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authorJoerg Roedel <joerg.roedel@amd.com>2009-03-16 11:51:55 -0400
committerJoerg Roedel <joerg.roedel@amd.com>2009-03-17 07:56:48 -0400
commit2e34bde18576a02c897ae6b699ea26301d92be1b (patch)
tree301278f1af66dd5be296814e19af2f6190e27634
parent6c132d1bcdc716e898b4092bb1abc696505c37e7 (diff)
dma-debug: add checks for kernel text and rodata
Impact: get notified if a device dma maps illegal areas This patch adds a check to print a warning message when a device driver tries to map a memory area from the kernel text segment or rodata. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
-rw-r--r--lib/dma-debug.c26
1 files changed, 25 insertions, 1 deletions
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index dba02f138bd3..6022eb4a0cd0 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -29,6 +29,8 @@
29#include <linux/list.h> 29#include <linux/list.h>
30#include <linux/slab.h> 30#include <linux/slab.h>
31 31
32#include <asm/sections.h>
33
32#define HASH_SIZE 1024ULL 34#define HASH_SIZE 1024ULL
33#define HASH_FN_SHIFT 13 35#define HASH_FN_SHIFT 13
34#define HASH_FN_MASK (HASH_SIZE - 1) 36#define HASH_FN_MASK (HASH_SIZE - 1)
@@ -549,6 +551,24 @@ static void check_for_stack(struct device *dev, void *addr)
549 "stack [addr=%p]\n", addr); 551 "stack [addr=%p]\n", addr);
550} 552}
551 553
554static inline bool overlap(void *addr, u64 size, void *start, void *end)
555{
556 void *addr2 = (char *)addr + size;
557
558 return ((addr >= start && addr < end) ||
559 (addr2 >= start && addr2 < end) ||
560 ((addr < start) && (addr2 >= end)));
561}
562
563static void check_for_illegal_area(struct device *dev, void *addr, u64 size)
564{
565 if (overlap(addr, size, _text, _etext) ||
566 overlap(addr, size, __start_rodata, __end_rodata))
567 err_printk(dev, NULL, "DMA-API: device driver maps "
568 "memory from kernel text or rodata "
569 "[addr=%p] [size=%llu]\n", addr, size);
570}
571
552static void check_sync(struct device *dev, dma_addr_t addr, 572static void check_sync(struct device *dev, dma_addr_t addr,
553 u64 size, u64 offset, int direction, bool to_cpu) 573 u64 size, u64 offset, int direction, bool to_cpu)
554{ 574{
@@ -645,8 +665,11 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
645 entry->direction = direction; 665 entry->direction = direction;
646 666
647 if (map_single) { 667 if (map_single) {
668 void *addr = ((char *)page_address(page)) + offset;
669
648 entry->type = dma_debug_single; 670 entry->type = dma_debug_single;
649 check_for_stack(dev, page_address(page) + offset); 671 check_for_stack(dev, addr);
672 check_for_illegal_area(dev, addr, size);
650 } 673 }
651 674
652 add_dma_entry(entry); 675 add_dma_entry(entry);
@@ -699,6 +722,7 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
699 entry->sg_mapped_ents = mapped_ents; 722 entry->sg_mapped_ents = mapped_ents;
700 723
701 check_for_stack(dev, sg_virt(s)); 724 check_for_stack(dev, sg_virt(s));
725 check_for_illegal_area(dev, sg_virt(s), s->length);
702 726
703 add_dma_entry(entry); 727 add_dma_entry(entry);
704 } 728 }