[PATCH 02/12] drm/panic: Make allocation of zlib workspace more robust
Thomas Zimmermann <[email protected]>
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| Message-ID | <[email protected]> |
Test the zlib workspace size to not have a negative value. This would be a driver bug. Also touch allocated memory so that the pages are available upon a panic. Signed-off-by: Thomas Zimmermann <[email protected]> --- drivers/gpu/drm/drm_panic.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c index 0685f7d8dba2..705b72bf0d83 100644 --- a/drivers/gpu/drm/drm_panic.c +++ b/drivers/gpu/drm/drm_panic.c @@ -634,13 +634,19 @@ static struct z_stream_s stream; static void __init drm_panic_qr_init(void) { + int wssize; + + wssize = zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL); + if (WARN_ON_ONCE(wssize < 0)) + return; /* best-effort allocation; can be NULL */ - stream.workspace = kmalloc(zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL), - GFP_KERNEL); + stream.workspace = kmalloc(wssize, GFP_KERNEL); /* touch memory so that pages are there in the case of a panic */ memset(qrbuf1, 0, sizeof(qrbuf1)); memset(qrbuf2, 0, sizeof(qrbuf2)); + if (stream.workspace) + memset(stream.workspace, 0, wssize); } static void drm_panic_qr_exit(void) -- 2.55.0