Commit 26562c59fa9111ae3ea7b78045889662aac9e5ac
Committed by
Linus Torvalds
Linus Torvalds
1 parent
3089aa1b0c
Exists in
master
and in
7 other branches
kcore: register vmemmap range
Benjamin Herrenschmidt <benh@kernel.crashing.org> pointed out that vmemmap range is not included in KCORE_RAM, KCORE_VMALLOC .... This adds KCORE_VMEMMAP if SPARSEMEM_VMEMMAP is used. By this, vmemmap can be readable via /proc/kcore Because it's not vmalloc area, vread/vwrite cannot be used. But the range is static against the memory layout, this patch handles vmemmap area by the same scheme with physical memory. This patch assumes SPARSEMEM_VMEMMAP range is not in VMALLOC range. It's correct now. [akpm@linux-foundation.org: fix typo] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: WANG Cong <xiyou.wangcong@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Showing 2 changed files with 51 additions and 2 deletions Side-by-side Diff
fs/proc/kcore.c
| ... | ... | @@ -103,7 +103,7 @@ |
| 103 | 103 | } |
| 104 | 104 | } |
| 105 | 105 | /* |
| 106 | - * Replace all KCORE_RAM information with passed list. | |
| 106 | + * Replace all KCORE_RAM/KCORE_VMEMMAP information with passed list. | |
| 107 | 107 | */ |
| 108 | 108 | static void __kcore_update_ram(struct list_head *list) |
| 109 | 109 | { |
| ... | ... | @@ -113,7 +113,8 @@ |
| 113 | 113 | write_lock(&kclist_lock); |
| 114 | 114 | if (kcore_need_update) { |
| 115 | 115 | list_for_each_entry_safe(pos, tmp, &kclist_head, list) { |
| 116 | - if (pos->type == KCORE_RAM) | |
| 116 | + if (pos->type == KCORE_RAM | |
| 117 | + || pos->type == KCORE_VMEMMAP) | |
| 117 | 118 | list_move(&pos->list, &garbage); |
| 118 | 119 | } |
| 119 | 120 | list_splice_tail(list, &kclist_head); |
| ... | ... | @@ -151,6 +152,47 @@ |
| 151 | 152 | |
| 152 | 153 | #else /* !CONFIG_HIGHMEM */ |
| 153 | 154 | |
| 155 | +#ifdef CONFIG_SPARSEMEM_VMEMMAP | |
| 156 | +/* calculate vmemmap's address from given system ram pfn and register it */ | |
| 157 | +int get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head) | |
| 158 | +{ | |
| 159 | + unsigned long pfn = __pa(ent->addr) >> PAGE_SHIFT; | |
| 160 | + unsigned long nr_pages = ent->size >> PAGE_SHIFT; | |
| 161 | + unsigned long start, end; | |
| 162 | + struct kcore_list *vmm, *tmp; | |
| 163 | + | |
| 164 | + | |
| 165 | + start = ((unsigned long)pfn_to_page(pfn)) & PAGE_MASK; | |
| 166 | + end = ((unsigned long)pfn_to_page(pfn + nr_pages)) - 1; | |
| 167 | + end = ALIGN(end, PAGE_SIZE); | |
| 168 | + /* overlap check (because we have to align page */ | |
| 169 | + list_for_each_entry(tmp, head, list) { | |
| 170 | + if (tmp->type != KCORE_VMEMMAP) | |
| 171 | + continue; | |
| 172 | + if (start < tmp->addr + tmp->size) | |
| 173 | + if (end > tmp->addr) | |
| 174 | + end = tmp->addr; | |
| 175 | + } | |
| 176 | + if (start < end) { | |
| 177 | + vmm = kmalloc(sizeof(*vmm), GFP_KERNEL); | |
| 178 | + if (!vmm) | |
| 179 | + return 0; | |
| 180 | + vmm->addr = start; | |
| 181 | + vmm->size = end - start; | |
| 182 | + vmm->type = KCORE_VMEMMAP; | |
| 183 | + list_add_tail(&vmm->list, head); | |
| 184 | + } | |
| 185 | + return 1; | |
| 186 | + | |
| 187 | +} | |
| 188 | +#else | |
| 189 | +int get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head) | |
| 190 | +{ | |
| 191 | + return 1; | |
| 192 | +} | |
| 193 | + | |
| 194 | +#endif | |
| 195 | + | |
| 154 | 196 | static int |
| 155 | 197 | kclist_add_private(unsigned long pfn, unsigned long nr_pages, void *arg) |
| 156 | 198 | { |
| ... | ... | @@ -181,6 +223,12 @@ |
| 181 | 223 | |
| 182 | 224 | ent->type = KCORE_RAM; |
| 183 | 225 | list_add_tail(&ent->list, head); |
| 226 | + | |
| 227 | + if (!get_sparsemem_vmemmap_info(ent, head)) { | |
| 228 | + list_del(&ent->list); | |
| 229 | + goto free_out; | |
| 230 | + } | |
| 231 | + | |
| 184 | 232 | return 0; |
| 185 | 233 | free_out: |
| 186 | 234 | kfree(ent); |