From 27811d8cabe56e0c3622251b049086f49face4ff Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Wed, 10 Feb 2010 01:20:07 -0800 Subject: x86: Move range related operation to one file We have almost the same code for mtrr cleanup and amd_bus checkup, and this code will also be used in replacing bootmem with early_res, so try to move them together and reuse it from different parts. Also rename update_range to subtract_range as that is what the function is actually doing. -v2: update comments as Christoph requested Signed-off-by: Yinghai Lu LKML-Reference: <1265793639-15071-4-git-send-email-yinghai@kernel.org> Signed-off-by: H. Peter Anvin --- kernel/Makefile | 2 +- kernel/range.c | 163 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 164 insertions(+), 1 deletion(-) create mode 100644 kernel/range.c (limited to 'kernel') diff --git a/kernel/Makefile b/kernel/Makefile index 864ff75d65f..ad47330ccf3 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -10,7 +10,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o \ kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \ hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \ notifier.o ksysfs.o pm_qos_params.o sched_clock.o cred.o \ - async.o + async.o range.o obj-y += groups.o ifdef CONFIG_FUNCTION_TRACER diff --git a/kernel/range.c b/kernel/range.c new file mode 100644 index 00000000000..71e0021281f --- /dev/null +++ b/kernel/range.c @@ -0,0 +1,163 @@ +/* + * Range add and subtract + */ +#include +#include +#include + +#include + +#ifndef ARRAY_SIZE +#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) +#endif + +int add_range(struct range *range, int az, int nr_range, u64 start, u64 end) +{ + if (start > end) + return nr_range; + + /* Out of slots: */ + if (nr_range >= az) + return nr_range; + + range[nr_range].start = start; + range[nr_range].end = end; + + nr_range++; + + return nr_range; +} + +int add_range_with_merge(struct range *range, int az, int nr_range, + u64 start, u64 end) +{ + int i; + + if (start > end) + return nr_range; + + /* Try to merge it with old one: */ + for (i = 0; i < nr_range; i++) { + u64 final_start, final_end; + u64 common_start, common_end; + + if (!range[i].end) + continue; + + common_start = max(range[i].start, start); + common_end = min(range[i].end, end); + if (common_start > common_end + 1) + continue; + + final_start = min(range[i].start, start); + final_end = max(range[i].end, end); + + range[i].start = final_start; + range[i].end = final_end; + return nr_range; + } + + /* Need to add it: */ + return add_range(range, az, nr_range, start, end); +} + +void subtract_range(struct range *range, int az, u64 start, u64 end) +{ + int i, j; + + if (start > end) + return; + + for (j = 0; j < az; j++) { + if (!range[j].end) + continue; + + if (start <= range[j].start && end >= range[j].end) { + range[j].start = 0; + range[j].end = 0; + continue; + } + + if (start <= range[j].start && end < range[j].end && + range[j].start < end + 1) { + range[j].start = end + 1; + continue; + } + + + if (start > range[j].start && end >= range[j].end && + range[j].end > start - 1) { + range[j].end = start - 1; + continue; + } + + if (start > range[j].start && end < range[j].end) { + /* Find the new spare: */ + for (i = 0; i < az; i++) { + if (range[i].end == 0) + break; + } + if (i < az) { + range[i].end = range[j].end; + range[i].start = end + 1; + } else { + printk(KERN_ERR "run of slot in ranges\n"); + } + range[j].end = start - 1; + continue; + } + } +} + +static int cmp_range(const void *x1, const void *x2) +{ + const struct range *r1 = x1; + const struct range *r2 = x2; + s64 start1, start2; + + start1 = r1->start; + start2 = r2->start; + + return start1 - start2; +} + +int clean_sort_range(struct range *range, int az) +{ + int i, j, k = az - 1, nr_range = 0; + + for (i = 0; i < k; i++) { + if (range[i].end) + continue; + for (j = k; j > i; j--) { + if (range[j].end) { + k = j; + break; + } + } + if (j == i) + break; + range[i].start = range[k].start; + range[i].end = range[k].end; + range[k].start = 0; + range[k].end = 0; + k--; + } + /* count it */ + for (i = 0; i < az; i++) { + if (!range[i].end) { + nr_range = i; + break; + } + } + + /* sort them */ + sort(range, nr_range, sizeof(struct range), cmp_range, NULL); + + return nr_range; +} + +void sort_range(struct range *range, int nr_range) +{ + /* sort them */ + sort(range, nr_range, sizeof(struct range), cmp_range, NULL); +} -- cgit v1.2.3-18-g5258 From e9a0064ad03b899938059bb576615ad9ed0f27f9 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Wed, 10 Feb 2010 01:20:13 -0800 Subject: x86: Change range end to start+size So make interface more consistent with early_res. Later we can share some code with early_res. Signed-off-by: Yinghai Lu LKML-Reference: <1265793639-15071-10-git-send-email-yinghai@kernel.org> Signed-off-by: H. Peter Anvin --- kernel/range.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/range.c b/kernel/range.c index 71e0021281f..74e2e611492 100644 --- a/kernel/range.c +++ b/kernel/range.c @@ -13,7 +13,7 @@ int add_range(struct range *range, int az, int nr_range, u64 start, u64 end) { - if (start > end) + if (start >= end) return nr_range; /* Out of slots: */ @@ -33,7 +33,7 @@ int add_range_with_merge(struct range *range, int az, int nr_range, { int i; - if (start > end) + if (start >= end) return nr_range; /* Try to merge it with old one: */ @@ -46,7 +46,7 @@ int add_range_with_merge(struct range *range, int az, int nr_range, common_start = max(range[i].start, start); common_end = min(range[i].end, end); - if (common_start > common_end + 1) + if (common_start > common_end) continue; final_start = min(range[i].start, start); @@ -65,7 +65,7 @@ void subtract_range(struct range *range, int az, u64 start, u64 end) { int i, j; - if (start > end) + if (start >= end) return; for (j = 0; j < az; j++) { @@ -79,15 +79,15 @@ void subtract_range(struct range *range, int az, u64 start, u64 end) } if (start <= range[j].start && end < range[j].end && - range[j].start < end + 1) { - range[j].start = end + 1; + range[j].start < end) { + range[j].start = end; continue; } if (start > range[j].start && end >= range[j].end && - range[j].end > start - 1) { - range[j].end = start - 1; + range[j].end > start) { + range[j].end = start; continue; } @@ -99,11 +99,11 @@ void subtract_range(struct range *range, int az, u64 start, u64 end) } if (i < az) { range[i].end = range[j].end; - range[i].start = end + 1; + range[i].start = end; } else { printk(KERN_ERR "run of slot in ranges\n"); } - range[j].end = start - 1; + range[j].end = start; continue; } } -- cgit v1.2.3-18-g5258 From 580e0ad21d6d6f932461d24b47041e3dd499c23f Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 16 Feb 2010 18:40:35 -0800 Subject: core: Move early_res from arch/x86 to kernel/ This makes the range reservation feature available to other architectures. -v2: add get_max_mapped, max_pfn_mapped only defined in x86... to fix PPC compiling -v3: according to hpa, add CONFIG_HAVE_EARLY_RES -v4: fix typo about EARLY_RES in config Signed-off-by: Yinghai Lu LKML-Reference: <4B7B5723.4070009@kernel.org> Signed-off-by: H. Peter Anvin --- kernel/Makefile | 1 + kernel/early_res.c | 513 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 514 insertions(+) create mode 100644 kernel/early_res.c (limited to 'kernel') diff --git a/kernel/Makefile b/kernel/Makefile index ad47330ccf3..1292b863d66 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -11,6 +11,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o \ hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \ notifier.o ksysfs.o pm_qos_params.o sched_clock.o cred.o \ async.o range.o +obj-$(CONFIG_HAVE_EARLY_RES) += early_res.o obj-y += groups.o ifdef CONFIG_FUNCTION_TRACER diff --git a/kernel/early_res.c b/kernel/early_res.c new file mode 100644 index 00000000000..aa5494ac446 --- /dev/null +++ b/kernel/early_res.c @@ -0,0 +1,513 @@ +/* + * early_res, could be used to replace bootmem + */ +#include +#include +#include +#include +#include +#include + +/* + * Early reserved memory areas. + */ +/* + * need to make sure this one is bigger