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path: root/fs/proc/vmcore.c
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Diffstat (limited to 'fs/proc/vmcore.c')
-rw-r--r--fs/proc/vmcore.c130
1 files changed, 56 insertions, 74 deletions
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 6f1b8ddc6f7a..4eaeb645e759 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -26,6 +26,7 @@
#include <linux/vmalloc.h>
#include <linux/pagemap.h>
#include <linux/uaccess.h>
+#include <linux/uio.h>
#include <linux/cc_platform.h>
#include <asm/io.h>
#include "internal.h"
@@ -128,9 +129,8 @@ static int open_vmcore(struct inode *inode, struct file *file)
}
/* Reads a page from the oldmem device from given offset. */
-ssize_t read_from_oldmem(char *buf, size_t count,
- u64 *ppos, int userbuf,
- bool encrypted)
+ssize_t read_from_oldmem(struct iov_iter *iter, size_t count,
+ u64 *ppos, bool encrypted)
{
unsigned long pfn, offset;
size_t nr_bytes;
@@ -152,29 +152,23 @@ ssize_t read_from_oldmem(char *buf, size_t count,
/* If pfn is not ram, return zeros for sparse dump files */
if (!pfn_is_ram(pfn)) {
- tmp = 0;
- if (!userbuf)
- memset(buf, 0, nr_bytes);
- else if (clear_user(buf, nr_bytes))
- tmp = -EFAULT;
+ tmp = iov_iter_zero(nr_bytes, iter);
} else {
if (encrypted)
- tmp = copy_oldmem_page_encrypted(pfn, buf,
+ tmp = copy_oldmem_page_encrypted(iter, pfn,
nr_bytes,
- offset,
- userbuf);
+ offset);
else
- tmp = copy_oldmem_page(pfn, buf, nr_bytes,
- offset, userbuf);
+ tmp = copy_oldmem_page(iter, pfn, nr_bytes,
+ offset);
}
- if (tmp < 0) {
+ if (tmp < nr_bytes) {
srcu_read_unlock(&vmcore_cb_srcu, idx);
- return tmp;
+ return -EFAULT;
}
*ppos += nr_bytes;
count -= nr_bytes;
- buf += nr_bytes;
read += nr_bytes;
++pfn;
offset = 0;
@@ -203,7 +197,12 @@ 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, false);
+ struct kvec kvec = { .iov_base = buf, .iov_len = count };
+ struct iov_iter iter;
+
+ iov_iter_kvec(&iter, READ, &kvec, 1, count);
+
+ return read_from_oldmem(&iter, count, ppos, false);
}
/*
@@ -211,7 +210,13 @@ 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, cc_platform_has(CC_ATTR_MEM_ENCRYPT));
+ struct kvec kvec = { .iov_base = buf, .iov_len = count };
+ struct iov_iter iter;
+
+ iov_iter_kvec(&iter, READ, &kvec, 1, count);
+
+ return read_from_oldmem(&iter, count, ppos,
+ cc_platform_has(CC_ATTR_MEM_ENCRYPT));
}
/*
@@ -228,29 +233,14 @@ int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma,
/*
* Architectures which support memory encryption override this.
*/
-ssize_t __weak
-copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize,
- unsigned long offset, int userbuf)
+ssize_t __weak copy_oldmem_page_encrypted(struct iov_iter *iter,
+ unsigned long pfn, size_t csize, unsigned long offset)
{
- return copy_oldmem_page(pfn, buf, csize, offset, userbuf);
-}
-
-/*
- * Copy to either kernel or user space
- */
-static int copy_to(void *target, void *src, size_t size, int userbuf)
-{
- if (userbuf) {
- if (copy_to_user((char __user *) target, src, size))
- return -EFAULT;
- } else {
- memcpy(target, src, size);
- }
- return 0;
+ return copy_oldmem_page(iter, pfn, csize, offset);
}
#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
-static int vmcoredd_copy_dumps(void *dst, u64 start, size_t size, int userbuf)
+static int vmcoredd_copy_dumps(struct iov_iter *iter, u64 start, size_t size)
{
struct vmcoredd_node *dump;
u64 offset = 0;
@@ -263,14 +253,13 @@ static int vmcoredd_copy_dumps(void *dst, u64 start, size_t size, int userbuf)
if (start < offset + dump->size) {
tsz = min(offset + (u64)dump->size - start, (u64)size);
buf = dump->buf + start - offset;
- if (copy_to(dst, buf, tsz, userbuf)) {
+ if (copy_to_iter(buf, tsz, iter) < tsz) {
ret = -EFAULT;
goto out_unlock;
}
size -= tsz;
start += tsz;
- dst += tsz;
/* Leave now if buffer filled already */
if (!size)
@@ -326,33 +315,28 @@ out_unlock:
/* Read from the ELF header and then the crash dump. On error, negative value is
* returned otherwise number of bytes read are returned.
