On Tue, May 14, 2019 at 09:50:04AM +0200, Greg Kroah-Hartman wrote:
> On Tue, May 14, 2019 at 04:34:29PM +0900, Nobuhiro Iwamatsu wrote:
> > From: Alistair Strachan <astrachan@xxxxxxxxxx>
> >
> > commit cd01544a268ad8ee5b1dfe42c4393f1095f86879 upstream.
> >
> > Commit
> >
> > 379d98ddf413 ("x86: vdso: Use $LD instead of $CC to link")
> >
> > accidentally broke unwinding from userspace, because ld would strip the
> > .eh_frame sections when linking.
> >
> > Originally, the compiler would implicitly add --eh-frame-hdr when
> > invoking the linker, but when this Makefile was converted from invoking
> > ld via the compiler, to invoking it directly (like vmlinux does),
> > the flag was missed. (The EH_FRAME section is important for the VDSO
> > shared libraries, but not for vmlinux.)
> >
> > Fix the problem by explicitly specifying --eh-frame-hdr, which restores
> > parity with the old method.
> >
> > See relevant bug reports for additional info:
> >
> > https://bugzilla.kernel.org/show_bug.cgi?id=201741
> > https://bugzilla.redhat.com/show_bug.cgi?id=1659295
> >
> > Fixes: 379d98ddf413 ("x86: vdso: Use $LD instead of $CC to link")
> > Reported-by: Florian Weimer <fweimer@xxxxxxxxxx>
> > Reported-by: Carlos O'Donell <carlos@xxxxxxxxxx>
> > Reported-by: "H. J. Lu" <hjl.tools@xxxxxxxxx>
> > Signed-off-by: Alistair Strachan <astrachan@xxxxxxxxxx>
> > Signed-off-by: Borislav Petkov <bp@xxxxxxx>
> > Tested-by: Laura Abbott <labbott@xxxxxxxxxx>
> > Cc: Andy Lutomirski <luto@xxxxxxxxxx>
> > Cc: Carlos O'Donell <carlos@xxxxxxxxxx>
> > Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> > Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> > Cc: Joel Fernandes <joel@xxxxxxxxxxxxxxxxx>
> > Cc: kernel-team@xxxxxxxxxxx
> > Cc: Laura Abbott <labbott@xxxxxxxxxx>
> > Cc: stable <stable@xxxxxxxxxxxxxxx>
> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > Cc: X86 ML <x86@xxxxxxxxxx>
> > Link: https://lkml.kernel.org/r/20181214223637.35954-1-astrachan@xxxxxxxxxx
> > Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@xxxxxxxxxxxxx>
> > ---
> > arch/x86/entry/vdso/Makefile | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
>
> This is already in the 4.14 stable queue.
>
> Sasha, how did you tools miss it for 4.4 and 4.9?
Not Sasha's fault but mine, I forgot to git grep for the short hash like
I usually do to ensure I catch all fixes (or I didn't do it properly, I
forget which) when I added this to all of the trees.
I currently see it queued up for 4.9 and 4.14, don't forget 4.4.
Sorry for the breakage,
Nathan
>
> thanks,
>
> greg k-h
