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Commit e6a78511 authored by Kees Cook's avatar Kees Cook Committed by Vinod Koul
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dmaengine: ste_dma40: Remove VLA usage 

In the quest to remove all stack VLA usage from the kernel[1], this
switches to using a pre-allocated scratch register space, set up with
all other other allocations.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com



Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent ce397d21

drivers/dma/ste_dma40.c

+13 −2
Original line number Diff line number Diff line
@@ -555,6 +555,7 @@ struct d40_gen_dmac { 
 * @reg_val_backup_v4: Backup of registers that only exits on dma40 v3 and

 * later

 * @reg_val_backup_chan: Backup data for standard channel parameter registers.

 * @regs_interrupt: Scratch space for registers during interrupt.

 * @gcc_pwr_off_mask: Mask to maintain the channels that can be turned off.

 * @gen_dmac: the struct for generic registers values to represent u8500/8540

 * DMA controller
@@ -592,6 +593,7 @@ struct d40_base { 
	u32				  reg_val_backup[BACKUP_REGS_SZ];

	u32				  reg_val_backup_v4[BACKUP_REGS_SZ_MAX];

	u32				 *reg_val_backup_chan;

	u32				 *regs_interrupt;

	u16				  gcc_pwr_off_mask;

	struct d40_gen_dmac		  gen_dmac;

};
@@ -1637,7 +1639,7 @@ static irqreturn_t d40_handle_interrupt(int irq, void *data) 
	struct d40_chan *d40c;

	unsigned long flags;

	struct d40_base *base = data;

	u32 regs[base->gen_dmac.il_size];

	u32 *regs = base->regs_interrupt;

	struct d40_interrupt_lookup *il = base->gen_dmac.il;

	u32 il_size = base->gen_dmac.il_size;
@@ -3258,13 +3260,22 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev) 
	if (!base->lcla_pool.alloc_map)

		goto free_backup_chan;



	base->regs_interrupt = kmalloc_array(base->gen_dmac.il_size,

					     sizeof(*base->regs_interrupt),

					     GFP_KERNEL);

	if (!base->regs_interrupt)

		goto free_map;



	base->desc_slab = kmem_cache_create(D40_NAME, sizeof(struct d40_desc),

					    0, SLAB_HWCACHE_ALIGN,

					    NULL);

	if (base->desc_slab == NULL)

		goto free_map;

		goto free_regs;





	return base;

 free_regs:

	kfree(base->regs_interrupt);

 free_map:

	kfree(base->lcla_pool.alloc_map);

 free_backup_chan: