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author | Thomas Gleixner <tglx@linutronix.de> | 2013-06-10 16:52:03 +0200 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2013-06-11 22:04:47 +0200 |
commit | d7880812b3594d3c6dcbe3cfd71dabb17347d082 (patch) | |
tree | 87d72f75a691ac0d23776afcde0e9f35c09d8148 /kernel | |
parent | Linux 3.10-rc2 (diff) | |
download | linux-d7880812b3594d3c6dcbe3cfd71dabb17347d082.tar.xz linux-d7880812b3594d3c6dcbe3cfd71dabb17347d082.zip |
idle: Add the stack canary init to cpu_startup_entry()
Moving x86 to the generic idle implementation (commit 7d1a9417 "x86:
Use generic idle loop") wreckaged the stack protector.
I stupidly missed that boot_init_stack_canary() must be inlined from a
function which never returns, but I put that call into
arch_cpu_idle_prepare() which of course returns.
I pondered to play tricks with arch_cpu_idle_prepare() first, but then
I noticed, that the other archs which have implemented the
stackprotector (ARM and SH) do not initialize the canary for the
non-boot cpus.
So I decided to move the boot_init_stack_canary() call into
cpu_startup_entry() ifdeffed with an CONFIG_X86 for now. This #ifdef
is just a temporary measure as I don't want to inflict the
boot_init_stack_canary() call on ARM and SH that late in the cycle.
I'll queue a patch for 3.11 which removes the #ifdef if the ARM/SH
maintainers have no objection.
Reported-by: Wouter van Kesteren <woutershep@gmail.com>
Cc: x86@kernel.org
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/cpu/idle.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/kernel/cpu/idle.c b/kernel/cpu/idle.c index d5585f5e038e..bf2ee1aafa0e 100644 --- a/kernel/cpu/idle.c +++ b/kernel/cpu/idle.c @@ -5,6 +5,7 @@ #include <linux/cpu.h> #include <linux/tick.h> #include <linux/mm.h> +#include <linux/stackprotector.h> #include <asm/tlb.h> @@ -112,6 +113,21 @@ static void cpu_idle_loop(void) void cpu_startup_entry(enum cpuhp_state state) { + /* + * This #ifdef needs to die, but it's too late in the cycle to + * make this generic (arm and sh have never invoked the canary + * init for the non boot cpus!). Will be fixed in 3.11 + */ +#ifdef CONFIG_X86 + /* + * If we're the non-boot CPU, nothing set the stack canary up + * for us. The boot CPU already has it initialized but no harm + * in doing it again. This is a good place for updating it, as + * we wont ever return from this function (so the invalid + * canaries already on the stack wont ever trigger). + */ + boot_init_stack_canary(); +#endif current_set_polling(); arch_cpu_idle_prepare(); cpu_idle_loop(); |