diff options
| author | Vegard Nossum <vegard.nossum@oracle.com> | 2016-05-21 17:46:10 +0200 |
|---|---|---|
| committer | Richard Weinberger <richard@nod.at> | 2016-08-04 00:18:06 +0200 |
| commit | 915eed20e40f4dcb142cb29a3de6f6ba67f4bb5a (patch) | |
| tree | dc606eee62b4f6ed16b456450c4cc3523aab719f | |
| parent | 8e99bc70468dcc42a756ca4b100e2fb2c30c4c89 (diff) | |
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>
| -rw-r--r-- | arch/um/Kconfig.common | 1 | ||||
| -rw-r--r-- | arch/um/kernel/Makefile | 5 | ||||
| -rw-r--r-- | arch/um/os-Linux/Makefile | 3 | ||||
| -rw-r--r-- | arch/x86/um/vdso/Makefile | 3 |
4 files changed, 12 insertions, 0 deletions
diff --git a/arch/um/Kconfig.common b/arch/um/Kconfig.common index 08d931c98621..f8530d866c9f 100644 --- a/arch/um/Kconfig.common +++ b/arch/um/Kconfig.common @@ -1,6 +1,7 @@ config UML bool default y + select ARCH_HAS_KCOV select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_SECCOMP_FILTER select HAVE_UID16 diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile index a6a5e42caaef..2f36d515762e 100644 --- a/arch/um/kernel/Makefile +++ b/arch/um/kernel/Makefile @@ -3,6 +3,11 @@ # Licensed under the GPL # +# Don't instrument UML-specific code; without this, we may crash when +# accessing the instrumentation buffer for the first time from the +# kernel. +KCOV_INSTRUMENT := n + CPPFLAGS_vmlinux.lds := -DSTART=$(LDS_START) \ -DELF_ARCH=$(LDS_ELF_ARCH) \ -DELF_FORMAT=$(LDS_ELF_FORMAT) \ diff --git a/arch/um/os-Linux/Makefile b/arch/um/os-Linux/Makefile index 08ff5094fcdd..ada473bf6f46 100644 --- a/arch/um/os-Linux/Makefile +++ b/arch/um/os-Linux/Makefile @@ -3,6 +3,9 @@ # Licensed under the GPL # +# Don't instrument UML-specific code +KCOV_INSTRUMENT := n + obj-y = aio.o execvp.o file.o helper.o irq.o main.o mem.o process.o \ registers.o sigio.o signal.o start_up.o time.o tty.o \ umid.o user_syms.o util.o drivers/ skas/ diff --git a/arch/x86/um/vdso/Makefile b/arch/x86/um/vdso/Makefile index 6c803ca49b5d..d72dec406ccb 100644 --- a/arch/x86/um/vdso/Makefile +++ b/arch/x86/um/vdso/Makefile @@ -2,6 +2,9 @@ # Building vDSO images for x86. # +# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. +KCOV_INSTRUMENT := n + VDSO64-y := y vdso-install-$(VDSO64-y) += vdso.so |