From: HATAYAMA Daisuke <d.hatayama@gmail.com> To: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Vivek Goyal <vgoyal@redhat.com>, Jan Willeke <willeke@de.ibm.com>, Martin Schwidefsky <schwidefsky@de.ibm.com>, Heiko Carstens <heiko.carstens@de.ibm.com>, linux-kernel@vger.kernel.org, kexec@lists.infradead.org Subject: Re: [PATCH v5 3/5] vmcore: Introduce remap_oldmem_pfn_range() Date: Tue, 11 Jun 2013 22:20:22 +0900 [thread overview] Message-ID: <CABOkKT3ir=bRAmD-pgQOsM_EfPsThtzVnhhY16e_A3suBe5sgg@mail.gmail.com> (raw) In-Reply-To: <20130610173739.4d88d4ec@holzheu> 2013/6/11 Michael Holzheu <holzheu@linux.vnet.ibm.com>: > On Mon, 10 Jun 2013 22:40:24 +0900 > HATAYAMA Daisuke <d.hatayama@gmail.com> wrote: > >> 2013/6/8 Michael Holzheu <holzheu@linux.vnet.ibm.com>: >> <cut> >> > @@ -225,6 +251,56 @@ static ssize_t read_vmcore(struct file *file, char __user *buffer, >> > return acc; >> > } >> > >> > +static ssize_t read_vmcore(struct file *file, char __user *buffer, >> > + size_t buflen, loff_t *fpos) >> > +{ >> > + return __read_vmcore(buffer, buflen, fpos, 1); >> > +} >> > + >> > +/* >> > + * The vmcore fault handler uses the page cache and fills data using the >> > + * standard __vmcore_read() function. >> > + */ >> > +static int mmap_vmcore_fault(struct vm_area_struct *vma, struct vm_fault *vmf) >> > +{ >> > + struct address_space *mapping = vma->vm_private_data; >> > + pgoff_t index = vmf->pgoff; >> > + struct page *page; >> > + loff_t src; >> > + char *buf; >> > + int rc; >> > + >> > +find_page: >> > + page = find_lock_page(mapping, index); >> > + if (page) { >> > + unlock_page(page); >> > + rc = VM_FAULT_MINOR; >> > + } else { >> > + page = page_cache_alloc_cold(mapping); >> > + if (!page) >> > + return VM_FAULT_OOM; >> > + rc = add_to_page_cache_lru(page, mapping, index, GFP_KERNEL); >> > + if (rc) { >> > + page_cache_release(page); >> > + if (rc == -EEXIST) >> > + goto find_page; >> > + /* Probably ENOMEM for radix tree node */ >> > + return VM_FAULT_OOM; >> > + } >> > + buf = (void *) (page_to_pfn(page) << PAGE_SHIFT); >> > + src = index << PAGE_CACHE_SHIFT; >> > + __read_vmcore(buf, PAGE_SIZE, &src, 0); >> > + unlock_page(page); >> > + rc = VM_FAULT_MAJOR; >> > + } >> > + vmf->page = page; >> > + return rc; >> > +} >> >> How about reusing find_or_create_page()? > > The function would then look like the following: > > static int mmap_vmcore_fault(struct vm_area_struct *vma, struct vm_fault *vmf) > { > struct address_space *mapping = vma->vm_private_data; > pgoff_t index = vmf->pgoff; > struct page *page; > loff_t src; > char *buf; > > page = find_or_create_page(mapping, index, GFP_KERNEL); > if (!page) > return VM_FAULT_OOM; > src = index << PAGE_CACHE_SHIFT; > buf = (void *) (page_to_pfn(page) << PAGE_SHIFT); > __read_vmcore(buf, PAGE_SIZE, &src, 0); You should check return value of __read_vmcore() since this can fail. Then, I think returning VM_FAULT_SIGBUS is correct. > unlock_page(page); > vmf->page = page; > return 0; > } Thanks. HATAYAMA, Daisuke
