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From: Martin Schwidefsky <schwidefsky@de.ibm.com>
To: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: [patch 05/18] DEBUG_PAGEALLOC support for s390.
Date: Tue, 05 Feb 2008 16:38:40 +0100	[thread overview]
Message-ID: <20080205153911.833313640@de.ibm.com> (raw)
In-Reply-To: <20080205153835.337897404@de.ibm.com>

[-- Attachment #1: 005-debug-pagealloc.diff --]
[-- Type: text/plain, Size: 2934 bytes --]

From: Heiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 arch/s390/Kconfig.debug       |    8 ++++++++
 arch/s390/kernel/traps.c      |    5 ++++-
 arch/s390/mm/init.c           |   27 +++++++++++++++++++++++++++
 include/asm-s390/cacheflush.h |    4 ++++
 4 files changed, 43 insertions(+), 1 deletion(-)

Index: quilt-2.6/arch/s390/Kconfig.debug
===================================================================
--- quilt-2.6.orig/arch/s390/Kconfig.debug
+++ quilt-2.6/arch/s390/Kconfig.debug
@@ -6,4 +6,12 @@ config TRACE_IRQFLAGS_SUPPORT
 
 source "lib/Kconfig.debug"
 
+config DEBUG_PAGEALLOC
+	bool "Debug page memory allocations"
+	depends on DEBUG_KERNEL
+	help
+	  Unmap pages from the kernel linear mapping after free_pages().
+	  This results in a slowdown, but helps to find certain types of
+	  memory corruptions.
+
 endmenu
Index: quilt-2.6/arch/s390/kernel/traps.c
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/traps.c
+++ quilt-2.6/arch/s390/kernel/traps.c
@@ -271,7 +271,10 @@ void die(const char * str, struct pt_reg
 	printk("PREEMPT ");
 #endif
 #ifdef CONFIG_SMP
-	printk("SMP");
+	printk("SMP ");
+#endif
+#ifdef CONFIG_DEBUG_PAGEALLOC
+	printk("DEBUG_PAGEALLOC");
 #endif
 	printk("\n");
 	notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
Index: quilt-2.6/arch/s390/mm/init.c
===================================================================
--- quilt-2.6.orig/arch/s390/mm/init.c
+++ quilt-2.6/arch/s390/mm/init.c
@@ -167,6 +167,33 @@ void __init mem_init(void)
 	       PFN_ALIGN((unsigned long)&_eshared) - 1);
 }
 
+#ifdef CONFIG_DEBUG_PAGEALLOC
+void kernel_map_pages(struct page *page, int numpages, int enable)
+{
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+	unsigned long address;
+	int i;
+
+	for (i = 0; i < numpages; i++) {
+		address = page_to_phys(page + i);
+		pgd = pgd_offset_k(address);
+		pud = pud_offset(pgd, address);
+		pmd = pmd_offset(pud, address);
+		pte = pte_offset_kernel(pmd, address);
+		if (!enable) {
+			ptep_invalidate(address, pte);
+			continue;
+		}
+		*pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW));
+		/* Flush cpu write queue. */
+		mb();
+	}
+}
+#endif
+
 void free_initmem(void)
 {
         unsigned long addr;
Index: quilt-2.6/include/asm-s390/cacheflush.h
===================================================================
--- quilt-2.6.orig/include/asm-s390/cacheflush.h
+++ quilt-2.6/include/asm-s390/cacheflush.h
@@ -24,4 +24,8 @@
 #define copy_from_user_page(vma, page, vaddr, dst, src, len) \
 	memcpy(dst, src, len)
 
+#ifdef CONFIG_DEBUG_PAGEALLOC
+void kernel_map_pages(struct page *page, int numpages, int enable);
+#endif
+
 #endif /* _S390_CACHEFLUSH_H */

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.


  parent reply	other threads:[~2008-02-05 15:40 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-05 15:38 [patch 00/18] s390 bug fix patches Martin Schwidefsky
2008-02-05 15:38 ` [patch 01/18] cio: make sense id procedure work with partial hardware response Martin Schwidefsky
2008-02-05 15:38 ` [patch 02/18] cio: Clean up chsc response code handling Martin Schwidefsky
2008-02-05 15:38 ` [patch 03/18] cio: Update documentation Martin Schwidefsky
2008-02-05 15:38 ` [patch 04/18] cio: Add shutdown callback for ccwgroup Martin Schwidefsky
2008-02-05 15:38 ` Martin Schwidefsky [this message]
2008-02-05 15:38 ` [patch 06/18] Fix linker script Martin Schwidefsky
2008-02-05 15:38 ` [patch 07/18] Fix smp_call_function_mask semantics Martin Schwidefsky
2008-02-05 15:38 ` [patch 08/18] Fix couple of section mismatches Martin Schwidefsky
2008-02-05 15:38 ` [patch 09/18] console: allow vt220 console to be the only console Martin Schwidefsky
2008-02-05 15:38 ` [patch 10/18] Define GENERIC_LOCKBREAK Martin Schwidefsky
2008-02-05 15:38 ` [patch 11/18] Cleanup & optimize bitops Martin Schwidefsky
2008-02-05 15:38 ` [patch 12/18] Implement ext2_find_next_bit Martin Schwidefsky
2008-02-05 15:38 ` [patch 13/18] latencytop s390 support Martin Schwidefsky
2008-02-05 15:38 ` [patch 14/18] dasd: add ifcc handling Martin Schwidefsky
2008-02-05 15:38 ` [patch 15/18] dasd: fix panic caused by alias device offline Martin Schwidefsky
2008-02-05 15:38 ` [patch 16/18] sclp_tty/sclp_vt220: Fix scheduling while atomic Martin Schwidefsky
2008-02-05 15:38 ` [patch 17/18] Remove BUILD_BUG_ON() in vmem code Martin Schwidefsky
2008-02-05 15:38 ` [patch 18/18] dcss: Initialize workqueue before using it Martin Schwidefsky
2008-02-05 15:45   ` Carsten Otte

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