*/
-static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos,
- int userbuf)
+static ssize_t __read_vmcore(struct iov_iter *iter, loff_t *fpos)
{
ssize_t acc = 0, tmp;
size_t tsz;
u64 start;
struct vmcore *m = NULL;
- if (buflen == 0 || *fpos >= vmcore_size)
+ if (!iov_iter_count(iter) || *fpos >= vmcore_size)
return 0;
- /* trim buflen to not go beyond EOF */
- if (buflen > vmcore_size - *fpos)
- buflen = vmcore_size - *fpos;
+ iov_iter_truncate(iter, vmcore_size - *fpos);
/* Read ELF core header */
if (*fpos < elfcorebuf_sz) {
- tsz = min(elfcorebuf_sz - (size_t)*fpos, buflen);
- if (copy_to(buffer, elfcorebuf + *fpos, tsz, userbuf))
+ tsz = min(elfcorebuf_sz - (size_t)*fpos, iov_iter_count(iter));
+ if (copy_to_iter(elfcorebuf + *fpos, tsz, iter) < tsz)
return -EFAULT;
- buflen -= tsz;
*fpos += tsz;
- buffer += tsz;
acc += tsz;
/* leave now if filled buffer already */
- if (buflen == 0)
+ if (!iov_iter_count(iter))
return acc;
}
@@ -373,35 +357,32 @@ static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos,
/* Read device dumps */
if (*fpos < elfcorebuf_sz + vmcoredd_orig_sz) {
tsz = min(elfcorebuf_sz + vmcoredd_orig_sz -
- (size_t)*fpos, buflen);
+ (size_t)*fpos, iov_iter_count(iter));
start = *fpos - elfcorebuf_sz;
- if (vmcoredd_copy_dumps(buffer, start, tsz, userbuf))
+ if (vmcoredd_copy_dumps(iter, start, tsz))
return -EFAULT;
- buflen -= tsz;
*fpos += tsz;
- buffer += tsz;
acc += tsz;
/* leave now if filled buffer already */
- if (!buflen)
+ if (!iov_iter_count(iter))
return acc;
}
#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
/* Read remaining elf notes */
- tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, buflen);
+ tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos,
+ iov_iter_count(iter));
kaddr = elfnotes_buf + *fpos - elfcorebuf_sz - vmcoredd_orig_sz;
- if (copy_to(buffer, kaddr, tsz, userbuf))
+ if (copy_to_iter(kaddr, tsz, iter) < tsz)
return -EFAULT;
- buflen -= tsz;
*fpos += tsz;
- buffer += tsz;
acc += tsz;
/* leave now if filled buffer already */
- if (buflen == 0)
+ if (!iov_iter_count(iter))
return acc;
}
@@ -409,19 +390,17 @@ static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos,
if (*fpos < m->offset + m->size) {
tsz = (size_t)min_t(unsigned long long,
m->offset + m->size - *fpos,
- buflen);
+ iov_iter_count(iter));
start = m->paddr + *fpos - m->offset;
- tmp = read_from_oldmem(buffer, tsz, &start,
- userbuf, cc_platform_has(CC_ATTR_MEM_ENCRYPT));
+ tmp = read_from_oldmem(iter, tsz, &start,
+ cc_platform_has(CC_ATTR_MEM_ENCRYPT));
if (tmp < 0)
return tmp;
- buflen -= tsz;
*fpos += tsz;
- buffer += tsz;
acc += tsz;
/* leave now if filled buffer already */
- if (buflen == 0)
+ if (!iov_iter_count(iter))
return acc;
}
}
@@ -429,15 +408,14 @@ static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos,
return acc;
}
-static ssize_t read_vmcore(struct file *file, char __user *buffer,
- size_t buflen, loff_t *fpos)
+static ssize_t read_vmcore(struct kiocb *iocb, struct iov_iter *iter)
{
- return __read_vmcore((__force char *) buffer, buflen, fpos, 1);
+ return __read_vmcore(iter, &iocb->ki_pos);
}
/*
* The vmcore fault handler uses the page cache and fills data using the
- * standard __vmcore_read() function.
+ * standard __read_vmcore() function.
*
* On s390 the fault handler is used for memory regions that can't be mapped
* directly with remap_pfn_range().
@@ -447,9 +425,10 @@ static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf)
#ifdef CONFIG_S390
struct address_space *mapping = vmf->vma->vm_file->f_mapping;
pgoff_t index = vmf->pgoff;
+ struct iov_iter iter;
+ struct kvec kvec;
struct page *page;
loff_t offset;
- char *buf;
int rc;
page = find_or_create_page(mapping, index, GFP_KERNEL);
@@ -457,8 +436,11 @@ static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf)
return VM_FAULT_OOM;
if (!PageUptodate(page)) {
offset = (loff_t) index << PAGE_SHIFT;
- buf = __va((page_to_pfn(page) << PAGE_SHIFT));
- rc = __read_vmcore(buf, PAGE_SIZE, &offset, 0);
+ kvec.iov_base = page_address(page);
+ kvec.iov_len = PAGE_SIZE;
+ iov_iter_kvec(&iter, READ, &kvec, 1, PAGE_SIZE);
+
+ rc = __read_vmcore(&iter, &offset);
if (rc < 0) {
unlock_page(page);
put_page(page);
@@ -708,7 +690,7 @@ static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
static const struct proc_ops vmcore_proc_ops = {
.proc_open = open_vmcore,
- .proc_read = read_vmcore,
+ .proc_read_iter = read_vmcore,
.proc_lseek = default_llseek,
.proc_mmap = mmap_vmcore,
};
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-27 22:52:13 +0300