linux/arch/x86/mm/init.c

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include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/gfp.h>
#include <linux/initrd.h>
#include <linux/ioport.h>
#include <linux/swap.h>
#include <asm/cacheflush.h>
#include <asm/e820.h>
#include <asm/init.h>
#include <asm/page.h>
#include <asm/page_types.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/system.h>
#include <asm/tlbflush.h>
#include <asm/tlb.h>
#include <asm/proto.h>
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
unsigned long __initdata e820_table_start;
unsigned long __meminitdata e820_table_end;
unsigned long __meminitdata e820_table_top;
int after_bootmem;
int direct_gbpages
#ifdef CONFIG_DIRECT_GBPAGES
= 1
#endif
;
static void __init find_early_table_space(unsigned long end, int use_pse,
int use_gbpages)
{
unsigned long puds, pmds, ptes, tables, start;
puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);
if (use_gbpages) {
unsigned long extra;
extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT;
} else
pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE);
if (use_pse) {
unsigned long extra;
extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
#ifdef CONFIG_X86_32
extra += PMD_SIZE;
#endif
ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
} else
ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE);
#ifdef CONFIG_X86_32
/* for fixmap */
tables += roundup(__end_of_fixed_addresses * sizeof(pte_t), PAGE_SIZE);
#endif
/*
* RED-PEN putting page tables only on node 0 could
* cause a hotspot and fill up ZONE_DMA. The page tables
* need roughly 0.5KB per GB.
*/
#ifdef CONFIG_X86_32
start = 0x7000;
#else
start = 0x8000;
#endif
e820_table_start = find_e820_area(start, max_pfn_mapped<<PAGE_SHIFT,
tables, PAGE_SIZE);
if (e820_table_start == -1UL)
panic("Cannot find space for the kernel page tables");
e820_table_start >>= PAGE_SHIFT;
e820_table_end = e820_table_start;
e820_table_top = e820_table_start + (tables >> PAGE_SHIFT);
printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
end, e820_table_start << PAGE_SHIFT, e820_table_top << PAGE_SHIFT);
}
struct map_range {
unsigned long start;
unsigned long end;
unsigned page_size_mask;
};
#ifdef CONFIG_X86_32
#define NR_RANGE_MR 3
#else /* CONFIG_X86_64 */
#define NR_RANGE_MR 5
#endif
static int __meminit save_mr(struct map_range *mr, int nr_range,
unsigned long start_pfn, unsigned long end_pfn,
unsigned long page_size_mask)
{
if (start_pfn < end_pfn) {
if (nr_range >= NR_RANGE_MR)
panic("run out of range for init_memory_mapping\n");
mr[nr_range].start = start_pfn<<PAGE_SHIFT;
mr[nr_range].end = end_pfn<<PAGE_SHIFT;
mr[nr_range].page_size_mask = page_size_mask;
nr_range++;
}
return nr_range;
}
/*
* Setup the direct mapping of the physical memory at PAGE_OFFSET.
* This runs before bootmem is initialized and gets pages directly from
* the physical memory. To access them they are temporarily mapped.
*/
unsigned long __init_refok init_memory_mapping(unsigned long start,
unsigned long end)
{
unsigned long page_size_mask = 0;
unsigned long start_pfn, end_pfn;
unsigned long ret = 0;
unsigned long pos;
struct map_range mr[NR_RANGE_MR];
int nr_range, i;
int use_pse, use_gbpages;
printk(KERN_INFO "init_memory_mapping: %016lx-%016lx\n", start, end);
#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK)
/*
* For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
* This will simplify cpa(), which otherwise needs to support splitting
* large pages into small in interrupt context, etc.
*/
use_pse = use_gbpages = 0;
#else
use_pse = cpu_has_pse;
use_gbpages = direct_gbpages;
#endif
/* Enable PSE if available */
if (cpu_has_pse)
set_in_cr4(X86_CR4_PSE);
/* Enable PGE if available */
if (cpu_has_pge) {
set_in_cr4(X86_CR4_PGE);
__supported_pte_mask |= _PAGE_GLOBAL;
}
if (use_gbpages)
page_size_mask |= 1 << PG_LEVEL_1G;
if (use_pse)
page_size_mask |= 1 << PG_LEVEL_2M;
memset(mr, 0, sizeof(mr));
nr_range = 0;
/* head if not big page alignment ? */
start_pfn = start >> PAGE_SHIFT;
pos = start_pfn << PAGE_SHIFT;
#ifdef CONFIG_X86_32
/*
* Don't use a large page for the first 2/4MB of memory
* because there are often fixed size MTRRs in there
* and overlapping MTRRs into large pages can cause
* slowdowns.
