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module/decompress: use vmalloc() for zstd decompression workspace

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Using kmalloc() to allocate the decompression workspace for zstd may
trigger the following warning when large modules are loaded (i.e., xfs):

[    2.961884] WARNING: CPU: 1 PID: 254 at mm/page_alloc.c:4453 __alloc_pages+0x2c3/0x350
...
[    2.989033] Call Trace:
[    2.989841]  <TASK>
[    2.990614]  ? show_regs+0x6d/0x80
[    2.991573]  ? __warn+0x89/0x160
[    2.992485]  ? __alloc_pages+0x2c3/0x350
[    2.993520]  ? report_bug+0x17e/0x1b0
[    2.994506]  ? handle_bug+0x51/0xa0
[    2.995474]  ? exc_invalid_op+0x18/0x80
[    2.996469]  ? asm_exc_invalid_op+0x1b/0x20
[    2.997530]  ? module_zstd_decompress+0xdc/0x2a0
[    2.998665]  ? __alloc_pages+0x2c3/0x350
[    2.999695]  ? module_zstd_decompress+0xdc/0x2a0
[    3.000821]  __kmalloc_large_node+0x7a/0x150
[    3.001920]  __kmalloc+0xdb/0x170
[    3.002824]  module_zstd_decompress+0xdc/0x2a0
[    3.003857]  module_decompress+0x37/0xc0
[    3.004688]  init_module_from_file+0xd0/0x100
[    3.005668]  idempotent_init_module+0x11c/0x2b0
[    3.006632]  __x64_sys_finit_module+0x64/0xd0
[    3.007568]  do_syscall_64+0x59/0x90
[    3.008373]  ? ksys_read+0x73/0x100
[    3.009395]  ? exit_to_user_mode_prepare+0x30/0xb0
[    3.010531]  ? syscall_exit_to_user_mode+0x37/0x60
[    3.011662]  ? do_syscall_64+0x68/0x90
[    3.012511]  ? do_syscall_64+0x68/0x90
[    3.013364]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8

However, continuous physical memory does not seem to be required in
module_zstd_decompress(), so use vmalloc() instead, to prevent the
warning and avoid potential failures at loading compressed modules.

Fixes: 169a58ad82 ("module/decompress: Support zstd in-kernel decompression")
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
This commit is contained in:
Andrea Righi 2023-08-29 14:05:08 +02:00 committed by Luis Chamberlain
parent 33c24bee4b
commit a419beac4a
1 changed files with 2 additions and 2 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

4
kernel/module/decompress.c
View file

@ -241,7 +241,7 @@ static ssize_t module_zstd_decompress(struct load_info *info,
}
wksp_size = zstd_dstream_workspace_bound(header.windowSize);
wksp = kmalloc(wksp_size, GFP_KERNEL);
wksp = vmalloc(wksp_size);
if (!wksp) {
retval = -ENOMEM;
goto out;
@ -284,7 +284,7 @@ static ssize_t module_zstd_decompress(struct load_info *info,
retval = new_size;
out:
kfree(wksp);
vfree(wksp);
return retval;
}
#else