enough before + * find_fw_memmap_area could be used + */ +#define MAX_EARLY_RES_X 32 + +struct early_res { + u64 start, end; + char name[15]; + char overlap_ok; +}; +static struct early_res early_res_x[MAX_EARLY_RES_X] __initdata; + +static int max_early_res __initdata = MAX_EARLY_RES_X; +static struct early_res *early_res __initdata = &early_res_x[0]; +static int early_res_count __initdata; + +static int __init find_overlapped_early(u64 start, u64 end) +{ + int i; + struct early_res *r; + + for (i = 0; i < max_early_res && early_res[i].end; i++) { + r = &early_res[i]; + if (end > r->start && start < r->end) + break; + } + + return i; +} + +/* + * Drop the i-th range from the early reservation map, + * by copying any higher ranges down one over it, and + * clearing what had been the last slot. + */ +static void __init drop_range(int i) +{ + int j; + + for (j = i + 1; j < max_early_res && early_res[j].end; j++) + ; + + memmove(&early_res[i], &early_res[i + 1], + (j - 1 - i) * sizeof(struct early_res)); + + early_res[j - 1].end = 0; + early_res_count--; +} + +/* + * Split any existing ranges that: + * 1) are marked 'overlap_ok', and + * 2) overlap with the stated range [start, end) + * into whatever portion (if any) of the existing range is entirely + * below or entirely above the stated range. Drop the portion + * of the existing range that overlaps with the stated range, + * which will allow the caller of this routine to then add that + * stated range without conflicting with any existing range. + */ +static void __init drop_overlaps_that_are_ok(u64 start, u64 end) +{ + int i; + struct early_res *r; + u64 lower_start, lower_end; + u64 upper_start, upper_end; + char name[15]; + + for (i = 0; i < max_early_res && early_res[i].end; i++) { + r = &early_res[i]; + + /* Continue past non-overlapping ranges */ + if (end <= r->start || start >= r->end) + continue; + + /* + * Leave non-ok overlaps as is; let caller + * panic "Overlapping early reservations" + * when it hits this overlap. + */ + if (!r->overlap_ok) + return; + + /* + * We have an ok overlap. We will drop it from the early + * reservation map, and add back in any non-overlapping + * portions (lower or upper) as separate, overlap_ok, + * non-overlapping ranges. + */ + + /* 1. Note any non-overlapping (lower or upper) ranges. */ + strncpy(name, r->name, sizeof(name) - 1); + + lower_start = lower_end = 0; + upper_start = upper_end = 0; + if (r->start < start) { + lower_start = r->start; + lower_end = start; + } + if (r->end > end) { + upper_start = end; + upper_end = r->end; + } + + /* 2. Drop the original ok overlapping range */ + drop_range(i); + + i--; /* resume for-loop on copied down entry */ + + /* 3. Add back in any non-overlapping ranges. */ + if (lower_end) + reserve_early_overlap_ok(lower_start, lower_end, name); + if (upper_end) + reserve_early_overlap_ok(upper_start, upper_end, name); + } +} + +static void __init __reserve_early(u64 start, u64 end, char *name, + int overlap_ok) +{ + int i; + struct early_res *r; + + i = find_overlapped_early(start, end); + if (i >= max_early_res) + panic("Too many early reservations"); + r = &early_res[i]; + if (r->end) + panic("Overlapping early reservations " + "%llx-%llx %s to %llx-%llx %s\n", + start, end - 1, name ? name : "", r->start, + r->end - 1, r->name); + r->start = start; + r->end = end; + r->overlap_ok = overlap_ok; + if (name) + strncpy(r->name, name, sizeof(r->name) - 1); + early_res_count++; +} + +/* + * A few early reservtations come here. + * + * The 'overlap_ok' in the name of this routine does -not- mean it + * is ok for these reservations to overlap an earlier reservation. + * Rather it means that it is ok for subsequent reservations to + * overlap this one. + * + * Use this entry point to reserve early ranges when you are doing + * so out of "Paranoia", reserving perhaps more memory than you need, + * just in case, and don't mind a subsequent overlapping reservation + * that is known to be needed. + * + * The drop_overlaps_that_are_ok() call here isn't really needed. + * It would be needed if we had two colliding 'overlap_ok' + * reservations, so that the second such would not panic on the + * overlap with the first. We don't have any such as of this + * writing, but might as well tolerate such if it happens in + * the future. + */ +void __init reserve_early_overlap_ok(u64 start, u64 end, char *name) +{ + drop_overlaps_that_are_ok(start, end); + __reserve_early(start, end, name, 1); +} + +static void __init __check_and_double_early_res(u64 ex_start, u64 ex_end) +{ + u64 start, end, size, mem; + struct early_res *new; + + /* do we have enough slots left ? */ + if ((max_early_res - early_res_count) > max(max_early_res/8, 2)) + return; + + /* double it */ + mem = -1ULL; + size = sizeof(struct early_res) * max_early_res * 2; + if (early_res == early_res_x) + start = 0; + else + start = early_res[0].end; + end = ex_start; + if (start + size < end) + mem = find_fw_memmap_area(start, end, size, + sizeof(struct early_res)); + if (mem == -1ULL) { + start = ex_end; + end = get_max_mapped(); + if (start + size < end) + mem = find_fw_memmap_area(start, end, size, + sizeof(struct early_res)); + } + if (mem == -1ULL) + panic("can not find more space for early_res array"); + + new = __va(mem); + /* save the first one for own */ + new[0].start = mem; + new[0].end = mem + size; + new[0].overlap_ok = 0; + /* copy old to new */ + if (early_res == early_res_x) { + memcpy(&new[1], &early_res[0], + sizeof(struct early_res) * max_early_res); + memset(&new[max_early_res+1], 0, + sizeof(struct early_res) * (max_early_res - 1)); + early_res_count++; + } else { + memcpy(&new[1], &early_res[1], + sizeof(struct early_res) * (max_early_res - 1)); + memset(&new[max_early_res], 0, + sizeof(struct early_res) * max_early_res); + } + memset(&early_res[0], 0, sizeof(struct early_res) * max_early_res); + early_res = new; + max_early_res *= 2; + printk(KERN_DEBUG "early_res array is doubled to %d at [%llx - %llx]\n", + max_early_res, mem, mem + size - 1); +} + +/* + * Most early reservations come here. + * + * We first have drop_overlaps_that_are_ok() drop any pre-existing + * 'overlap_ok' ranges, so that we can then reserve this memory + * range without risk of panic'ing on an overlapping overlap_ok + * early reservation. + */ +void __init reserve_early(u64 start, u64 end, char *name) +{ + if (start >= end) + return; + + __check_and_double_early_res(start, end); + + drop_overlaps_that_are_ok(start, end); + __reserve_early(start, end, name, 0); +} + +void __init reserve_early_without_check(u64 start, u64 end, char *name) +{ + struct early_res *r; + + if (start >= end) + return; + + __check_and_double_early_res(start, end); + + r = &early_res[early_res_count]; + + r->start = start; + r->end = end; + r->overlap_ok = 0; + if (name) + strncpy(r->name, name, sizeof(r->name) - 1); + early_res_count++; +} + +void __init free_early(u64 start, u64 end) +{ + struct early_res *r; + int i; + + i = find_overlapped_early(start, end); + r = &early_res[i]; + if (i >= max_early_res || r->end != end || r->start != start) + panic("free_early on not reserved area: %llx-%llx!", + start, end - 1); + + drop_range(i); +} + +#ifdef CONFIG_NO_BOOTMEM +static void __init subtract_early_res(struct range *range, int az) +{ + int i, count; + u64 final_start, final_end; + int idx = 0; + + count = 0; + for (i = 0; i < max_early_res && early_res[i].end; i++) + count++; + + /* need to skip first one ?*/ + if (early_res != early_res_x) + idx = 1; + +#define DEBUG_PRINT_EARLY_RES 1 + +#if DEBUG_PRINT_EARLY_RES + printk(KERN_INFO "Subtract (%d early reservations)\n", count); +#endif + for (i = idx; i < count; i++) { + struct early_res *r = &early_res[i]; +#if DEBUG_PRINT_EARLY_RES + printk(KERN_INFO " #%d [%010llx - %010llx] %15s\n", i, + r->start, r->end, r->name); +#endif + final_start = PFN_DOWN(r->start); + final_end = PFN_UP(r->end); + if (final_start >= final_end) + continue; + subtract_range(range, az, final_start, final_end); + } + +} + +int __init get_free_all_memory_range(struct range **rangep, int nodeid) +{ + int