diff options
| author | Jiri Olsa <jolsa@kernel.org> | 2016-09-08 09:57:07 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-09-20 13:32:49 -0700 |
| commit | f5beeb1851ea6f8cfcf2657f26cb24c0582b4945 (patch) | |
| tree | f619d5d6686ec8e43fe5f234c52f551f1febacad /fs | |
| parent | d2ffb0103aaefa9b169da042cf39ce27bfb6cdbb (diff) | |
| download | linux-f5beeb1851ea6f8cfcf2657f26cb24c0582b4945.tar.gz | |
fs/proc/kcore.c: Make bounce buffer global for read
Next patch adds bounce buffer for ktext area, so it's convenient to have single bounce buffer for both vmalloc/module and ktext cases. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/proc/kcore.c | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c index a939f5ed7f89..bd3ac9dca252 100644 --- a/fs/proc/kcore.c +++ b/fs/proc/kcore.c @@ -430,6 +430,7 @@ static void elf_kcore_store_hdr(char *bufp, int nphdr, int dataoff) static ssize_t read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) { + char *buf = file->private_data; ssize_t acc = 0; size_t size, tsz; size_t elf_buflen; @@ -500,18 +501,10 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) if (clear_user(buffer, tsz)) return -EFAULT; } else if (is_vmalloc_or_module_addr((void *)start)) { - char * elf_buf; - - elf_buf = kzalloc(tsz, GFP_KERNEL); - if (!elf_buf) - return -ENOMEM; - vread(elf_buf, (char *)start, tsz); + vread(buf, (char *)start, tsz); /* we have to zero-fill user buffer even if no read */ - if (copy_to_user(buffer, elf_buf, tsz)) { - kfree(elf_buf); + if (copy_to_user(buffer, buf, tsz)) return -EFAULT; - } - kfree(elf_buf); } else { if (kern_addr_valid(start)) { unsigned long n; @@ -549,6 +542,11 @@ static int open_kcore(struct inode *inode, struct file *filp) { if (!capable(CAP_SYS_RAWIO)) return -EPERM; + + filp->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!filp->private_data) + return -ENOMEM; + if (kcore_need_update) kcore_update_ram(); if (i_size_read(inode) != proc_root_kcore->size) { @@ -559,10 +557,16 @@ static int open_kcore(struct inode *inode, struct file *filp) return 0; } +static int release_kcore(struct inode *inode, struct file *file) +{ + kfree(file->private_data); + return 0; +} static const struct file_operations proc_kcore_operations = { .read = read_kcore, .open = open_kcore, + .release = release_kcore, .llseek = default_llseek, }; |