From 46176b4f6bac19454b7b5c35f68594b85850a600 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 26 May 2009 14:42:40 +0900 Subject: x86, relocs: ignore R_386_NONE in kernel relocation entries For relocatable 32bit kernels, boot/compressed/relocs.c processes relocation entries in the kernel image and appends it to the kernel image such that boot/compressed/head_32.S can relocate the kernel. The kernel image is one statically linked object and only uses two relocation types - R_386_PC32 and R_386_32, of the two only the latter needs massaging during kernel relocation and thus handled by relocs. R_386_PC32 is ignored and all other relocation types are considered error. When the target of a relocation resides in a discarded section, binutils doesn't throw away the relocation record but nullifies it by changing it to R_386_NONE, which unfortunately makes relocs fail. The problem was triggered by yet out-of-tree x86 stack unwind patches but given the binutils behavior, ignoring R_386_NONE is the right thing to do. The problem has been tracked down to binutils behavior by Jan Beulich. [ Impact: fix build with certain binutils by ignoring R_386_NONE ] Signed-off-by: Tejun Heo Cc: Jan Beulich Cc: Ingo Molnar LKML-Reference: <4A1B8150.40702@kernel.org> Signed-off-by: H. Peter Anvin --- arch/x86/boot/compressed/relocs.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/x86/boot/compressed/relocs.c b/arch/x86/boot/compressed/relocs.c index 857e492c571e..bbeb0c3fbd90 100644 --- a/arch/x86/boot/compressed/relocs.c +++ b/arch/x86/boot/compressed/relocs.c @@ -504,8 +504,11 @@ static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym)) if (sym->st_shndx == SHN_ABS) { continue; } - if (r_type == R_386_PC32) { - /* PC relative relocations don't need to be adjusted */ + if (r_type == R_386_NONE || r_type == R_386_PC32) { + /* + * NONE can be ignored and and PC relative + * relocations don't need to be adjusted. + */ } else if (r_type == R_386_32) { /* Visit relocations that need to be adjusted */ -- cgit v1.2.3 From 2171787be2e71ff71159857bfeb21398b61eb615 Mon Sep 17 00:00:00 2001 From: Pallipadi, Venkatesh Date: Tue, 26 May 2009 10:33:35 -0700 Subject: x86: avoid back to back on_each_cpu in cpa_flush_array Cleanup cpa_flush_array() to avoid back to back on_each_cpu() calls. [ Impact: optimizes fix 0af48f42df15b97080b450d24219dd95db7b929a ] Signed-off-by: Venkatesh Pallipadi Signed-off-by: H. Peter Anvin --- arch/x86/mm/pageattr.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) (limited to 'arch') diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 0f9052bcec4b..e17efed088c5 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -204,30 +204,19 @@ static void cpa_flush_range(unsigned long start, int numpages, int cache) } } -static void wbinvd_local(void *unused) -{ - wbinvd(); -} - static void cpa_flush_array(unsigned long *start, int numpages, int cache, int in_flags, struct page **pages) { unsigned int i, level; + unsigned long do_wbinvd = cache && numpages >= 1024; /* 4M threshold */ BUG_ON(irqs_disabled()); - on_each_cpu(__cpa_flush_range, NULL, 1); + on_each_cpu(__cpa_flush_all, (void *) do_wbinvd, 1); - if (!cache) + if (!cache || do_wbinvd) return; - /* 4M threshold */ - if (numpages >= 1024) { - if (boot_cpu_data.x86 >= 4) - on_each_cpu(wbinvd_local, NULL, 1); - - return; - } /* * We only need to flush on one CPU, * clflush is a MESI-coherent instruction that -- cgit v1.2.3