diff options
| -rw-r--r-- | arch/s390/Kconfig.debug | 8 | ||||
| -rw-r--r-- | arch/s390/kernel/traps.c | 5 | ||||
| -rw-r--r-- | arch/s390/mm/init.c | 27 | ||||
| -rw-r--r-- | include/asm-s390/cacheflush.h | 4 |
4 files changed, 43 insertions, 1 deletions
diff --git a/arch/s390/Kconfig.debug b/arch/s390/Kconfig.debug index 2283933a9a93..4599fa06bd82 100644 --- a/arch/s390/Kconfig.debug +++ b/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 diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c index 52b8342c6bf2..1a2fdb6991df 100644 --- a/arch/s390/kernel/traps.c +++ b/arch/s390/kernel/traps.c @@ -271,7 +271,10 @@ void die(const char * str, struct pt_regs * regs, long err) 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); diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index b234bb4a6da7..983ec6ec0e7c 100644 --- a/arch/s390/mm/init.c +++ b/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; diff --git a/include/asm-s390/cacheflush.h b/include/asm-s390/cacheflush.h index f7cade8083f3..49d5af916d01 100644 --- a/include/asm-s390/cacheflush.h +++ b/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 */ |