6.12-stable review patch. If anyone has any objections, please let me know.
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From: Geert Uytterhoeven geert+renesas@glider.be
commit 22293c33738c14bb84b9d3e771bc37150e7cf8e7 upstream.
On RZ/Five, which is non-coherent, and uses CONFIG_DMA_GLOBAL_POOL=y:
Oops - store (or AMO) access fault [#1] CPU: 0 UID: 0 PID: 1 Comm: swapper Not tainted 6.12.0-rc1-00015-g8a6e02d0c00e #201 Hardware name: Renesas SMARC EVK based on r9a07g043f01 (DT) epc : __memset+0x60/0x100 ra : __dma_alloc_from_coherent+0x150/0x17a epc : ffffffff8062d2bc ra : ffffffff80053a94 sp : ffffffc60000ba20 gp : ffffffff812e9938 tp : ffffffd601920000 t0 : ffffffc6000d0000 t1 : 0000000000000000 t2 : ffffffffe9600000 s0 : ffffffc60000baa0 s1 : ffffffc6000d0000 a0 : ffffffc6000d0000 a1 : 0000000000000000 a2 : 0000000000001000 a3 : ffffffc6000d1000 a4 : 0000000000000000 a5 : 0000000000000000 a6 : ffffffd601adacc0 a7 : ffffffd601a841a8 s2 : ffffffd6018573c0 s3 : 0000000000001000 s4 : ffffffd6019541e0 s5 : 0000000200000022 s6 : ffffffd6018f8410 s7 : ffffffd6018573e8 s8 : 0000000000000001 s9 : 0000000000000001 s10: 0000000000000010 s11: 0000000000000000 t3 : 0000000000000000 t4 : ffffffffdefe62d1 t5 : 000000001cd6a3a9 t6 : ffffffd601b2aad6 status: 0000000200000120 badaddr: ffffffc6000d0000 cause: 0000000000000007 [<ffffffff8062d2bc>] __memset+0x60/0x100 [<ffffffff80053e1a>] dma_alloc_from_global_coherent+0x1c/0x28 [<ffffffff80053056>] dma_direct_alloc+0x98/0x112 [<ffffffff8005238c>] dma_alloc_attrs+0x78/0x86 [<ffffffff8035fdb4>] rz_dmac_probe+0x3f6/0x50a [<ffffffff803a0694>] platform_probe+0x4c/0x8a
If CONFIG_DMA_GLOBAL_POOL=y, the reserved_mem structure passed to rmem_dma_setup() is saved for later use, by saving the passed pointer. However, when dma_init_reserved_memory() is called later, the pointer has become stale, causing a crash.
E.g. in the RZ/Five case, the referenced memory now contains the reserved_mem structure for the "mmode_resv0@30000" node (with base 0x30000 and size 0x10000), instead of the correct "pma_resv0@58000000" node (with base 0x58000000 and size 0x8000000).
Fix this by saving the needed reserved_mem structure's contents instead.
Fixes: 8a6e02d0c00e7b62 ("of: reserved_mem: Restructure how the reserved memory regions are processed") Signed-off-by: Geert Uytterhoeven geert+renesas@glider.be Reviewed-by: Oreoluwa Babatunde quic_obabatun@quicinc.com Tested-by: Lad Prabhakar prabhakar.mahadev-lad.rj@bp.renesas.com Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/dma/coherent.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
--- a/kernel/dma/coherent.c +++ b/kernel/dma/coherent.c @@ -330,7 +330,8 @@ int dma_init_global_coherent(phys_addr_t #include <linux/of_reserved_mem.h>
#ifdef CONFIG_DMA_GLOBAL_POOL -static struct reserved_mem *dma_reserved_default_memory __initdata; +static phys_addr_t dma_reserved_default_memory_base __initdata; +static phys_addr_t dma_reserved_default_memory_size __initdata; #endif
static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) @@ -376,9 +377,10 @@ static int __init rmem_dma_setup(struct
#ifdef CONFIG_DMA_GLOBAL_POOL if (of_get_flat_dt_prop(node, "linux,dma-default", NULL)) { - WARN(dma_reserved_default_memory, + WARN(dma_reserved_default_memory_size, "Reserved memory: region for default DMA coherent area is redefined\n"); - dma_reserved_default_memory = rmem; + dma_reserved_default_memory_base = rmem->base; + dma_reserved_default_memory_size = rmem->size; } #endif
@@ -391,10 +393,10 @@ static int __init rmem_dma_setup(struct #ifdef CONFIG_DMA_GLOBAL_POOL static int __init dma_init_reserved_memory(void) { - if (!dma_reserved_default_memory) + if (!dma_reserved_default_memory_size) return -ENOMEM; - return dma_init_global_coherent(dma_reserved_default_memory->base, - dma_reserved_default_memory->size); + return dma_init_global_coherent(dma_reserved_default_memory_base, + dma_reserved_default_memory_size); } core_initcall(dma_init_reserved_memory); #endif /* CONFIG_DMA_GLOBAL_POOL */