在 2018年10月06日 19:47, tip-bot for Lianbo Jiang 写道: > Commit-ID: 992b649a3f013465d8128da02e5449def662a4c3 > Gitweb: > https://git.kernel.org/tip/992b649a3f013465d8128da02e5449def662a4c3 > Author: Lianbo Jiang <liji...@redhat.com> > AuthorDate: Sun, 30 Sep 2018 16:37:41 +0800 > Committer: Borislav Petkov <b...@suse.de> > CommitDate: Sat, 6 Oct 2018 12:09:26 +0200 > > kdump, proc/vmcore: Enable kdumping encrypted memory with SME enabled > > In the kdump kernel, the memory of the first kernel needs to be dumped > into the vmcore file. > > If SME is enabled in the first kernel, the old memory has to be remapped > with the memory encryption mask in order to access it properly. > > Split copy_oldmem_page() functionality to handle encrypted memory > properly. > > [ bp: Heavily massage everything. ] > > Signed-off-by: Lianbo Jiang <liji...@redhat.com> > Signed-off-by: Borislav Petkov <b...@suse.de> > Cc: ke...@lists.infradead.org > Cc: t...@linutronix.de > Cc: mi...@redhat.com > Cc: h...@zytor.com > Cc: a...@linux-foundation.org > Cc: dan.j.willi...@intel.com > Cc: bhelg...@google.com > Cc: baiyao...@cmss.chinamobile.com > Cc: ti...@suse.de > Cc: brijesh.si...@amd.com > Cc: dyo...@redhat.com > Cc: b...@redhat.com > Cc: jroe...@suse.de > Link: > https://lkml.kernel.org/r/be7b47f9-6be6-e0d1-2c2a-9125bc74b...@redhat.com > --- > arch/x86/kernel/crash_dump_64.c | 60 > ++++++++++++++++++++++++++++------------- > fs/proc/vmcore.c | 24 ++++++++++++----- > include/linux/crash_dump.h | 4 +++ > 3 files changed, 63 insertions(+), 25 deletions(-) > > diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c > index 4f2e0778feac..eb8ab3915268 100644 > --- a/arch/x86/kernel/crash_dump_64.c > +++ b/arch/x86/kernel/crash_dump_64.c > @@ -11,40 +11,62 @@ > #include <linux/uaccess.h> > #include <linux/io.h> > > -/** > - * copy_oldmem_page - copy one page from "oldmem" > - * @pfn: page frame number to be copied > - * @buf: target memory address for the copy; this can be in kernel address > - * space or user address space (see @userbuf) > - * @csize: number of bytes to copy > - * @offset: offset in bytes into the page (based on pfn) to begin the copy > - * @userbuf: if set, @buf is in user address space, use copy_to_user(), > - * otherwise @buf is in kernel address space, use memcpy(). > - * > - * Copy a page from "oldmem". For this page, there is no pte mapped > - * in the current kernel. We stitch up a pte, similar to kmap_atomic. > - */ > -ssize_t copy_oldmem_page(unsigned long pfn, char *buf, > - size_t csize, unsigned long offset, int userbuf) > +static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, > + unsigned long offset, int userbuf, > + bool encrypted) > { > void *vaddr; > > if (!csize) > return 0; > > - vaddr = ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE); > + if (encrypted) > + vaddr = (__force void *)ioremap_encrypted(pfn << PAGE_SHIFT, > PAGE_SIZE); > + else > + vaddr = (__force void *)ioremap_cache(pfn << PAGE_SHIFT, > PAGE_SIZE); > + > if (!vaddr) > return -ENOMEM; > > if (userbuf) { > - if (copy_to_user(buf, vaddr + offset, csize)) { > - iounmap(vaddr); > + if (copy_to_user((void __user *)buf, vaddr + offset, csize)) { > + iounmap((void __iomem *)vaddr); > return -EFAULT; > } > } else > memcpy(buf, vaddr + offset, csize); > > set_iounmap_nonlazy(); > - iounmap(vaddr); > + iounmap((void __iomem *)vaddr); > return csize; > } > + > +/** > + * copy_oldmem_page - copy one page of memory > + * @pfn: page frame number to be copied > + * @buf: target memory address for the copy; this can be in kernel address > + * space or user address space (see @userbuf) > + * @csize: number of bytes to copy > + * @offset: offset in bytes into the page (based on pfn) to begin the copy > + * @userbuf: if set, @buf is in user address space, use copy_to_user(), > + * otherwise @buf is in kernel address space, use memcpy(). > + * > + * Copy a page from the old kernel's memory. For this page, there is no pte > + * mapped in the current kernel. We stitch up a pte, similar to kmap_atomic. > + */ > +ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, > + unsigned long offset, int userbuf) > +{ > + return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, false); > +} > + > +/** > + * copy_oldmem_page_encrypted - same as copy_oldmem_page() above but ioremap > the > + * memory with the encryption mask set to accomodate kdump on SME-enabled > + * machines. > + */ > +ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t > csize, > + unsigned long offset, int userbuf) > +{ > + return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, true); > +} > diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c > index cbde728f8ac6..42c32d06f7da 100644 > --- a/fs/proc/vmcore.c > +++ b/fs/proc/vmcore.c > @@ -24,6 +24,8 @@ > #include <linux/vmalloc.h> > #include <linux/pagemap.h> > #include <linux/uaccess.h> > +#include <linux/mem_encrypt.h> > +#include <asm/pgtable.h> > #include <asm/io.h> > #include "internal.h" > > @@ -98,7 +100,8 @@ static int pfn_is_ram(unsigned long pfn) > > /* Reads a page from the oldmem device from given offset. */ > static ssize_t read_from_oldmem(char *buf, size_t count, > - u64 *ppos, int userbuf) > + u64 *ppos, int userbuf, > + bool encrypted) > { > unsigned long pfn, offset; > size_t nr_bytes; > @@ -120,8 +123,15 @@ static ssize_t read_from_oldmem(char *buf, size_t count, > if (pfn_is_ram(pfn) == 0) > memset(buf, 0, nr_bytes); > else { > - tmp = copy_oldmem_page(pfn, buf, nr_bytes, > - offset, userbuf); > + if (encrypted) > + tmp = copy_oldmem_page_encrypted(pfn, buf, > + nr_bytes, > + offset, > + userbuf); > + else > + tmp = copy_oldmem_page(pfn, buf, nr_bytes, > + offset, userbuf); > + > if (tmp < 0) > return tmp; > } > @@ -155,7 +165,7 @@ void __weak elfcorehdr_free(unsigned long long addr) > */ > ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos) > { > - return read_from_oldmem(buf, count, ppos, 0); > + return read_from_oldmem(buf, count, ppos, 0, false); > } > > /* > @@ -163,7 +173,7 @@ ssize_t __weak elfcorehdr_read(char *buf, size_t count, > u64 *ppos) > */ > ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos) > { > - return read_from_oldmem(buf, count, ppos, 0); > + return read_from_oldmem(buf, count, ppos, 0, sme_active()); > } > > /* > @@ -173,6 +183,7 @@ int __weak remap_oldmem_pfn_range(struct vm_area_struct > *vma, > unsigned long from, unsigned long pfn, > unsigned long size, pgprot_t prot) > { > + prot = pgprot_encrypted(prot); > return remap_pfn_range(vma, from, pfn, size, prot); > } > > @@ -351,7 +362,8 @@ static ssize_t __read_vmcore(char *buffer, size_t buflen, > loff_t *fpos, > m->offset + m->size - *fpos, > buflen); > start = m->paddr + *fpos - m->offset; > - tmp = read_from_oldmem(buffer, tsz, &start, userbuf); > + tmp = read_from_oldmem(buffer, tsz, &start, > + userbuf, sme_active()); > if (tmp < 0) > return tmp; > buflen -= tsz; > diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h > index 3e4ba9d753c8..f774c5eb9e3c 100644 > --- a/include/linux/crash_dump.h > +++ b/include/linux/crash_dump.h > @@ -26,6 +26,10 @@ extern int remap_oldmem_pfn_range(struct vm_area_struct > *vma, > > extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, > unsigned long, int); > +extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, > + size_t csize, unsigned long offset, > + int userbuf); > +
Here, it may be have a compile error. Links: https://lore.kernel.org/patchwork/patch/993337/ kbuild test robot Sept. 29, 2018, 6:25 p.m. UTC | #1 The correct patch is this one, you might refer to "Re: [PATCH v9 4/4] kdump/vmcore:support encrypted old memory with SME enabled" or this links. Links: https://lore.kernel.org/patchwork/patch/993538/#1177439 lijiang Sept. 30, 2018, 8:37 a.m. UTC | #2 diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h index 3e4ba9d753c8..84d8ddcb818e 100644 --- a/include/linux/crash_dump.h +++ b/include/linux/crash_dump.h @@ -26,6 +26,19 @@ extern int remap_oldmem_pfn_range(struct vm_area_struct *vma, extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, unsigned long, int); +#if defined(CONFIG_AMD_MEM_ENCRYPT) || defined(CONFIG_X86_64) +extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, + size_t csize, unsigned long offset, + int userbuf); +#else +static inline +ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize, + unsigned long offset, int userbuf) +{ + return 0; +} +#endif + Thanks. Lianbo > void vmcore_cleanup(void); > > /* Architecture code defines this if there are other possible ELF >
