From a7916a1de526162d73e894b6d3ebd895d4302078 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Thu, 31 Jan 2019 10:09:00 +0000 Subject: powerpc: regain entire stack space thread_info is not anymore in the stack, so the entire stack can now be used. There is also no risk anymore of corrupting task_cpu(p) with a stack overflow so the patch removes the test. When doing this, an explicit test for NULL stack pointer is needed in validate_sp() as it is not anymore implicitely covered by the sizeof(thread_info) gap. In the meantime, with the previous patch all pointers to the stacks are not anymore pointers to thread_info so this patch changes them to void* Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/entry_32.S | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) (limited to 'arch/powerpc/kernel/entry_32.S') diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index f3618353c1c4..424e7265e790 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -97,14 +97,11 @@ crit_transfer_to_handler: mfspr r0,SPRN_SRR1 stw r0,_SRR1(r11) - /* set the stack limit to the current stack - * and set the limit to protect the thread_info - * struct - */ + /* set the stack limit to the current stack */ mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,SAVED_KSP_LIMIT(r11) - rlwimi r0,r1,0,0,(31-THREAD_SHIFT) + rlwinm r0,r1,0,0,(31 - THREAD_SHIFT) stw r0,KSP_LIMIT(r8) /* fall through */ #endif @@ -121,14 +118,11 @@ crit_transfer_to_handler: mfspr r0,SPRN_SRR1 stw r0,crit_srr1@l(0) - /* set the stack limit to the current stack - * and set the limit to protect the thread_info - * struct - */ + /* set the stack limit to the current stack */ mfspr r8,SPRN_SPRG_THREAD lwz r0,KSP_LIMIT(r8) stw r0,saved_ksp_limit@l(0) - rlwimi r0,r1,0,0,(31-THREAD_SHIFT) + rlwinm r0,r1,0,0,(31 - THREAD_SHIFT) stw r0,KSP_LIMIT(r8) /* fall through */ #endif -- cgit v1.2.3