user/sven/linux.git/arch/x86/include/asm/stackprotector.h, branch v3.2.70

x86/i386: Make sure stack-protector segment base is cache aligned

2009-09-03T19:30:51Z

The Intel Optimization Reference Guide says: In Intel Atom microarchitecture, the address generation unit assumes that the segment base will be 0 by default. Non-zero segment base will cause load and store operations to experience a delay. - If the segment base isn't aligned to a cache line boundary, the max throughput of memory operations is reduced to one [e]very 9 cycles. [...] Assembly/Compiler Coding Rule 15. (H impact, ML generality) For Intel Atom processors, use segments with base set to 0 whenever possible; avoid non-zero segment base address that is not aligned to cache line boundary at all cost. We can't avoid having a non-zero base for the stack-protector segment, but we can make it cache-aligned. Signed-off-by: Jeremy Fitzhardinge Cc: LKML-Reference: <4AA01893.6000507@goop.org> Signed-off-by: Ingo Molnar

x86: Introduce GDT_ENTRY_INIT()

2009-08-08T15:44:11Z

GDT_ENTRY_INIT is static initializer of desc_struct. We already have similar macro GDT_ENTRY() but it's static initializer for u64 and it cannot be used for desc_struct. Signed-off-by: Akinobu Mita LKML-Reference: <20090718151219.GD11294@localhost.localdomain> Signed-off-by: Ingo Molnar

x86: Introduce set_desc_base() and set_desc_limit()

2009-07-19T16:27:52Z

Rename set_base()/set_limit to set_desc_base()/set_desc_limit() and rewrite them in C. These are naturally introduced by the idea of get_desc_base()/get_desc_limit(). The conversion actually found the bug in apm_32.c: bad_bios_desc is written at run-time, but it is defined const variable. Signed-off-by: Akinobu Mita LKML-Reference: <20090718151105.GC11294@localhost.localdomain> Signed-off-by: Ingo Molnar

x86: fix x86_32 stack protector bugs

2009-02-11T10:33:49Z

Impact: fix x86_32 stack protector Brian Gerst found out that %gs was being initialized to stack_canary instead of stack_canary - 20, which basically gave the same canary value for all threads. Fixing this also exposed the following bugs. * cpu_idle() didn't call boot_init_stack_canary() * stack canary switching in switch_to() was being done too late making the initial run of a new thread use the old stack canary value. Fix all of them and while at it update comment in cpu_idle() about calling boot_init_stack_canary(). Reported-by: Brian Gerst Signed-off-by: Tejun Heo Signed-off-by: Ingo Molnar

x86: implement x86_32 stack protector

2009-02-09T23:42:01Z

Impact: stack protector for x86_32 Implement stack protector for x86_32. GDT entry 28 is used for it. It's set to point to stack_canary-20 and have the length of 24 bytes. CONFIG_CC_STACKPROTECTOR turns off CONFIG_X86_32_LAZY_GS and sets %gs to the stack canary segment on entry. As %gs is otherwise unused by the kernel, the canary can be anywhere. It's defined as a percpu variable. x86_32 exception handlers take register frame on stack directly as struct pt_regs. With -fstack-protector turned on, gcc copies the whole structure after the stack canary and (of course) doesn't copy back on return thus losing all changed. For now, -fno-stack-protector is added to all files which contain those functions. We definitely need something better. Signed-off-by: Tejun Heo Signed-off-by: Ingo Molnar

x86: stackprotector.h misc update

2009-02-09T23:41:29Z

Impact: misc udpate * wrap content with CONFIG_CC_STACK_PROTECTOR so that other arch files can include it directly * add missing includes This will help future changes. Signed-off-by: Tejun Heo Signed-off-by: Ingo Molnar

x86: move stack_canary into irq_stack

2009-01-20T03:29:20Z

Impact: x86_64 percpu area layout change, irq_stack now at the beginning Now that the PDA is empty except for the stack canary, it can be removed. The irqstack is moved to the start of the per-cpu section. If the stack protector is enabled, the canary overlaps the bottom 48 bytes of the irqstack. tj: * updated subject * dropped asm relocation of irq_stack_ptr * updated comments a bit * rebased on top of stack canary changes Signed-off-by: Brian Gerst Signed-off-by: Tejun Heo

x86: cleanup stack protector

2009-01-20T03:29:19Z

Impact: cleanup Make the following cleanups. * remove duplicate comment from boot_init_stack_canary() which fits better in the other place - cpu_idle(). * move stack_canary offset check from __switch_to() to boot_init_stack_canary(). Signed-off-by: Tejun Heo

Merge branch 'core/percpu' into stackprotector

2009-01-18T17:37:14Z

Conflicts: arch/x86/include/asm/pda.h arch/x86/include/asm/system.h Also, moved include/asm-x86/stackprotector.h to arch/x86/include/asm. Signed-off-by: Ingo Molnar