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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2018-10-13 09:45:12 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-10-13 22:21:25 +1100 |
| commit | 7241d26e8175e95290a6549a470c330dbfc63442 (patch) | |
| tree | b1e0873d7940340c6054873611e08a91ab2db016 /arch/powerpc/kernel/smp.c | |
| parent | 9b7e4d601baac83a7104652042107ce94f245524 (diff) | |
| download | linux-7241d26e8175e95290a6549a470c330dbfc63442.tar.gz | |
powerpc/64: properly initialise the stackprotector canary on SMP.
commit 06ec27aea9fc ("powerpc/64: add stack protector support")
doesn't initialise the stack canary on SMP secondary CPU's paca,
leading to the following false positive report from the
stack protector.
smp: Bringing up secondary CPUs ...
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: __schedule+0x978/0xa80
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.0-rc7-next-20181010-autotest-autotest #1
Call Trace:
[c000001fed5b3bf0] [c000000000a0ef3c] dump_stack+0xb0/0xf4 (unreliable)
[c000001fed5b3c30] [c0000000000f9d68] panic+0x140/0x308
[c000001fed5b3cc0] [c0000000000f9844] __stack_chk_fail+0x24/0x30
[c000001fed5b3d20] [c000000000a2c3a8] __schedule+0x978/0xa80
[c000001fed5b3e00] [c000000000a2c9b4] schedule_idle+0x34/0x60
[c000001fed5b3e30] [c00000000013d344] do_idle+0x224/0x3d0
[c000001fed5b3ec0] [c00000000013d6e0] cpu_startup_entry+0x30/0x50
[c000001fed5b3ef0] [c000000000047f34] start_secondary+0x4d4/0x520
[c000001fed5b3f90] [c00000000000b370] start_secondary_prolog+0x10/0x14
This patch properly initialises the stack_canary of the secondary
idle tasks.
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Fixes: 06ec27aea9fc ("powerpc/64: add stack protector support")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/smp.c')
| -rw-r--r-- | arch/powerpc/kernel/smp.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 61c1fadbc64444..e774d3bf3a03b4 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -34,6 +34,7 @@ #include <linux/topology.h> #include <linux/profile.h> #include <linux/processor.h> +#include <linux/random.h> #include <asm/ptrace.h> #include <linux/atomic.h> @@ -810,9 +811,16 @@ static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle) { struct thread_info *ti = task_thread_info(idle); +#ifdef CONFIG_STACKPROTECTOR + idle->stack_canary = get_random_canary(); +#endif + #ifdef CONFIG_PPC64 paca_ptrs[cpu]->__current = idle; paca_ptrs[cpu]->kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD; +#ifdef CONFIG_STACKPROTECTOR + paca_ptrs[cpu]->canary = idle->stack_canary; +#endif #endif ti->cpu = cpu; secondary_ti = current_set[cpu] = ti; |