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| author |   kettenis <kettenis@openbsd.org> | 2020-10-04 20:03:57 +0000 |
|---|---|---|
| committer | kettenis <kettenis@openbsd.org> | 2020-10-04 20:03:57 +0000 |
| commit | fe11e15c2cfedc624276549aa908e70d3b8ba0dc (patch) | |
| tree | 96c66572e1e654c0e17d4a9acf5dbae061ab105c | |
| parent | Remove outdated comment. (diff) | |
| download | wireguard-openbsd-fe11e15c2cfedc624276549aa908e70d3b8ba0dc.tar.xz wireguard-openbsd-fe11e15c2cfedc624276549aa908e70d3b8ba0dc.zip | |
Change kcopy(9) such that it does 64-bit and 32-bit copies whenever possible.
This makes sure a kcopy(9) that is a sequence of 64-bit or 32-bit values
that are properly aligned is done atomically. This is needed for kbind(2)
as it needs to update PLT/GOT entries atomically when doing lazy binding.
This seems to fix some random SIGSEGV and SIGTRAP when linking stuff with
ld.lld.
ok deraadt@, patrick@, drahn@
| -rw-r--r-- | sys/arch/arm64/arm64/copy.S | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/sys/arch/arm64/arm64/copy.S b/sys/arch/arm64/arm64/copy.S index 6bb080aece4..db2a6c393a2 100644 --- a/sys/arch/arm64/arm64/copy.S +++ b/sys/arch/arm64/arm64/copy.S @@ -1,4 +1,4 @@ -/* $OpenBSD: copy.S,v 1.7 2019/06/19 08:00:17 patrick Exp $ */ +/* $OpenBSD: copy.S,v 1.8 2020/10/04 20:03:57 kettenis Exp $ */ /* * Copyright (c) 2015 Dale Rahn <drahn@dalerahn.com> * Copyright (c) 2014 Patrick Wildt <patrick@blueri.se> @@ -163,12 +163,28 @@ ENTRY(kcopy) adr x5, .Lcopyfault str x5, [x3, #(PCB_ONFAULT)] // set handler -// This probably should be optimized -2: ldrb w6, [x0], #1 + cmp x2, #8 + b.lo .Lkcopy4 +2: ldr x6, [x0], #8 + str x6, [x1], #8 + sub x2, x2, #8 + cmp x2, #8 + b.hs 2b + +.Lkcopy4: + tbz x2, #2, .Lkcopy1 + ldr w6, [x0], #4 + str w6, [x1], #4 + sub x2, x2, #4 + +.Lkcopy1: + cbz x2, .Lkcopy0 +3: ldrb w6, [x0], #1 strb w6, [x1], #1 sub x2, x2, #1 - cbnz x2, 2b + cbnz x2, 3b +.Lkcopy0: str x4, [x3, #(PCB_ONFAULT)] // clear handler mov x0, xzr RETGUARD_CHECK(copy, x15) |