`strncpy` is deprecated for use on NUL-terminated destination strings [1]. We should prefer more robust and less ambiguous string interfaces. A suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on the destination buffer without unnecessarily NUL-padding. `ctx` is zero allocated and as such strncpy's NUL-padding behavior was strictly a performance hit which is now resolved. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@xxxxxxxxxxxxxxx Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx> --- Changes in v2: - drop the `... - 1` (thanks Kees) - Link to v1: https://lore.kernel.org/r/20230914-strncpy-drivers-gpu-drm-i915-gem-selftests-mock_context-c-v1-1-c3f92df942e0@xxxxxxxxxx --- drivers/gpu/drm/i915/gem/selftests/mock_context.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gem/selftests/mock_context.c b/drivers/gpu/drm/i915/gem/selftests/mock_context.c index 8ac6726ec16b..e199d7dbb876 100644 --- a/drivers/gpu/drm/i915/gem/selftests/mock_context.c +++ b/drivers/gpu/drm/i915/gem/selftests/mock_context.c @@ -36,7 +36,7 @@ mock_context(struct drm_i915_private *i915, if (name) { struct i915_ppgtt *ppgtt; - strncpy(ctx->name, name, sizeof(ctx->name) - 1); + strscpy(ctx->name, name, sizeof(ctx->name)); ppgtt = mock_ppgtt(i915, name); if (!ppgtt) --- base-commit: 3669558bdf354cd352be955ef2764cde6a9bf5ec change-id: 20230914-strncpy-drivers-gpu-drm-i915-gem-selftests-mock_context-c-980c8ecc9142 Best regards, -- Justin Stitt <justinstitt@xxxxxxxxxx>
