diff options
author | Alexander Gordeev <agordeev@linux.ibm.com> | 2022-01-29 11:24:50 +0300 |
---|---|---|
committer | Vasily Gorbik <gor@linux.ibm.com> | 2022-02-10 00:56:04 +0300 |
commit | 303fd988ed644c7daa260410f3ac99266573557d (patch) | |
tree | e93519a8541e4300b55f52a3c320beac2f7214a6 /arch/s390/kernel/crash_dump.c | |
parent | dc306186a130c6d9feb0aabc1c71b8ed1674a3bf (diff) | |
download | linux-303fd988ed644c7daa260410f3ac99266573557d.tar.xz |
s390/maccess: fix semantics of memcpy_real() and its callers
There is a confusion with regard to the source address of
memcpy_real() and calling functions. While the declared
type for a source assumes a virtual address, in fact it
always called with physical address of the source.
This confusion led to bugs in copy_oldmem_kernel() and
copy_oldmem_user() functions, where __pa() macro applied
mistakenly to physical addresses. It does not lead to a
real issue, since virtual and physical addresses are
currently the same.
Fix both the bugs and memcpy_real() prototype by making
type of source address consistent to the function name
and the way it actually used.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel/crash_dump.c')
-rw-r--r-- | arch/s390/kernel/crash_dump.c | 58 |
1 files changed, 28 insertions, 30 deletions
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c index a62bee83a88b..69819b765250 100644 --- a/arch/s390/kernel/crash_dump.c +++ b/arch/s390/kernel/crash_dump.c @@ -132,28 +132,27 @@ static inline void *load_real_addr(void *addr) /* * Copy memory of the old, dumped system to a kernel space virtual address */ -int copy_oldmem_kernel(void *dst, void *src, size_t count) +int copy_oldmem_kernel(void *dst, unsigned long src, size_t count) { - unsigned long from, len; + unsigned long len; void *ra; int rc; while (count) { - from = __pa(src); - if (!oldmem_data.start && from < sclp.hsa_size) { + if (!oldmem_data.start && src < sclp.hsa_size) { /* Copy from zfcp/nvme dump HSA area */ - len = min(count, sclp.hsa_size - from); - rc = memcpy_hsa_kernel(dst, from, len); + len = min(count, sclp.hsa_size - src); + rc = memcpy_hsa_kernel(dst, src, len); if (rc) return rc; } else { /* Check for swapped kdump oldmem areas */ - if (oldmem_data.start && from - oldmem_data.start < oldmem_data.size) { - from -= oldmem_data.start; - len = min(count, oldmem_data.size - from); - } else if (oldmem_data.start && from < oldmem_data.size) { - len = min(count, oldmem_data.size - from); - from += oldmem_data.start; + if (oldmem_data.start && src - oldmem_data.start < oldmem_data.size) { + src -= oldmem_data.start; + len = min(count, oldmem_data.size - src); + } else if (oldmem_data.start && src < oldmem_data.size) { + len = min(count, oldmem_data.size - src); + src += oldmem_data.start; } else { len = count; } @@ -163,7 +162,7 @@ int copy_oldmem_kernel(void *dst, void *src, size_t count) } else { ra = dst; } - if (memcpy_real(ra, (void *) from, len)) + if (memcpy_real(ra, src, len)) return -EFAULT; } dst += len; @@ -176,31 +175,30 @@ int copy_oldmem_kernel(void *dst, void *src, size_t count) /* * Copy memory of the old, dumped system to a user space virtual address */ -static int copy_oldmem_user(void __user *dst, void *src, size_t count) +static int copy_oldmem_user(void __user *dst, unsigned long src, size_t count) { - unsigned long from, len; + unsigned long len; int rc; while (count) { - from = __pa(src); - if (!oldmem_data.start && from < sclp.hsa_size) { + if (!oldmem_data.start && src < sclp.hsa_size) { /* Copy from zfcp/nvme dump HSA area */ - len = min(count, sclp.hsa_size - from); - rc = memcpy_hsa_user(dst, from, len); + len = min(count, sclp.hsa_size - src); + rc = memcpy_hsa_user(dst, src, len); if (rc) return rc; } else { /* Check for swapped kdump oldmem areas */ - if (oldmem_data.start && from - oldmem_data.start < oldmem_data.size) { - from -= oldmem_data.start; - len = min(count, oldmem_data.size - from); - } else if (oldmem_data.start && from < oldmem_data.size) { - len = min(count, oldmem_data.size - from); - from += oldmem_data.start; + if (oldmem_data.start && src - oldmem_data.start < oldmem_data.size) { + src -= oldmem_data.start; + len = min(count, oldmem_data.size - src); + } else if (oldmem_data.start && src < oldmem_data.size) { + len = min(count, oldmem_data.size - src); + src += oldmem_data.start; } else { len = count; } - rc = copy_to_user_real(dst, (void *) from, count); + rc = copy_to_user_real(dst, src, count); if (rc) return rc; } @@ -217,12 +215,12 @@ static int copy_oldmem_user(void __user *dst, void *src, size_t count) ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, unsigned long offset, int userbuf) { - void *src; + unsigned long src; int rc; if (!csize) return 0; - src = (void *) (pfn << PAGE_SHIFT) + offset; + src = pfn_to_phys(pfn) + offset; if (userbuf) rc = copy_oldmem_user((void __force __user *) buf, src, csize); else @@ -429,10 +427,10 @@ static void *nt_prpsinfo(void *ptr) static void *get_vmcoreinfo_old(unsigned long *size) { char nt_name[11], *vmcoreinfo; + unsigned long addr; Elf64_Nhdr note; - void *addr; - if (copy_oldmem_kernel(&addr, (void *)__LC_VMCORE_INFO, sizeof(addr))) + if (copy_oldmem_kernel(&addr, __LC_VMCORE_INFO, sizeof(addr))) return NULL; memset(nt_name, 0, sizeof(nt_name)); if (copy_oldmem_kernel(¬e, addr, sizeof(note))) |