WARNING: multiple messages have this Message-ID (diff)
From: HATAYAMA Daisuke <d.hatayama@gmail.com> To: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>, kexec@lists.infradead.org, Jan Willeke <willeke@de.ibm.com>, linux-kernel@vger.kernel.org, Martin Schwidefsky <schwidefsky@de.ibm.com>, Vivek Goyal <vgoyal@redhat.com> Subject: Re: [PATCH v5 3/5] vmcore: Introduce remap_oldmem_pfn_range() Date: Tue, 11 Jun 2013 22:20:22 +0900 [thread overview] Message-ID: <CABOkKT3ir=bRAmD-pgQOsM_EfPsThtzVnhhY16e_A3suBe5sgg@mail.gmail.com> (raw) In-Reply-To: <20130610173739.4d88d4ec@holzheu> 2013/6/11 Michael Holzheu <holzheu@linux.vnet.ibm.com>: > On Mon, 10 Jun 2013 22:40:24 +0900 > HATAYAMA Daisuke <d.hatayama@gmail.com> wrote: > >> 2013/6/8 Michael Holzheu <holzheu@linux.vnet.ibm.com>: >> <cut> >> > @@ -225,6 +251,56 @@ static ssize_t read_vmcore(struct file *file, char __user *buffer, >> > return acc; >> > } >> > >> > +static ssize_t read_vmcore(struct file *file, char __user *buffer, >> > + size_t buflen, loff_t *fpos) >> > +{ >> > + return __read_vmcore(buffer, buflen, fpos, 1); >> > +} >> > + >> > +/* >> > + * The vmcore fault handler uses the page cache and fills data using the >> > + * standard __vmcore_read() function. >> > + */ >> > +static int mmap_vmcore_fault(struct vm_area_struct *vma, struct vm_fault *vmf) >> > +{ >> > + struct address_space *mapping = vma->vm_private_data; >> > + pgoff_t index = vmf->pgoff; >> > + struct page *page; >> > + loff_t src; >> > + char *buf; >> > + int rc; >> > + >> > +find_page: >> > + page = find_lock_page(mapping, index); >> > + if (page) { >> > + unlock_page(page); >> > + rc = VM_FAULT_MINOR; >> > + } else { >> > + page = page_cache_alloc_cold(mapping); >> > + if (!page) >> > + return VM_FAULT_OOM; >> > + rc = add_to_page_cache_lru(page, mapping, index, GFP_KERNEL); >> > + if (rc) { >> > + page_cache_release(page); >> > + if (rc == -EEXIST) >> > + goto find_page; >> > + /* Probably ENOMEM for radix tree node */ >> > + return VM_FAULT_OOM; >> > + } >> > + buf = (void *) (page_to_pfn(page) << PAGE_SHIFT); >> > + src = index << PAGE_CACHE_SHIFT; >> > + __read_vmcore(buf, PAGE_SIZE, &src, 0); >> > + unlock_page(page); >> > + rc = VM_FAULT_MAJOR; >> > + } >> > + vmf->page = page; >> > + return rc; >> > +} >> >> How about reusing find_or_create_page()? > > The function would then look like the following: > > static int mmap_vmcore_fault(struct vm_area_struct *vma, struct vm_fault *vmf) > { > struct address_space *mapping = vma->vm_private_data; > pgoff_t index = vmf->pgoff; > struct page *page; > loff_t src; > char *buf; > > page = find_or_create_page(mapping, index, GFP_KERNEL); > if (!page) > return VM_FAULT_OOM; > src = index << PAGE_CACHE_SHIFT; > buf = (void *) (page_to_pfn(page) << PAGE_SHIFT); > __read_vmcore(buf, PAGE_SIZE, &src, 0); You should check return value of __read_vmcore() since this can fail. Then, I think returning VM_FAULT_SIGBUS is correct. > unlock_page(page); > vmf->page = page; > return 0; > } Thanks. HATAYAMA, Daisuke _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2013-06-11 13:20 UTC|newest] Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-06-07 16:55 [PATCH v5 0/5] kdump: Allow ELF header creation in new kernel Michael Holzheu 2013-06-07 16:55 ` Michael Holzheu 2013-06-07 16:55 ` [PATCH v5 1/5] vmcore: Introduce ELF header in new memory feature Michael Holzheu 2013-06-07 16:55 ` Michael Holzheu 2013-06-10 13:35 ` HATAYAMA Daisuke 2013-06-10 13:35 ` HATAYAMA Daisuke 2013-06-10 13:53 ` Michael Holzheu 2013-06-10 13:53 ` Michael Holzheu 2013-06-14 18:54 ` Vivek Goyal 2013-06-14 18:54 ` Vivek Goyal 2013-06-21 14:17 ` Michael Holzheu 2013-06-21 14:17 ` Michael Holzheu 2013-06-27 19:32 ` Vivek Goyal 2013-06-27 19:32 ` Vivek Goyal 2013-06-27 20:10 ` Cliff Wickman 2013-06-27 20:10 ` Cliff Wickman 2013-06-27 20:23 ` Vivek Goyal 2013-06-27 20:23 ` Vivek Goyal 2013-06-28 8:15 ` Michael Holzheu 2013-06-28 8:15 ` Michael Holzheu 2013-07-01 17:37 ` Vivek Goyal 2013-07-01 17:37 ` Vivek Goyal 2013-07-01 18:29 ` Michael Holzheu 2013-07-01 18:29 ` Michael Holzheu 2013-06-07 16:55 ` [PATCH v5 2/5] s390/vmcore: Use " Michael Holzheu 2013-06-07 16:55 ` Michael Holzheu 2013-06-10 13:36 ` HATAYAMA Daisuke 2013-06-10 13:36 ` HATAYAMA Daisuke 2013-06-10 13:48 ` Michael Holzheu 2013-06-10 13:48 ` Michael Holzheu 2013-06-14 19:16 ` Vivek Goyal 2013-06-14 19:16 ` Vivek Goyal 2013-06-07 16:55 ` [PATCH v5 3/5] vmcore: Introduce remap_oldmem_pfn_range() Michael Holzheu 2013-06-07 16:55 ` Michael Holzheu [not found] ` <CAJGZr0+_W0dp2f9VtVAiUT2fqiwe91gHXd9zYzfMMzBZSZogww@mail.gmail.com> 2013-06-10 8:00 ` Michael Holzheu 2013-06-10 8:00 ` Michael Holzheu 2013-06-10 13:40 ` HATAYAMA Daisuke 2013-06-10 13:40 ` HATAYAMA Daisuke 2013-06-10 14:03 ` Michael Holzheu 2013-06-10 14:03 ` Michael Holzheu 2013-06-10 15:37 ` Michael Holzheu 2013-06-10 15:37 ` Michael Holzheu 2013-06-11 12:42 ` HATAYAMA Daisuke 2013-06-11 12:42 ` HATAYAMA Daisuke 2013-06-12 9:13 ` Michael Holzheu 2013-06-12 9:13 ` Michael Holzheu 2013-06-13 1:32 ` HATAYAMA Daisuke 2013-06-13 1:32 ` HATAYAMA Daisuke 2013-06-13 8:54 ` Michael Holzheu 2013-06-13 8:54 ` Michael Holzheu 2013-06-13 4:00 ` HATAYAMA Daisuke 2013-06-13 4:00 ` HATAYAMA Daisuke 2013-06-11 13:20 ` HATAYAMA Daisuke [this message] 2013-06-11 13:20 ` HATAYAMA Daisuke 2013-06-07 16:56 ` [PATCH v5 4/5] s390/vmcore: Implement remap_oldmem_pfn_range for s390 Michael Holzheu 2013-06-07 16:56 ` Michael Holzheu 2013-06-14 20:08 ` Vivek Goyal 2013-06-14 20:08 ` Vivek Goyal 2013-06-07 16:56 ` [PATCH v5 5/5] s390/vmcore: Use vmcore for zfcpdump Michael Holzheu 2013-06-07 16:56 ` Michael Holzheu 2013-06-11 23:47 ` HATAYAMA Daisuke 2013-06-11 23:47 ` HATAYAMA Daisuke 2013-06-12 9:14 ` Michael Holzheu 2013-06-12 9:14 ` Michael Holzheu 2013-06-14 18:54 ` [PATCH v5 0/5] kdump: Allow ELF header creation in new kernel Vivek Goyal 2013-06-14 18:54 ` Vivek Goyal 2013-06-21 13:39 ` Michael Holzheu 2013-06-21 13:39 ` Michael Holzheu
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