Re: 2.6.29.1 sparc64 boot failure

[David Miller <davem@davemloft.net>]

From: Zoltan Kovacs <giszo.k@gmail.com>
Date: Wed, 8 Apr 2009 12:38:19 +0200

> Hi,
> 
> I just tried to put the latest kernel (2.6.29.1) to my Sun Fire V250
> sparc server machine.
> 
> When I booted the system with the new kernel it just failed with the
> following error message:
> "kernel BUG at /usr/src/linux-2.6.29.1/arch/sparc/include/asm/tlb_64.h:48!"
> 
> The full boot log and kernel config is attached to the mail.

Known problem, patch already posted and submitted to -stable:

sparc64: Fix bug in ("sparc64: Flush TLB before releasing pages.")

[ No upstream commit, this regression was added only to 2.6.29.1 ]

Unfortunately I merged an earlier version of commit
b6816b706138c3870f03115071872cad824f90b4 ("sparc64: Flush TLB before
releasing pages.") than what I actually tested and merged upstream.

Simply diffing asm/tlb_64.h in Linus's tree vs. what ended up in
2.6.29.1 confirms this.

Sync things up to fix BUG() triggers some users are seeing.

Reported-by: Dennis Gilmore <dennis@ausil.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 arch/sparc/include/asm/tlb_64.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/sparc/include/asm/tlb_64.h b/arch/sparc/include/asm/tlb_64.h
index 0aaa086..ee38e73 100644
--- a/arch/sparc/include/asm/tlb_64.h
+++ b/arch/sparc/include/asm/tlb_64.h
@@ -57,9 +57,9 @@ static inline struct mmu_gather *tlb_gather_mmu(struct mm_struct *mm, unsigned i
 
 static inline void tlb_flush_mmu(struct mmu_gather *mp)
 {
+	if (!mp->fullmm)
+		flush_tlb_pending();
 	if (mp->need_flush) {
-		if (!mp->fullmm)
-			flush_tlb_pending();
 		free_pages_and_swap_cache(mp->pages, mp->pages_nr);
 		mp->pages_nr = 0;
 		mp->need_flush = 0;
-- 
1.6.2.2