From: Scott Wood Date: Fri, 5 May 2017 06:22:06 +0000 (-0500) Subject: powerpc/64e: Don't place the stack beyond TASK_SIZE X-Git-Tag: v4.12-rc1~17^2~3^2 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=61baf15555129f69720334f232b153890895ef71;p=karo-tx-linux.git powerpc/64e: Don't place the stack beyond TASK_SIZE Commit f4ea6dcb08ea ("powerpc/mm: Enable mappings above 128TB") increased the task size on book3s, and introduced a mechanism to dynamically control whether a task uses these larger addresses. While the change to the task size itself was ifdef-protected to only apply on book3s, the change to STACK_TOP_USER64 was not. On book3e, this had the effect of trying to use addresses up to 128TiB for the stack despite a 64TiB task size limit -- which broke 64-bit userspace producing the following errors: Starting init: /sbin/init exists but couldn't execute it (error -14) Starting init: /bin/sh exists but couldn't execute it (error -14) Kernel panic - not syncing: No working init found. Try passing init= option to kernel. See Linux Documentation/admin-guide/init.rst for guidance. Fixes: f4ea6dcb08ea ("powerpc/mm: Enable mappings above 128TB") Cc: Aneesh Kumar K.V Signed-off-by: Scott Wood --- diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index a4b1d8d6b793..a2123f291ab0 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -151,8 +151,13 @@ void release_thread(struct task_struct *); #ifdef __powerpc64__ +#ifdef CONFIG_PPC_BOOK3S_64 /* Limit stack to 128TB */ #define STACK_TOP_USER64 TASK_SIZE_128TB +#else +#define STACK_TOP_USER64 TASK_SIZE_USER64 +#endif + #define STACK_TOP_USER32 TASK_SIZE_USER32 #define STACK_TOP (is_32bit_task() ? \