From 14a3f40aafacde1dfd6912327ae14df4baf10304 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Fri, 23 Oct 2009 07:31:01 -0700 Subject: x86: Remove STACKPROTECTOR_ALL STACKPROTECTOR_ALL has a really high overhead (runtime and stack footprint) and is not really worth it protection wise (the normal STACKPROTECTOR is in effect for all functions with buffers already), so lets just remove the option entirely. Reported-by: Dave Jones Reported-by: Chuck Ebbert Signed-off-by: Arjan van de Ven Cc: Eric Sandeen LKML-Reference: <20091023073101.3dce4ebb@infradead.org> Signed-off-by: Ingo Molnar --- arch/x86/Kconfig | 4 ---- arch/x86/Makefile | 1 - 2 files changed, 5 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 07e01149e3bf..72ace9515a07 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1443,12 +1443,8 @@ config SECCOMP If unsure, say Y. Only embedded should say N here. -config CC_STACKPROTECTOR_ALL - bool - config CC_STACKPROTECTOR bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)" - select CC_STACKPROTECTOR_ALL ---help--- This option turns on the -fstack-protector GCC feature. This feature puts, at the beginning of functions, a canary value on diff --git a/arch/x86/Makefile b/arch/x86/Makefile index a012ee8ef803..d2d24c9ee64d 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -76,7 +76,6 @@ ifdef CONFIG_CC_STACKPROTECTOR cc_has_sp := $(srctree)/scripts/gcc-x86_$(BITS)-has-stack-protector.sh ifeq ($(shell $(CONFIG_SHELL) $(cc_has_sp) $(CC) $(biarch)),y) stackp-y := -fstack-protector - stackp-$(CONFIG_CC_STACKPROTECTOR_ALL) += -fstack-protector-all KBUILD_CFLAGS += $(stackp-y) else $(warning stack protector enabled but no compiler support) -- cgit v1.2.3 From ae1b22f6e46c03cede7cea234d0bf2253b4261cf Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 26 Oct 2009 14:26:04 +1030 Subject: x86: Side-step lguest problem by only building cmpxchg8b_emu for pre-Pentium Commit 79e1dd05d1a22 "x86: Provide an alternative() based cmpxchg64()" broke lguest, even on systems which have cmpxchg8b support. The emulation code gets used until alternatives get run, but it contains native instructions, not their paravirt alternatives. The simplest fix is to turn this code off except for 386 and 486 builds. Reported-by: Johannes Stezenbach Signed-off-by: Rusty Russell Acked-by: H. Peter Anvin Cc: lguest@ozlabs.org Cc: Arjan van de Ven Cc: Jeremy Fitzhardinge Cc: Linus Torvalds LKML-Reference: <200910261426.05769.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar --- arch/x86/Kconfig.cpu | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu index f2824fb8c79c..2649840d888f 100644 --- a/arch/x86/Kconfig.cpu +++ b/arch/x86/Kconfig.cpu @@ -400,7 +400,7 @@ config X86_TSC config X86_CMPXCHG64 def_bool y - depends on X86_PAE || X86_64 || MCORE2 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MATOM + depends on !M386 && !M486 # this should be set for all -march=.. options where the compiler # generates cmov. -- cgit v1.2.3 From 72ed7de74e8f0fad0d8e567ae1f987b740accb3f Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 26 Oct 2009 11:11:43 +0100 Subject: x86: crash_dump: Fix non-pae kdump kernel memory accesses Non-PAE 32-bit dump kernels may wrap an address around 4G and poke unwanted space. ptes there are 32-bit long, and since pfn << PAGE_SIZE may exceed this limit, high pfn bits are cropped and wrong address mapped by kmap_atomic_pfn in copy_oldmem_page. Don't allow this behavior in non-PAE kdump kernels by checking pfns passed into copy_oldmem_page. In the case of failure, userspace process gets EFAULT. [v2] - fix comments - move ifdefs inside the function Signed-off-by: Jiri Slaby Cc: Vivek Goyal Cc: Eric W. Biederman Cc: Simon Horman Cc: Paul Mundt LKML-Reference: <1256551903-30567-1-git-send-email-jirislaby@gmail.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/crash_dump_32.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/arch/x86/kernel/crash_dump_32.c b/arch/x86/kernel/crash_dump_32.c index f7cdb3b457aa..cd97ce18c29d 100644 --- a/arch/x86/kernel/crash_dump_32.c +++ b/arch/x86/kernel/crash_dump_32.c @@ -16,6 +16,22 @@ static void *kdump_buf_page; /* Stores the physical address of elf header of crash image. */ unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX; +static inline bool is_crashed_pfn_valid(unsigned long pfn) +{ +#ifndef CONFIG_X86_PAE + /* + * non-PAE kdump kernel executed from a PAE one will crop high pte + * bits and poke unwanted space counting again from address 0, we + * don't want that. pte must fit into unsigned long. In fact the + * test checks high 12 bits for being zero (pfn will be shifted left + * by PAGE_SHIFT). + */ + return pte_pfn(pfn_pte(pfn, __pgprot(0))) == pfn; +#else + return true; +#endif +} + /** * copy_oldmem_page - copy one page from "oldmem" * @pfn: page frame number to be copied @@ -41,6 +57,9 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, if (!csize) return 0; + if (!is_crashed_pfn_valid(pfn)) + return -EFAULT; + vaddr = kmap_atomic_pfn(pfn, KM_PTE0); if (!userbuf) { -- cgit v1.2.3 From 81766741fe1eee3884219e8daaf03f466f2ed52f Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 26 Oct 2009 15:20:29 +0000 Subject: x86-64: Fix register leak in 32-bit syscall audting Restoring %ebp after the call to audit_syscall_exit() is not only unnecessary (because the register didn't get clobbered), but in the sysenter case wasn't even doing the right thing: It loaded %ebp from a location below the top of stack (RBP < ARGOFFSET), i.e. arbitrary kernel data got passed back to user mode in the register. Signed-off-by: Jan Beulich Acked-by: Roland McGrath Cc: LKML-Reference: <4AE5CC4D020000780001BD13@vpn.id2.novell.com> Signed-off-by: Ingo Molnar --- arch/x86/ia32/ia32entry.S | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index 1733f9f65e82..581b0568fe19 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -204,7 +204,7 @@ sysexit_from_sys_call: movl RDI-ARGOFFSET(%rsp),%r8d /* reload 5th syscall arg */ .endm - .macro auditsys_exit exit,ebpsave=RBP + .macro auditsys_exit exit testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),TI_flags(%r10) jnz ia32_ret_from_sys_call TRACE_IRQS_ON @@ -217,7 +217,6 @@ sysexit_from_sys_call: call audit_syscall_exit GET_THREAD_INFO(%r10) movl RAX-ARGOFFSET(%rsp),%eax /* reload syscall return value */ - movl \ebpsave-ARGOFFSET(%rsp),%ebp /* reload user register value */ movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi cli TRACE_IRQS_OFF @@ -351,7 +350,7 @@ cstar_auditsys: jmp cstar_dispatch sysretl_audit: - auditsys_exit sysretl_from_sys_call, RCX /* user %ebp in RCX slot */ + auditsys_exit sysretl_from_sys_call #endif cstar_tracesys: -- cgit v1.2.3 From 772be899bc022ef2b911c3611b487d417e3269c3 Mon Sep 17 00:00:00 2001 From: Feng Tang Date: Tue, 20 Oct 2009 12:54:02 +0800 Subject: x86: Make EFI RTC function depend on 32bit again The EFI RTC functions are only available on 32 bit. commit 7bd867df (x86: Move get/set_wallclock to x86_platform_ops) removed the 32bit dependency which leads to boot crashes on 64bit EFI systems. Add the dependency back. Solves: http://bugzilla.kernel.org/show_bug.cgi?id=14466 Tested-by: Matthew Garrett Signed-off-by: Feng Tang LKML-Reference: <20091020125402.028d66d5@feng-desktop> Signed-off-by: Thomas Gleixner --- arch/x86/kernel/efi.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kernel/efi.c b/arch/x86/kernel/efi.c index ad5bd988fb79..cdcfb122f256 100644 --- a/arch/x86/kernel/efi.c +++ b/arch/x86/kernel/efi.c @@ -454,8 +454,10 @@ void __init efi_init(void) if (add_efi_memmap) do_add_efi_memmap(); +#ifdef CONFIG_X86_32 x86_platform.get_wallclock = efi_get_time; x86_platform.set_wallclock = efi_set_rtc_mmss; +#endif /* Setup for EFI runtime service */ reboot_type = BOOT_EFI; -- cgit v1.2.3