From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Hromatka Date: Fri, 31 Mar 2017 22:31:42 +0000 Subject: [PATCH] sparc64: Fix kernel panic due to erroneous #ifdef surrounding pmd_write() Message-Id: <1490999502-88236-1-git-send-email-tom.hromatka@oracle.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: sparclinux@vger.kernel.org This commit moves sparc64's prototype of pmd_write() outside of the CONFIG_TRANSPARENT_HUGEPAGE ifdef. In 2013, commit a7b9403f0e6d ("sparc64: Encode huge PMDs using PTE encoding.") exposed a path where pmd_write() could be called without CONFIG_TRANSPARENT_HUGEPAGE defined. This can result in the panic below. The diff is awkward to read, but the changes are straightforward. pmd_write() was moved outside of #ifdef CONFIG_TRANSPARENT_HUGEPAGE. Also, __HAVE_ARCH_PMD_WRITE was defined. kernel BUG at include/asm-generic/pgtable.h:576! \|/ ____ \|/ "@'/ .. \`@" /_| \__/ |_\ \__U_/ oracle_8114_cdb(8114): Kernel bad sw trap 5 [#1] CPU: 120 PID: 8114 Comm: oracle_8114_cdb Not tainted 4.1.12-61.7.1.el6uek.rc1.sparc64 #1 task: fff8400700a24d60 ti: fff8400700bc4000 task.ti: fff8400700bc4000 TSTATE: 0000004411e01607 TPC: 00000000004609f8 TNPC: 00000000004609fc Y: 00000005 Not tainted TPC: g0: 000000000001c000 g1: 0000000000ef3954 g2: 0000000000000000 g3: 0000000000000001 g4: fff8400700a24d60 g5: fff8001fa5c10000 g6: fff8400700bc4000 g7: 0000000000000720 o0: 0000000000bc5058 o1: 0000000000000240 o2: 0000000000006000 o3: 0000000000001c00 o4: 0000000000000000 o5: 0000048000080000 sp: fff8400700bc6ab1 ret_pc: 00000000004609f0 RPC: l0: fff8400700bc74fc l1: 0000000000020000 l2: 0000000000002000 l3: 0000000000000000 l4: fff8001f93250950 l5: 000000000113f800 l6: 0000000000000004 l7: 0000000000000000 i0: fff8400700ca46a0 i1: bd0000085e800453 i2: 000000026a0c4000 i3: 000000026a0c6000 i4: 0000000000000001 i5: fff800070c958de8 i6: fff8400700bc6b61 i7: 0000000000460dd0 I7: Call Trace: [0000000000460dd0] gup_pud_range+0x170/0x1a0 [0000000000460e84] get_user_pages_fast+0x84/0x120 [00000000006f5a18] iov_iter_get_pages+0x98/0x240 [00000000005fa744] do_direct_IO+0xf64/0x1e00 [00000000005fbbc0] __blockdev_direct_IO+0x360/0x15a0 [00000000101f74fc] ext4_ind_direct_IO+0xdc/0x400 [ext4] [00000000101af690] ext4_ext_direct_IO+0x1d0/0x2c0 [ext4] [00000000101af86c] ext4_direct_IO+0xec/0x220 [ext4] [0000000000553bd4] generic_file_read_iter+0x114/0x140 [00000000005bdc2c] __vfs_read+0xac/0x100 [00000000005bf254] vfs_read+0x54/0x100 [00000000005bf368] SyS_pread64+0x68/0x80 Signed-off-by: Tom Hromatka --- arch/sparc/include/asm/pgtable_64.h | 15 ++++++++------- 1 files changed, 8 insertions(+), 7 deletions(-) diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h index 8a59852..6fbd931 100644 --- a/arch/sparc/include/asm/pgtable_64.h +++ b/arch/sparc/include/asm/pgtable_64.h @@ -679,26 +679,27 @@ static inline unsigned long pmd_pfn(pmd_t pmd) return pte_pfn(pte); } -#ifdef CONFIG_TRANSPARENT_HUGEPAGE -static inline unsigned long pmd_dirty(pmd_t pmd) +#define __HAVE_ARCH_PMD_WRITE +static inline unsigned long pmd_write(pmd_t pmd) { pte_t pte = __pte(pmd_val(pmd)); - return pte_dirty(pte); + return pte_write(pte); } -static inline unsigned long pmd_young(pmd_t pmd) +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static inline unsigned long pmd_dirty(pmd_t pmd) { pte_t pte = __pte(pmd_val(pmd)); - return pte_young(pte); + return pte_dirty(pte); } -static inline unsigned long pmd_write(pmd_t pmd) +static inline unsigned long pmd_young(pmd_t pmd) { pte_t pte = __pte(pmd_val(pmd)); - return pte_write(pte); + return pte_young(pte); } static inline unsigned long pmd_trans_huge(pmd_t pmd) -- 1.7.1