diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 6f074e112c1e..62e0227d390e 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -566,9 +566,8 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map, int crash_exclude_mem_range(struct crash_mem *mem, unsigned long long mstart, unsigned long long mend) { - int i, j; + int i; unsigned long long start, end, p_start, p_end; - struct range temp_range = {0, 0}; for (i = 0; i < mem->nr_ranges; i++) { start = mem->ranges[i].start; @@ -576,72 +575,51 @@ int crash_exclude_mem_range(struct crash_mem *mem, p_start = mstart; p_end = mend; - if (mstart > end || mend < start) + if (p_start > end) continue; + /* + * Because the memory ranges in mem->ranges are stored in + * ascending order, when we detect `p_end < start`, we can + * immediately exit the for loop, as the subsequent memory + * ranges will definitely be outside the range we are looking + * for. + */ + if (p_end < start) + break; + /* Truncate any area outside of range */ - if (mstart < start) + if (p_start < start) p_start = start; - if (mend > end) + if (p_end > end) p_end = end; /* Found completely overlapping range */ if (p_start == start && p_end == end) { - mem->ranges[i].start = 0; - mem->ranges[i].end = 0; - if (i < mem->nr_ranges - 1) { - /* Shift rest of the ranges to left */ - for (j = i; j < mem->nr_ranges - 1; j++) { - mem->ranges[j].start = - mem->ranges[j+1].start; - mem->ranges[j].end = - mem->ranges[j+1].end; - } - - /* - * Continue to check if there are another overlapping ranges - * from the current position because of shifting the above - * mem ranges. - */ - i--; - mem->nr_ranges--; - continue; - } + memmove(&mem->ranges[i], &mem->ranges[i + 1], + (mem->nr_ranges - (i + 1)) * sizeof(mem->ranges[i])); + i--; mem->nr_ranges--; - return 0; - } - - if (p_start > start && p_end < end) { + } else if (p_start > start && p_end < end) { /* Split original range */ + if (mem->nr_ranges >= mem->max_nr_ranges) + return -ENOMEM; + + memmove(&mem->ranges[i + 2], &mem->ranges[i + 1], + (mem->nr_ranges - (i + 1)) * sizeof(mem->ranges[i])); + mem->ranges[i].end = p_start - 1; - temp_range.start = p_end + 1; - temp_range.end = end; + mem->ranges[i + 1].start = p_end + 1; + mem->ranges[i + 1].end = end; + + i++; + mem->nr_ranges++; } else if (p_start != start) mem->ranges[i].end = p_start - 1; else mem->ranges[i].start = p_end + 1; - break; } - /* If a split happened, add the split to array */ - if (!temp_range.end) - return 0; - - /* Split happened */ - if (i == mem->max_nr_ranges - 1) - return -ENOMEM; - - /* Location where new range should go */ - j = i + 1; - if (j < mem->nr_ranges) { - /* Move over all ranges one slot towards the end */ - for (i = mem->nr_ranges - 1; i >= j; i--) - mem->ranges[i + 1] = mem->ranges[i]; - } - - mem->ranges[j].start = temp_range.start; - mem->ranges[j].end = temp_range.end; - mem->nr_ranges++; return 0; }