i, count; + u64 start = 0, end; + u64 size; + u64 mem; + struct range *range; + int nr_range; + + count = 0; + for (i = 0; i < max_early_res && early_res[i].end; i++) + count++; + + count *= 2; + + size = sizeof(struct range) * count; + end = get_max_mapped(); +#ifdef MAX_DMA32_PFN + if (end > (MAX_DMA32_PFN << PAGE_SHIFT)) + start = MAX_DMA32_PFN << PAGE_SHIFT; +#endif + mem = find_fw_memmap_area(start, end, size, sizeof(struct range)); + if (mem == -1ULL) + panic("can not find more space for range free"); + + range = __va(mem); + /* use early_node_map[] and early_res to get range array at first */ + memset(range, 0, size); + nr_range = 0; + + /* need to go over early_node_map to find out good range for node */ + nr_range = add_from_early_node_map(range, count, nr_range, nodeid); +#ifdef CONFIG_X86_32 + subtract_range(range, count, max_low_pfn, -1ULL); +#endif + subtract_early_res(range, count); + nr_range = clean_sort_range(range, count); + + /* need to clear it ? */ + if (nodeid == MAX_NUMNODES) { + memset(&early_res[0], 0, + sizeof(struct early_res) * max_early_res); + early_res = NULL; + max_early_res = 0; + } + + *rangep = range; + return nr_range; +} +#else +void __init early_res_to_bootmem(u64 start, u64 end) +{ + int i, count; + u64 final_start, final_end; + int idx = 0; + + count = 0; + for (i = 0; i < max_early_res && early_res[i].end; i++) + count++; + + /* need to skip first one ?*/ + if (early_res != early_res_x) + idx = 1; + + printk(KERN_INFO "(%d/%d early reservations) ==> bootmem [%010llx - %010llx]\n", + count - idx, max_early_res, start, end); + for (i = idx; i < count; i++) { + struct early_res *r = &early_res[i]; + printk(KERN_INFO " #%d [%010llx - %010llx] %16s", i, + r->start, r->end, r->name); + final_start = max(start, r->start); + final_end = min(end, r->end); + if (final_start >= final_end) { + printk(KERN_CONT "\n"); + continue; + } + printk(KERN_CONT " ==> [%010llx - %010llx]\n", + final_start, final_end); + reserve_bootmem_generic(final_start, final_end - final_start, + BOOTMEM_DEFAULT); + } + /* clear them */ + memset(&early_res[0], 0, sizeof(struct early_res) * max_early_res); + early_res = NULL; + max_early_res = 0; + early_res_count = 0; +} +#endif + +/* Check for already reserved areas */ +static inline int __init bad_addr(u64 *addrp, u64 size, u64 align) +{ + int i; + u64 addr = *addrp; + int changed = 0; + struct early_res *r; +again: + i = find_overlapped_early(addr, addr + size); + r = &early_res[i]; + if (i < max_early_res && r->end) { + *addrp = addr = round_up(r->end, align); + changed = 1; + goto again; + } + return changed; +} + +/* Check for already reserved areas */ +static inline int __init bad_addr_size(u64 *addrp, u64 *sizep, u64 align) +{ + int i; + u64 addr = *addrp, last; + u64 size = *sizep; + int changed = 0; +again: + last = addr + size; + for (i = 0; i < max_early_res && early_res[i].end; i++) { + struct early_res *r = &early_res[i]; + if (last > r->start && addr < r->start) { + size = r->start - addr; + changed = 1; + goto again; + } + if (last > r->end && addr < r->end) { + addr = round_up(r->end, align); + size = last - addr; + changed = 1; + goto again; + } + if (last <= r->end && addr >= r->start) { + (*sizep)++; + return 0; + } + } + if (changed) { + *addrp = addr; + *sizep = size; + } + return changed; +} + +/* + * Find a free area with specified alignment in a specific range. + * only with the area.between start to end is active range from early_node_map + * so they are good as RAM + */ +u64 __init find_early_area(u64 ei_start, u64 ei_last, u64 start, u64 end, + u64 size, u64 align) +{ + u64 addr, last; + + addr = round_up(ei_start, align); + if (addr < start) + addr = round_up(start, align); + if (addr >= ei_last) + goto out; + while (bad_addr(&addr, size, align) && addr+size <= ei_last) + ; + last = addr + size; + if (last > ei_last) + goto out; + if (last > end) + goto out; + + return addr; + +out: + return -1ULL; +} + +u64 __init find_early_area_size(u64 ei_start, u64 ei_last, u64 start, + u64 *sizep, u64 align) +{ + u64 