Messages in this thread Patch in this message | | | From | Baoquan He <> | Subject | [PATCH v2 5/9] add mem_min_overlap to find the first avoid region within a memory region | Date | Mon, 2 Mar 2015 22:58:26 +0800 |
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Given a memory region mem_min_overlap will iterate all avoid region to find the first one which overlap with it. This function will be used later.
Signed-off-by: Baoquan He <bhe@redhat.com> --- arch/x86/boot/compressed/aslr.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)
diff --git a/arch/x86/boot/compressed/aslr.c b/arch/x86/boot/compressed/aslr.c index 26610a2..ded3959 100644 --- a/arch/x86/boot/compressed/aslr.c +++ b/arch/x86/boot/compressed/aslr.c @@ -213,6 +213,38 @@ static bool mem_avoid_overlap(struct mem_vector *img) return false; } +static unsigned long mem_min_overlap(struct mem_vector *img, struct mem_vector *out) +{ + int i; + struct setup_data *ptr; + unsigned long min = img->start + img->size; + + for (i = 0; i < MEM_AVOID_MAX; i++) { + if (mem_overlaps(img, &mem_avoid[i]) && (mem_avoid[i].start < min) ) { + *out = mem_avoid[i]; + min = mem_avoid[i].start; + } + } + + /* Check all entries in the setup_data linked list. */ + ptr = (struct setup_data *)(unsigned long)real_mode->hdr.setup_data; + while (ptr) { + struct mem_vector avoid; + + avoid.start = (unsigned long)ptr; + avoid.size = sizeof(*ptr) + ptr->len; + + if (mem_overlaps(img, &avoid) && (avoid.start < min) ) { + *out = avoid; + min = avoid.start; + } + + ptr = (struct setup_data *)(unsigned long)ptr->next; + } + + return min; +} + static unsigned long slots[CONFIG_RANDOMIZE_BASE_MAX_OFFSET / CONFIG_PHYSICAL_ALIGN]; -- 1.9.3
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