devres: handle zero size in devm_kmalloc() (cad064f1) · Commits · 戴 / test

Make devm_kmalloc() behave similarly to non-managed kmalloc(): return ZERO_SIZE_PTR when requested size is 0. Update devm_kfree() to handle this case. Signed-off-by:

Bartosz Golaszewski <bgolaszewski@baylibre.com> Link: https://lore.kernel.org/r/20200629065008.27620-5-brgl@bgdev.pl Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/devres.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -819,6 +819,9 @@ void devm_kmalloc(struct device dev, size_t size, gfp_t gfp)
		{
		struct devres *dr;

		if (unlikely(!size))
		return ZERO_SIZE_PTR;

		/* use raw alloc_dr for kmalloc caller tracing */
		dr = alloc_dr(devm_kmalloc_release, size, gfp, dev_to_node(dev));
		if (unlikely(!dr))
		@@ -950,10 +953,10 @@ void devm_kfree(struct device dev, const void p)
		int rc;

		/*
		* Special case: pointer to a string in .rodata returned by
		* devm_kstrdup_const().
		* Special cases: pointer to a string in .rodata returned by
		* devm_kstrdup_const() or NULL/ZERO ptr.
		*/
		if (unlikely(is_kernel_rodata((unsigned long)p)))
		if (unlikely(is_kernel_rodata((unsigned long)p) \|\| ZERO_OR_NULL_PTR(p)))
		return;

		rc = devres_destroy(dev, devm_kmalloc_release,

Admin message