module/decompress: use kvmalloc() consistently

We consistently switched from kmalloc() to vmalloc() in module
decompression to prevent potential memory allocation failures with large
modules, however vmalloc() is not as memory-efficient and fast as
kmalloc().

Since we don't know in general the size of the workspace required by the
decompression algorithm, it is more reasonable to use kvmalloc()
consistently, also considering that we don't have special memory
requirements here.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/module/decompress.c b/kernel/module/decompress.c
index 4156d59be44081219c290c2311cdcd2aad74f1f9..474e68f0f0634913625003bbdf6610b23fb7ff15 100644 (file)
--- a/kernel/module/decompress.c
+++ b/kernel/module/decompress.c
@@ -100,7 +100,7 @@ static ssize_t module_gzip_decompress(struct load_info *info,
        s.next_in = buf + gzip_hdr_len;
        s.avail_in = size - gzip_hdr_len;
 
-       s.workspace = vmalloc(zlib_inflate_workspacesize());
+       s.workspace = kvmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
        if (!s.workspace)
                return -ENOMEM;
 
@@ -138,7 +138,7 @@ static ssize_t module_gzip_decompress(struct load_info *info,
 out_inflate_end:
        zlib_inflateEnd(&s);
 out:
-       vfree(s.workspace);
+       kvfree(s.workspace);
        return retval;
 }
 #elif defined(CONFIG_MODULE_COMPRESS_XZ)
@@ -241,7 +241,7 @@ static ssize_t module_zstd_decompress(struct load_info *info,
        }
 
        wksp_size = zstd_dstream_workspace_bound(header.windowSize);
-       wksp = vmalloc(wksp_size);
+       wksp = kvmalloc(wksp_size, GFP_KERNEL);
        if (!wksp) {
                retval = -ENOMEM;
                goto out;
@@ -284,7 +284,7 @@ static ssize_t module_zstd_decompress(struct load_info *info,
        retval = new_size;
 
  out:
-       vfree(wksp);
+       kvfree(wksp);
        return retval;
 }
 #else