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authorScott Wood <oss@buserror.net>2017-05-05 01:22:06 -0500
committerScott Wood <oss@buserror.net>2017-05-05 01:22:06 -0500
commit61baf15555129f69720334f232b153890895ef71 (patch)
tree1f6dc2dd8642537cedaca84d22a42ed87befd9ab /arch
parent726bd223105c04f7bf5eacdc2540819c301061f7 (diff)
downloadop-kernel-dev-61baf15555129f69720334f232b153890895ef71.zip
op-kernel-dev-61baf15555129f69720334f232b153890895ef71.tar.gz
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 <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Scott Wood <oss@buserror.net>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/include/asm/processor.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index a4b1d8d..a2123f2 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() ? \
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