Commit Graph

6 Commits

Author SHA1 Message Date
Stephen Boyd
169a58ad82 module/decompress: Support zstd in-kernel decompression
Add support for zstd compressed modules to the in-kernel decompression
code. This allows zstd compressed modules to be decompressed by the
kernel, similar to the existing support for gzip and xz compressed
modules.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Piotr Gorski <lucjan.lucjanov@gmail.com>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Piotr Gorski <lucjan.lucjanov@gmail.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-12-07 12:05:05 -08:00
Miaoqian Lin
45af1d7aae module: Fix NULL vs IS_ERR checking for module_get_next_page
The module_get_next_page() function return error pointers on error
instead of NULL.
Use IS_ERR() to check the return value to fix this.

Fixes: b1ae6dc41e ("module: add in-kernel support for decompressing")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-11-11 10:19:52 -08:00
David Disseldorp
77d6354bd4 module/decompress: generate sysfs string at compile time
compression_show() before (with noinline):
   0xffffffff810b5ff0 <+0>:     mov    %rdx,%rdi
   0xffffffff810b5ff3 <+3>:     mov    $0xffffffff81b55629,%rsi
   0xffffffff810b5ffa <+10>:    mov    $0xffffffff81b0cde2,%rdx
   0xffffffff810b6001 <+17>:    call   0xffffffff811b8fd0 <sysfs_emit>
   0xffffffff810b6006 <+22>:    cltq
   0xffffffff810b6008 <+24>:    ret

After:
   0xffffffff810b5ff0 <+0>:     mov    $0xffffffff81b0cde2,%rsi
   0xffffffff810b5ff7 <+7>:     mov    %rdx,%rdi
   0xffffffff810b5ffa <+10>:    call   0xffffffff811b8fd0 <sysfs_emit>
   0xffffffff810b5fff <+15>:    cltq
   0xffffffff810b6001 <+17>:    ret

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-09-08 17:00:43 -07:00
Fabio M. De Francesco
554694ba12 module: Replace kmap() with kmap_local_page()
kmap() is being deprecated in favor of kmap_local_page().

Two main problems with kmap(): (1) It comes with an overhead as mapping
space is restricted and protected by a global lock for synchronization and
(2) it also requires global TLB invalidation when the kmap’s pool wraps
and it might block when the mapping space is fully utilized until a slot
becomes available.

With kmap_local_page() the mappings are per thread, CPU local, can take
page faults, and can be called from any context (including interrupts).
Tasks can be preempted and, when scheduled to run again, the kernel
virtual addresses are restored and still valid.

kmap_local_page() is faster than kmap() in kernels with HIGHMEM enabled.

Since the use of kmap_local_page() in module_gzip_decompress() and in
module_xz_decompress() is safe (i.e., it does not break the strict rules
of use), it should be preferred over kmap().

Therefore, replace kmap() with kmap_local_page().

Tested on a QEMU/KVM x86_32 VM with 4GB RAM, booting kernels with
HIGHMEM64GB enabled. Modules compressed with XZ or GZIP decompress
properly.

Cc: Matthew Wilcox <willy@infradead.com>
Suggested-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-07-20 14:27:46 -07:00
Aaron Tomlin
5aff4dfdb4 module: Make internal.h and decompress.c more compliant
This patch will address the following warning and style violations
generated by ./scripts/checkpatch.pl in strict mode:

  WARNING: Use #include <linux/module.h> instead of <asm/module.h>
  #10: FILE: kernel/module/internal.h:10:
  +#include <asm/module.h>

  CHECK: spaces preferred around that '-' (ctx:VxV)
  #18: FILE: kernel/module/internal.h:18:
  +#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))

  CHECK: Please use a blank line after function/struct/union/enum declarations
  #69: FILE: kernel/module/internal.h:69:
  +}
  +static inline void module_decompress_cleanup(struct load_info *info)
						   ^
  CHECK: extern prototypes should be avoided in .h files
  #84: FILE: kernel/module/internal.h:84:
  +extern int mod_verify_sig(const void *mod, struct load_info *info);

  WARNING: Missing a blank line after declarations
  #116: FILE: kernel/module/decompress.c:116:
  +               struct page *page = module_get_next_page(info);
  +               if (!page) {

  WARNING: Missing a blank line after declarations
  #174: FILE: kernel/module/decompress.c:174:
  +               struct page *page = module_get_next_page(info);
  +               if (!page) {

  CHECK: Please use a blank line after function/struct/union/enum declarations
  #258: FILE: kernel/module/decompress.c:258:
  +}
  +static struct kobj_attribute module_compression_attr = __ATTR_RO(compression);

Note: Fortunately, the multiple-include optimisation found in
include/linux/module.h will prevent duplication/or inclusion more than
once.

Fixes: f314dfea16 ("modsign: log module name in the event of an error")
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-05 08:42:35 -07:00
Aaron Tomlin
cfc1d27789 module: Move all into module/
No functional changes.

This patch moves all module related code into a separate directory,
modifies each file name and creates a new Makefile. Note: this effort
is in preparation to refactor core module code.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-04-04 12:57:54 -07:00