##__VA_ARGS__, 1, 0)

+#define __tlbi_user(op, arg) do { \
+ if (arm64_kernel_unmapped_at_el0()) \
+ __tlbi(op, (arg) | USER_ASID_FLAG); \
+} while (0)
+
/*
* TLB Management
* ==============
@@ -103,6 +109,7 @@ static inline void flush_tlb_mm(struct m

dsb(ishst);
__tlbi(aside1is, asid);
+ __tlbi_user(aside1is, asid);
dsb(ish);
}

@@ -113,6 +120,7 @@ static inline void flush_tlb_page(struct

dsb(ishst);
__tlbi(vale1is, addr);
+ __tlbi_user(vale1is, addr);
dsb(ish);
}

@@ -139,10 +147,13 @@ static inline void __flush_tlb_range(str

dsb(ishst);
for (addr = start; addr < end; addr += 1 << (PAGE_SHIFT - 12)) {
- if (last_level)
+ if (last_level) {
__tlbi(vale1is, addr);
- else
+ __tlbi_user(vale1is, addr);
+ } else {
__tlbi(vae1is, addr);
+ __tlbi_user(vae1is, addr);
+ }
}
dsb(ish);
}
@@ -182,6 +193,7 @@ static inline void __flush_tlb_pgtable(s
unsigned long addr = uaddr >> 12 | (ASID(mm) << 48);

__tlbi(vae1is, addr);
+ __tlbi_user(vae1is, addr);
dsb(ish);
}