| Message ID | 1392372698-9974-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/lib/Makefile b/lib/Makefile index 7baccfd..fc2f9ef 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -45,6 +45,7 @@ lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o lib-$(CONFIG_PERCPU_RWSEM) += percpu-rwsem.o +GCOV_PROFILE_hweight.o := n CFLAGS_hweight.o = $(subst $(quote),,$(CONFIG_ARCH_HWEIGHT_CFLAGS)) obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o
This is a note to let you know that I have just added a patch titled x86, hweight: Fix BUG when booting with CONFIG_GCOV_PROFILE_ALL=y to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 1c2a9d9f943d457957c8ea8ca8ea378bceeb4e05 Mon Sep 17 00:00:00 2001 From: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Date: Thu, 6 Feb 2014 15:58:20 +0100 Subject: x86, hweight: Fix BUG when booting with CONFIG_GCOV_PROFILE_ALL=y commit 6583327c4dd55acbbf2a6f25e775b28b3abf9a42 upstream. Commit d61931d89b, "x86: Add optimized popcnt variants" introduced compile flag -fcall-saved-rdi for lib/hweight.c. When combined with options -fprofile-arcs and -O2, this flag causes gcc to generate broken constructor code. As a result, a 64 bit x86 kernel compiled with CONFIG_GCOV_PROFILE_ALL=y prints message "gcov: could not create file" and runs into sproadic BUGs during boot. The gcc people indicate that these kinds of problems are endemic when using ad hoc calling conventions. It is therefore best to treat any file compiled with ad hoc calling conventions as an isolated environment and avoid things like profiling or coverage analysis, since those subsystems assume a "normal" calling conventions. This patch avoids the bug by excluding lib/hweight.o from coverage profiling. Reported-by: Meelis Roos <mroos@linux.ee> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/52F3A30C.7050205@linux.vnet.ibm.com Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- lib/Makefile | 1 + 1 file changed, 1 insertion(+) -- 1.8.3.2