From 9f88b906b4455465d60ac18b8c95904f320038d5 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Thu, 3 Jul 2014 15:34:38 +0100 Subject: x86-64, vdso: Fix vDSO build breakage due to empty .rela.dyn Certain ld versions (observed with 2.20.0) put an empty .rela.dyn section into shared object files, breaking the assumption on the number of sections to be copied to the final output. Simply discard any empty SHT_REL and SHT_RELA sections to address this. Signed-off-by: Jan Beulich Link: http://lkml.kernel.org/r/53B5861E02000078000204D1@mail.emea.novell.com Acked-by: Andy Lutomirski Tested-by: Boris Ostrovsky Tested-by: Andrew Morton Signed-off-by: H. Peter Anvin --- arch/x86/vdso/vdso2c.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch') diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h index df95a2fdff73..11b65d4f9414 100644 --- a/arch/x86/vdso/vdso2c.h +++ b/arch/x86/vdso/vdso2c.h @@ -93,6 +93,9 @@ static void BITSFUNC(copy_section)(struct BITSFUNC(fake_sections) *out, uint64_t flags = GET_LE(&in->sh_flags); bool copy = flags & SHF_ALLOC && + (GET_LE(&in->sh_size) || + (GET_LE(&in->sh_type) != SHT_RELA && + GET_LE(&in->sh_type) != SHT_REL)) && strcmp(name, ".altinstructions") && strcmp(name, ".altinstr_replacement"); -- cgit v1.2.3-59-g8ed1b From d093601be5e97d2729614419d0d256ed3b6a56b0 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Thu, 3 Jul 2014 15:35:07 +0100 Subject: x86-32, vdso: Fix vDSO build error due to missing align_vdso_addr() Relying on static functions used just once to get inlined (and subsequently have dead code paths eliminated) is wrong: Compilers are free to decide whether they do this, regardless of optimization level. With this not happening for vdso_addr() (observed with gcc 4.1.x), an unresolved reference to align_vdso_addr() causes the build to fail. [ hpa: vdso_addr() is never actually used on x86-32, as calculate_addr in map_vdso() is always false. It ought to be possible to clean this up further, but this fixes the immediate problem. ] Signed-off-by: Jan Beulich Link: http://lkml.kernel.org/r/53B5863B02000078000204D5@mail.emea.novell.com Acked-by: Andy Lutomirski Tested-by: Boris Ostrovsky Tested-by: Andrew Morton Signed-off-by: H. Peter Anvin --- arch/x86/vdso/vma.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch') diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c index e1513c47872a..5a5176de8d0a 100644 --- a/arch/x86/vdso/vma.c +++ b/arch/x86/vdso/vma.c @@ -62,6 +62,9 @@ struct linux_binprm; Only used for the 64-bit and x32 vdsos. */ static unsigned long vdso_addr(unsigned long start, unsigned len) { +#ifdef CONFIG_X86_32 + return 0; +#else unsigned long addr, end; unsigned offset; end = (start + PMD_SIZE - 1) & PMD_MASK; @@ -83,6 +86,7 @@ static unsigned long vdso_addr(unsigned long start, unsigned len) addr = align_vdso_addr(addr); return addr; +#endif } static int map_vdso(const struct vdso_image *image, bool calculate_addr) -- cgit v1.2.3-59-g8ed1b