diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-08 15:57:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-08 15:57:47 -0700 |
| commit | 8065be8d032f38da25b54bf077a05a30d9ce9f2a (patch) | |
| tree | 32a7baf4b40e0240ab4b9dd6f2bbe6129929bb66 /fs/proc/vmcore.c | |
| parent | 27d438c56009e5ae632de36fe70985d1aab5e344 (diff) | |
| parent | ecc265fe9e09e32a3573b2ba26e79b2099eb8bbb (diff) | |
Merge branch 'akpm' (second patchbomb from Andrew Morton)
Merge more incoming from Andrew Morton:
"Two new syscalls:
memfd_create in "shm: add memfd_create() syscall"
kexec_file_load in "kexec: implementation of new syscall kexec_file_load"
And:
- Most (all?) of the rest of MM
- Lots of the usual misc bits
- fs/autofs4
- drivers/rtc
- fs/nilfs
- procfs
- fork.c, exec.c
- more in lib/
- rapidio
- Janitorial work in filesystems: fs/ufs, fs/reiserfs, fs/adfs,
fs/cramfs, fs/romfs, fs/qnx6.
- initrd/initramfs work
- "file sealing" and the memfd_create() syscall, in tmpfs
- add pci_zalloc_consistent, use it in lots of places
- MAINTAINERS maintenance
- kexec feature work"
* emailed patches from Andrew Morton <akpm@linux-foundation.org: (193 commits)
MAINTAINERS: update nomadik patterns
MAINTAINERS: update usb/gadget patterns
MAINTAINERS: update DMA BUFFER SHARING patterns
kexec: verify the signature of signed PE bzImage
kexec: support kexec/kdump on EFI systems
kexec: support for kexec on panic using new system call
kexec-bzImage64: support for loading bzImage using 64bit entry
kexec: load and relocate purgatory at kernel load time
purgatory: core purgatory functionality
purgatory/sha256: provide implementation of sha256 in purgaotory context
kexec: implementation of new syscall kexec_file_load
kexec: new syscall kexec_file_load() declaration
kexec: make kexec_segment user buffer pointer a union
resource: provide new functions to walk through resources
kexec: use common function for kimage_normal_alloc() and kimage_crash_alloc()
kexec: move segment verification code in a separate function
kexec: rename unusebale_pages to unusable_pages
kernel: build bin2c based on config option CONFIG_BUILD_BIN2C
bin2c: move bin2c in scripts/basic
shm: wait for pins to be released when sealing
...
Diffstat (limited to 'fs/proc/vmcore.c')
| -rw-r--r-- | fs/proc/vmcore.c | 82 |
1 files changed, 79 insertions, 3 deletions
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 382aa890e228..a90d6d354199 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -328,6 +328,82 @@ static inline char *alloc_elfnotes_buf(size_t notes_sz) * virtually contiguous user-space in ELF layout. */ #ifdef CONFIG_MMU +/* + * remap_oldmem_pfn_checked - do remap_oldmem_pfn_range replacing all pages + * reported as not being ram with the zero page. + * + * @vma: vm_area_struct describing requested mapping + * @from: start remapping from + * @pfn: page frame number to start remapping to + * @size: remapping size + * @prot: protection bits + * + * Returns zero on success, -EAGAIN on failure. + */ +static int remap_oldmem_pfn_checked(struct vm_area_struct *vma, + unsigned long from, unsigned long pfn, + unsigned long size, pgprot_t prot) +{ + unsigned long map_size; + unsigned long pos_start, pos_end, pos; + unsigned long zeropage_pfn = my_zero_pfn(0); + size_t len = 0; + + pos_start = pfn; + pos_end = pfn + (size >> PAGE_SHIFT); + + for (pos = pos_start; pos < pos_end; ++pos) { + if (!pfn_is_ram(pos)) { + /* + * We hit a page which is not ram. Remap the continuous + * region between pos_start and pos-1 and replace + * the non-ram page at pos with the zero page. + */ + if (pos > pos_start) { + /* Remap continuous region */ + map_size = (pos - pos_start) << PAGE_SHIFT; + if (remap_oldmem_pfn_range(vma, from + len, + pos_start, map_size, + prot)) + goto fail; + len += map_size; + } + /* Remap the zero page */ + if (remap_oldmem_pfn_range(vma, from + len, + zeropage_pfn, + PAGE_SIZE, prot)) + goto fail; + len += PAGE_SIZE; + pos_start = pos + 1; + } + } + if (pos > pos_start) { + /* Remap the rest */ + map_size = (pos - pos_start) << PAGE_SHIFT; + if (remap_oldmem_pfn_range(vma, from + len, pos_start, + map_size, prot)) + goto fail; + } + return 0; +fail: + do_munmap(vma->vm_mm, from, len); + return -EAGAIN; +} + +static int vmcore_remap_oldmem_pfn(struct vm_area_struct *vma, + unsigned long from, unsigned long pfn, + unsigned long size, pgprot_t prot) +{ + /* + * Check if oldmem_pfn_is_ram was registered to avoid + * looping over all pages without a reason. + */ + if (oldmem_pfn_is_ram) + return remap_oldmem_pfn_checked(vma, from, pfn, size, prot); + else + return remap_oldmem_pfn_range(vma, from, pfn, size, prot); +} + static int mmap_vmcore(struct file *file, struct vm_area_struct *vma) { size_t size = vma->vm_end - vma->vm_start; @@ -387,9 +463,9 @@ static int mmap_vmcore(struct file *file, struct vm_area_struct *vma) tsz = min_t(size_t, m->offset + m->size - start, size); paddr = m->paddr + start - m->offset; - if (remap_oldmem_pfn_range(vma, vma->vm_start + len, - paddr >> PAGE_SHIFT, tsz, - vma->vm_page_prot)) + if (vmcore_remap_oldmem_pfn(vma, vma->vm_start + len, + paddr >> PAGE_SHIFT, tsz, + vma->vm_page_prot)) goto fail; size -= tsz; start += tsz; |