addr, last; + + addr = round_up(ei_start, align); + if (addr < start) + addr = round_up(start, align); + if (addr >= ei_last) + goto out; + *sizep = ei_last - addr; + while (bad_addr_size(&addr, sizep, align) && addr + *sizep <= ei_last) + ; + last = addr + *sizep; + if (last > ei_last) + goto out; + + return addr; + +out: + return -1ULL; +} -- cgit v1.2.3-18-g5258 From fb90ef93df654f2678933efbbf864adac0ae490e Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Wed, 24 Feb 2010 18:36:53 -0800 Subject: early_res: Add free_early_partial() To free partial areas in pcpu_setup... Reported-by: Peter Zijlstra Signed-off-by: Yinghai Lu Cc: Tejun Heo Cc: Christoph Lameter Cc: Stephen Rothwell Cc: Linus Torvalds Cc: Jesse Barnes Cc: Pekka Enberg LKML-Reference: <4B85E245.5030001@kernel.org> Signed-off-by: Ingo Molnar --- kernel/early_res.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) (limited to 'kernel') diff --git a/kernel/early_res.c b/kernel/early_res.c index aa5494ac446..9ab11cd8485 100644 --- a/kernel/early_res.c +++ b/kernel/early_res.c @@ -61,6 +61,40 @@ static void __init drop_range(int i) early_res_count--; } +static void __init drop_range_partial(int i, u64 start, u64 end) +{ + u64 common_start, common_end; + u64 old_start, old_end; + + old_start = early_res[i].start; + old_end = early_res[i].end; + common_start = max(old_start, start); + common_end = min(old_end, end); + + /* no overlap ? */ + if (common_start >= common_end) + return; + + if (old_start < common_start) { + /* make head segment */ + early_res[i].end = common_start; + if (old_end > common_end) { + /* add another for left over on tail */ + reserve_early_without_check(common_end, old_end, + early_res[i].name); + } + return; + } else { + if (old_end > common_end) { + /* reuse the entry for tail left */ + early_res[i].start = common_end; + return; + } + /* all covered */ + drop_range(i); + } +} + /* * Split any existing ranges that: * 1) are marked 'overlap_ok', and @@ -284,6 +318,27 @@ void __init free_early(u64 start, u64 end) drop_range(i); } +void __init free_early_partial(u64 start, u64 end) +{ + struct early_res *r; + int i; + +try_next: + i = find_overlapped_early(start, end); + if (i >= max_early_res) + return; + + r = &early_res[i]; + /* hole ? */ + if (r->end >= end && r->start <= start) { + drop_range_partial(i, start, end); + return; + } + + drop_range_partial(i, start, end); + goto try_next; +} + #ifdef CONFIG_NO_BOOTMEM static void __init subtract_early_res(struct range *range, int az) { -- cgit v1.2.3-18-g5258 From dce46a04d55d6358d2d4ab44a4946a19f9425fe2 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Mon, 1 Mar 2010 18:48:52 -0800 Subject: early_res: Need to save the allocation name in drop_range_partial() During free_early_partial(), reserve_early_without_check() could end extending the early_res area from __check_and_double_early_res(); as a result, the location of the name for the current reservation could change. Therefore, we need to save a local copy of the name. [ hpa: rewrote comment and checkin description ] Signed-off-by: Yinghai Lu LKML-Reference: <4B8C7C94.7070000@kernel.org> Signed-off-by: H. Peter Anvin --- kernel/early_res.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/early_res.c b/kernel/early_res.c index 9ab11cd8485..3cb2c661bb7 100644 --- a/kernel/early_res.c +++ b/kernel/early_res.c @@ -79,9 +79,19 @@ static void __init drop_range_partial(int i, u64 start, u64 end) /* make head segment */ early_res[i].end = common_start; if (old_end > common_end) { + char name[15]; + + /* + * Save a local copy of the name, since the + * early_res array could get resized inside + * reserve_early_without_check() -> + * __check_and_double_early_res(), which would + * make the current name pointer invalid. + */ + strncpy(name, early_res[i].name, + sizeof(early_res[i].name) - 1); /* add another for left over on tail */ - reserve_early_without_check(common_end, old_end, - early_res[i].name); + reserve_early_without_check(common_end, old_end, name); } return; } else { -- cgit v1.2.3-18-g5258