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authorVegard Nossum <vegard.nossum@oracle.com>2016-05-21 17:46:10 +0200
committerRichard Weinberger <richard@nod.at>2016-08-04 00:18:06 +0200
commit915eed20e40f4dcb142cb29a3de6f6ba67f4bb5a (patch)
treedc606eee62b4f6ed16b456450c4cc3523aab719f /arch/x86
parent8e99bc70468dcc42a756ca4b100e2fb2c30c4c89 (diff)
downloadlinux-915eed20e40f4dcb142cb29a3de6f6ba67f4bb5a.tar.gz
um: Support kcov
This adds support for kcov to UML.

There is a small problem where UML will randomly segfault during boot;
this is because current_thread_info() occasionally returns an invalid
(non-NULL) pointer and we try to dereference it in
__sanitizer_cov_trace_pc(). I consider this a bug in UML itself and this
patch merely exposes it.

[v2: disable instrumentation in UML-specific code]

Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Meyer <thomas@m3y3r.de>
Cc: user-mode-linux-devel <user-mode-linux-devel@lists.sourceforge.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/um/vdso/Makefile3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/um/vdso/Makefile b/arch/x86/um/vdso/Makefile
index 6c803ca49b5d..d72dec406ccb 100644
--- a/arch/x86/um/vdso/Makefile
+++ b/arch/x86/um/vdso/Makefile
@@ -2,6 +2,9 @@
 # Building vDSO images for x86.
 #
 
+# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
+KCOV_INSTRUMENT                := n
+
 VDSO64-y		:= y
 
 vdso-install-$(VDSO64-y)	+= vdso.so