From d751c169e9a6f0f853346f1184881422bd10b3c2 Mon Sep 17 00:00:00 2001 From: Michael Davidson Date: Thu, 10 Oct 2013 18:39:54 -0700 Subject: x86, relocs: Add more per-cpu gold special cases The "gold" linker doesn't seem to put some additional per-cpu cases in the right place. Add these to the per-cpu check. Without this, the kASLR patch series fails to correctly apply relocations, and fails to boot. Signed-off-by: Michael Davidson Signed-off-by: Kees Cook Link: http://lkml.kernel.org/r/20131011013954.GA28902@www.outflux.net Signed-off-by: H. Peter Anvin --- arch/x86/tools/relocs.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'arch/x86/tools') diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c index f7bab68a4b83..71a2533c90d3 100644 --- a/arch/x86/tools/relocs.c +++ b/arch/x86/tools/relocs.c @@ -722,15 +722,23 @@ static void percpu_init(void) /* * Check to see if a symbol lies in the .data..percpu section. - * For some as yet not understood reason the "__init_begin" - * symbol which immediately preceeds the .data..percpu section - * also shows up as it it were part of it so we do an explict - * check for that symbol name and ignore it. + * + * The linker incorrectly associates some symbols with the + * .data..percpu section so we also need to check the symbol + * name to make sure that we classify the symbol correctly. + * + * The GNU linker incorrectly associates: + * __init_begin + * + * The "gold" linker incorrectly associates: + * init_per_cpu__irq_stack_union + * init_per_cpu__gdt_page */ static int is_percpu_sym(ElfW(Sym) *sym, const char *symname) { return (sym->st_shndx == per_cpu_shndx) && - strcmp(symname, "__init_begin"); + strcmp(symname, "__init_begin") && + strncmp(symname, "init_per_cpu_", 13); } -- cgit v1.2.1 From aec58bafaf89279522c44ec8ca9211eabb2b6976 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 15 Oct 2013 23:43:14 -0700 Subject: x86/relocs: Add percpu fixup for GNU ld 2.23 The GNU linker tries to put __per_cpu_load into the percpu area, resulting in a lack of its relocation. Force this symbol to be relocated. Seen starting with GNU ld 2.23 and later. Reported-by: Ingo Molnar Signed-off-by: Kees Cook Cc: Michael Davidson Cc: Cong Ding Link: http://lkml.kernel.org/r/20131016064314.GA2739@www.outflux.net Signed-off-by: Ingo Molnar --- arch/x86/tools/relocs.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/tools') diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c index 71a2533c90d3..11f9285a2ff6 100644 --- a/arch/x86/tools/relocs.c +++ b/arch/x86/tools/relocs.c @@ -729,6 +729,7 @@ static void percpu_init(void) * * The GNU linker incorrectly associates: * __init_begin + * __per_cpu_load * * The "gold" linker incorrectly associates: * init_per_cpu__irq_stack_union @@ -738,6 +739,7 @@ static int is_percpu_sym(ElfW(Sym) *sym, const char *symname) { return (sym->st_shndx == per_cpu_shndx) && strcmp(symname, "__init_begin") && + strcmp(symname, "__per_cpu_load") && strncmp(symname, "init_per_cpu_", 13); } -- cgit v1.2.1