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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: Kees Cook <keescook@chromium.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Kees Cook 2018-06-29 11:51:07 -07:00 committed by Vinod Koul
parent ce397d215c
commit e6a785116d
1 changed files with 13 additions and 2 deletions
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15
drivers/dma/ste_dma40.c
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@ -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: