The patch titled
Subject: vmcore: copy non page-size aligned head and tail pages in 2nd kernel
has been added to the -mm tree. Its filename is
vmcore-copy-non-page-size-aligned-head-and-tail-pages-in-2nd-kernel.patch
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The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: HATAYAMA Daisuke <d.hatayama@xxxxxxxxxxxxxx>
Subject: vmcore: copy non page-size aligned head and tail pages in 2nd kernel
Due to mmap() requirement, we need to copy pages not starting or ending
with page-size aligned address in 2nd kernel and to map them to
user-space.
For example, see the map below:
00000000-00010000 : reserved
00010000-0009f800 : System RAM
0009f800-000a0000 : reserved
where the System RAM ends with 0x9f800 that is not page-size aligned.
This map is divided into two parts:
00010000-0009f000
0009f000-0009f800
and the first one is kept in old memory and the 2nd one is copied into
buffer on 2nd kernel.
This kind of non-page-size-aligned area can always occur since any part of
System RAM can be converted into reserved area at runtime.
If not doing copying like this and if remapping non page-size aligned
pages on old memory directly, mmap() had to export memory which is not
dump target to user-space. In the above example this is reserved
0x9f800-0xa0000.
Signed-off-by: HATAYAMA Daisuke <d.hatayama@xxxxxxxxxxxxxx>
Cc: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/vmcore.c | 192 ++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 172 insertions(+), 20 deletions(-)
diff -puN fs/proc/vmcore.c~vmcore-copy-non-page-size-aligned-head-and-tail-pages-in-2nd-kernel fs/proc/vmcore.c
--- a/fs/proc/vmcore.c~vmcore-copy-non-page-size-aligned-head-and-tail-pages-in-2nd-kernel
+++ a/fs/proc/vmcore.c
@@ -472,11 +472,10 @@ static int __init process_ptload_program
size_t elfsz,
struct list_head *vc_list)
{
- int i;
+ int i, rc;
Elf64_Ehdr *ehdr_ptr;
Elf64_Phdr *phdr_ptr;
loff_t vmcore_off;
- struct vmcore *new;
ehdr_ptr = (Elf64_Ehdr *)elfptr;
phdr_ptr = (Elf64_Phdr*)(elfptr + ehdr_ptr->e_phoff); /* PT_NOTE hdr */
@@ -486,20 +485,97 @@ static int __init process_ptload_program
PAGE_SIZE);
for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+ u64 start, end, rest;
+
if (phdr_ptr->p_type != PT_LOAD)
continue;
- /* Add this contiguous chunk of memory to vmcore list.*/
- new = get_new_element();
- if (!new)
- return -ENOMEM;
- new->paddr = phdr_ptr->p_offset;
- new->size = phdr_ptr->p_memsz;
- list_add_tail(&new->list, vc_list);
+ start = phdr_ptr->p_offset;
+ end = phdr_ptr->p_offset + phdr_ptr->p_memsz;
+ rest = phdr_ptr->p_memsz;
+
+ if (start & ~PAGE_MASK) {
+ u64 paddr, len;
+ char *buf;
+ struct vmcore *new;
+
+ paddr = start;
+ len = min(roundup(start,PAGE_SIZE), end) - start;
+
+ buf = (char *)get_zeroed_page(GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+ rc = read_from_oldmem(buf + (start & ~PAGE_MASK), len,
+ &paddr, 0);
+ if (rc < 0) {
+ free_pages((unsigned long)buf, 0);
+ return rc;
+ }
+
+ new = get_new_element();
+ if (!new) {
+ free_pages((unsigned long)buf, 0);
+ return -ENOMEM;
+ }
+ new->flag |= MEM_TYPE_CURRENT_KERNEL;
+ new->size = PAGE_SIZE;
+ new->buf = buf;
+ list_add_tail(&new->list, vc_list);
+
+ rest -= len;
+ }
+
+ if (rest > 0 &&
+ roundup(start, PAGE_SIZE) < rounddown(end, PAGE_SIZE)) {
+ u64 paddr, len;
+ struct vmcore *new;
+
+ paddr = roundup(start, PAGE_SIZE);
+ len =rounddown(end,PAGE_SIZE)-roundup(start,PAGE_SIZE);
+
+ new = get_new_element();
+ if (!new)
+ return -ENOMEM;
+ new->paddr = paddr;
+ new->size = len;
+ list_add_tail(&new->list, vc_list);
+
+ rest -= len;
+ }
+
+ if (rest > 0) {
+ u64 paddr, len;
+ char *buf;
+ struct vmcore *new;
+
+ paddr = rounddown(end, PAGE_SIZE);
+ len = end - rounddown(end, PAGE_SIZE);
+
+ buf = (char *)get_zeroed_page(GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+ rc = read_from_oldmem(buf, len, &paddr, 0);
+ if (rc < 0) {
+ free_pages((unsigned long)buf, 0);
+ return rc;
+ }
+
+ new = get_new_element();
+ if (!new) {
+ free_pages((unsigned long)buf, 0);
+ return -ENOMEM;
+ }
+ new->flag |= MEM_TYPE_CURRENT_KERNEL;
+ new->size = PAGE_SIZE;
+ new->buf = buf;
+ list_add_tail(&new->list, vc_list);
+
+ rest -= len;
+ }
/* Update the program header offset. */
phdr_ptr->p_offset = vmcore_off;
- vmcore_off = vmcore_off + phdr_ptr->p_memsz;
+ vmcore_off +=roundup(end,PAGE_SIZE)-rounddown(start,PAGE_SIZE);
}
return 0;
}
@@ -508,11 +584,10 @@ static int __init process_ptload_program
size_t elfsz,
struct list_head *vc_list)
{
- int i;
+ int i, rc;
Elf32_Ehdr *ehdr_ptr;
Elf32_Phdr *phdr_ptr;
loff_t vmcore_off;
- struct vmcore *new;
ehdr_ptr = (Elf32_Ehdr *)elfptr;
phdr_ptr = (Elf32_Phdr*)(elfptr + ehdr_ptr->e_phoff); /* PT_NOTE hdr */
@@ -522,20 +597,97 @@ static int __init process_ptload_program
PAGE_SIZE);
for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
+ u64 start, end, rest;
+
if (phdr_ptr->p_type != PT_LOAD)
continue;
- /* Add this contiguous chunk of memory to vmcore list.*/
- new = get_new_element();
- if (!new)
- return -ENOMEM;
- new->paddr = phdr_ptr->p_offset;
- new->size = phdr_ptr->p_memsz;
- list_add_tail(&new->list, vc_list);
+ start = phdr_ptr->p_offset;
+ end = phdr_ptr->p_offset + phdr_ptr->p_memsz;
+ rest = phdr_ptr->p_memsz;
+
+ if (start & ~PAGE_MASK) {
+ u64 paddr, len;
+ char *buf;
+ struct vmcore *new;
+
+ paddr = start;
+ len = min(roundup(start,PAGE_SIZE), end) - start;
+
+ buf = (char *)get_zeroed_page(GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+ rc = read_from_oldmem(buf + (start & ~PAGE_MASK), len,
+ &paddr, 0);
+ if (rc < 0) {
+ free_pages((unsigned long)buf, 0);
+ return rc;
+ }
+
+ new = get_new_element();
+ if (!new) {
+ free_pages((unsigned long)buf, 0);
+ return -ENOMEM;
+ }
+ new->flag |= MEM_TYPE_CURRENT_KERNEL;
+ new->size = PAGE_SIZE;
+ new->buf = buf;
+ list_add_tail(&new->list, vc_list);
+
+ rest -= len;
+ }
+
+ if (rest > 0 &&
+ roundup(start, PAGE_SIZE) < rounddown(end, PAGE_SIZE)) {
+ u64 paddr, len;
+ struct vmcore *new;
+
+ paddr = roundup(start, PAGE_SIZE);
+ len =rounddown(end,PAGE_SIZE)-roundup(start,PAGE_SIZE);
+
+ new = get_new_element();
+ if (!new)
+ return -ENOMEM;
+ new->paddr = paddr;
+ new->size = len;
+ list_add_tail(&new->list, vc_list);
+
+ rest -= len;
+ }
+
+ if (rest > 0) {
+ u64 paddr, len;
+ char *buf;
+ struct vmcore *new;
+
+ paddr = rounddown(end, PAGE_SIZE);
+ len = end - rounddown(end, PAGE_SIZE);
+
+ buf = (char *)get_zeroed_page(GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+ rc = read_from_oldmem(buf, len, &paddr, 0);
+ if (rc < 0) {
+ free_pages((unsigned long)buf, 0);
+ return rc;
+ }
+
+ new = get_new_element();
+ if (!new) {
+ free_pages((unsigned long)buf, 0);
+ return -ENOMEM;
+ }
+ new->flag |= MEM_TYPE_CURRENT_KERNEL;
+ new->size = PAGE_SIZE;
+ new->buf = buf;
+ list_add_tail(&new->list, vc_list);
+
+ rest -= len;
+ }
/* Update the program header offset */
phdr_ptr->p_offset = vmcore_off;
- vmcore_off = vmcore_off + phdr_ptr->p_memsz;
+ vmcore_off +=roundup(end,PAGE_SIZE)-rounddown(start,PAGE_SIZE);
}
return 0;
}
_
Patches currently in -mm which might be from d.hatayama@xxxxxxxxxxxxxx are
vmcore-reference-e_phoff-member-explicitly-to-get-position-of-program-header-table.patch
vmcore-clean-up-by-removing-unnecessary-variable.patch
vmcore-rearrange-program-headers-without-assuming-consequtive-pt_note-entries.patch
vmcore-sysfs-export-elf-note-segment-size-instead-of-vmcoreinfo-data-size.patch
vmcore-allocate-buffer-for-elf-headers-on-page-size-alignment.patch
vmcore-round-up-buffer-size-of-elf-headers-by-page_size.patch
vmcore-procfs-introduce-a-flag-to-distinguish-objects-copied-in-2nd-kernel.patch
vmcore-copy-non-page-size-aligned-head-and-tail-pages-in-2nd-kernel.patch
vmcore-modify-vmcore-clean-up-function-to-free-buffer-on-2nd-kernel.patch
vmcore-clean-up-read_vmcore.patch
vmcore-read-buffers-for-vmcore-objects-copied-from-old-memory.patch
vmcore-allocate-per-cpu-crash_notes-objects-on-page-size-boundary.patch
kexec-allocate-vmcoreinfo-note-buffer-on-page-size-boundary.patch
kexec-elf-introduce-nt_vmcore_debuginfo-note-type.patch
elf-introduce-nt_vmcore_pad-type.patch
kexec-fill-note-buffers-by-nt_vmcore_pad-notes-in-page-size-boundary.patch
vmcore-check-nt_vmcore_pad-as-a-mark-indicating-the-end-of-elf-note-buffer.patch
vmcore-check-if-vmcore-objects-satify-mmaps-page-size-boundary-requirement.patch
vmcore-round-up-offset-of-vmcore-object-in-page-size-boundary.patch
vmcore-count-holes-generated-by-round-up-operation-for-vmcore-size.patch
vmcore-introduce-mmap_vmcore.patch
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