| Message ID | 20230830155820.138178-1-andrea.righi@canonical.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | module/decompress: use vmalloc() for gzip decompression workspace | expand |
On Wed, Aug 30, 2023 at 05:58:20PM +0200, Andrea Righi wrote: > Use a similar approach as commit a419beac4a07 ("module/decompress: use > vmalloc() for zstd decompression workspace") and replace kmalloc() with > vmalloc() also for the gzip module decompression workspace. > > In this case the workspace is represented by struct inflate_workspace > that can be fairly large for kmalloc() and it can potentially lead to > allocation errors on certain systems: > > $ pahole inflate_workspace > struct inflate_workspace { > struct inflate_state inflate_state; /* 0 9544 */ > /* --- cacheline 149 boundary (9536 bytes) was 8 bytes ago --- */ > unsigned char working_window[32768]; /* 9544 32768 */ > > /* size: 42312, cachelines: 662, members: 2 */ > /* last cacheline: 8 bytes */ > }; > > Considering that there is no need to use continuous physical memory, > simply switch to vmalloc() to provide a more reliable in-kernel module > decompression. > > Fixes: b1ae6dc41eaa ("module: add in-kernel support for decompressing") > Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Applied, and pushed, thanks! Luis
diff --git a/kernel/module/decompress.c b/kernel/module/decompress.c index 87440f714c0c..4156d59be440 100644 --- 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 = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); + s.workspace = vmalloc(zlib_inflate_workspacesize()); 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: - kfree(s.workspace); + vfree(s.workspace); return retval; } #elif defined(CONFIG_MODULE_COMPRESS_XZ)
Use a similar approach as commit a419beac4a07 ("module/decompress: use vmalloc() for zstd decompression workspace") and replace kmalloc() with vmalloc() also for the gzip module decompression workspace. In this case the workspace is represented by struct inflate_workspace that can be fairly large for kmalloc() and it can potentially lead to allocation errors on certain systems: $ pahole inflate_workspace struct inflate_workspace { struct inflate_state inflate_state; /* 0 9544 */ /* --- cacheline 149 boundary (9536 bytes) was 8 bytes ago --- */ unsigned char working_window[32768]; /* 9544 32768 */ /* size: 42312, cachelines: 662, members: 2 */ /* last cacheline: 8 bytes */ }; Considering that there is no need to use continuous physical memory, simply switch to vmalloc() to provide a more reliable in-kernel module decompression. Fixes: b1ae6dc41eaa ("module: add in-kernel support for decompressing") Signed-off-by: Andrea Righi <andrea.righi@canonical.com> --- kernel/module/decompress.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)