*/
if (pos == 0)
end_pfn = 1<<(PMD_SHIFT - PAGE_SHIFT);
else
end_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
<< (PMD_SHIFT - PAGE_SHIFT);
#else /* CONFIG_X86_64 */
end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT)
<< (PMD_SHIFT - PAGE_SHIFT);
#endif
if (end_pfn > (end >> PAGE_SHIFT))
end_pfn = end >> PAGE_SHIFT;
if (start_pfn < end_pfn) {
nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
pos = end_pfn << PAGE_SHIFT;
}
/* big page (2M) range */
start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
<< (PMD_SHIFT - PAGE_SHIFT);
#ifdef CONFIG_X86_32
end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
#else /* CONFIG_X86_64 */
end_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
<< (PUD_SHIFT - PAGE_SHIFT);
if (end_pfn > ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT)))
end_pfn = ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT));
#endif
if (start_pfn < end_pfn) {
nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
page_size_mask & (1<<PG_LEVEL_2M));
pos = end_pfn << PAGE_SHIFT;
}
#ifdef CONFIG_X86_64
/* big page (1G) range */
start_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
<< (PUD_SHIFT - PAGE_SHIFT);
end_pfn = (end >> PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
if (start_pfn < end_pfn) {
nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
page_size_mask &
((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
pos = end_pfn << PAGE_SHIFT;
}
/* tail is not big page (1G) alignment */
start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
<< (PMD_SHIFT - PAGE_SHIFT);
end_pfn = (end >> PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
if (start_pfn < end_pfn) {
nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
page_size_mask & (1<<PG_LEVEL_2M));
pos = end_pfn << PAGE_SHIFT;
}
#endif
/* tail is not big page (2M) alignment */
start_pfn = pos>>PAGE_SHIFT;
end_pfn = end>>PAGE_SHIFT;
nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
/* try to merge same page size and continuous */
for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
unsigned long old_start;
if (mr[i].end != mr[i+1].start ||
mr[i].page_size_mask != mr[i+1].page_size_mask)
continue;
/* move it */
old_start = mr[i].start;
memmove(&mr[i], &mr[i+1],
(nr_range - 1 - i) * sizeof(struct map_range));
mr[i--].start = old_start;
nr_range--;
}
for (i = 0; i < nr_range; i++)
printk(KERN_DEBUG " %010lx - %010lx page %s\n",
mr[i].start, mr[i].end,
(mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
(mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
/*
* Find space for the kernel direct mapping tables.
*
* Later we should allocate these tables in the local node of the
* memory mapped. Unfortunately this is done currently before the
* nodes are discovered.
*/
if (!after_bootmem)
find_early_table_space(end, use_pse, use_gbpages);
for (i = 0; i < nr_range; i++)
ret = kernel_physical_mapping_init(mr[i].start, mr[i].end,
mr[i].page_size_mask);
#ifdef CONFIG_X86_32
early_ioremap_page_table_range_init();
load_cr3(swapper_pg_dir);
#endif
#ifdef CONFIG_X86_64
if (!after_bootmem && !start) {
pud_t *pud;
pmd_t *pmd;
mmu_cr4_features = read_cr4();
/*
* _brk_end cannot change anymore, but it and _end may be
* located on different 2M pages. cleanup_highmap(), however,
* can only consider _end when it runs, so destroy any
* mappings beyond _brk_end here.
*/
pud = pud_offset(pgd_offset_k(_brk_end), _brk_end);
pmd = pmd_offset(pud, _brk_end - 1);
while (++pmd <= pmd_offset(pud, (unsigned long)_end - 1))
pmd_clear(pmd);
}
#endif
__flush_tlb_all();
if (!after_bootmem && e820_table_end > e820_table_start)
reserve_early(e820_table_start << PAGE_SHIFT,
e820_table_end << PAGE_SHIFT, "PGTABLE");
if (!after_bootmem)
early_memtest(start, end);
return ret >> PAGE_SHIFT;
}
/*
* devmem_is_allowed() checks to see if /dev/mem access to a certain address
* is valid. The argument is a physical page number.
*
*
* On x86, access has to be given to the first megabyte of ram because that area
* contains bios code and data regions used by X and dosemu and similar apps.
* Access has to be given to non-kernel-ram areas as well, these contain the PCI
* mmio resources as well as potential bios/acpi data regions.
*/
int devmem_is_allowed(unsigned long pagenr)
{
if (pagenr <= 256)
return 1;
if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
return 0;
if (!page_is_ram(pagenr))
return 1;
return 0;
}
void free_init_pages(char *what, unsigned long begin, unsigned long end)
{
x86: Make sure free_init_pages() frees pages on page boundary When CONFIG_NO_BOOTMEM=y, it could use memory more effiently, or in a more compact fashion. Example: Allocated new RAMDISK: 00ec2000 - 0248ce57 Move RAMDISK from 000000002ea04000 - 000000002ffcee56 to 00ec2000 - 0248ce56 The new RAMDISK's end is not page aligned. Last page could be shared with other users. When free_init_pages are called for initrd or .init, the page could be freed and we could corrupt other data. code segment in free_init_pages(): | for (; addr < end; addr += PAGE_SIZE) { | ClearPageReserved(virt_to_page(addr)); | init_page_count(virt_to_page(addr)); | memset((void *)(addr & ~(PAGE_SIZE-1)), | POISON_FREE_INITMEM, PAGE_SIZE); | free_page(addr); | totalram_pages++; | } last half page could be used as one whole free page. So page align the boundaries. -v2: make the original initramdisk to be aligned, according to Johannes, otherwise we have the chance to lose one page. we still need to keep initrd_end not aligned, otherwise it could confuse decompressor. -v3: change to WARN_ON instead, suggested by Johannes. -v4: use PAGE_ALIGN, suggested by Johannes. We may fix that macro name later to PAGE_ALIGN_UP, and PAGE_ALIGN_DOWN Add comments about assuming ramdisk start is aligned in relocate_initrd(), change to re get ramdisk_image instead of save it to make diff smaller. Add warning for wrong range, suggested by Johannes. -v6: remove one WARN() We need to align beginning in free_init_pages() do not copy more than ramdisk_size, noticed by Johannes Reported-by: Stanislaw Gruszka <sgruszka@redhat.com> Tested-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: David Miller <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <1269830604-26214-3-git-send-email-yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-29 02:42:55 +00:00
unsigned long addr;
unsigned long begin_aligned, end_aligned;
x86: Make sure free_init_pages() frees pages on page boundary When CONFIG_NO_BOOTMEM=y, it could use memory more effiently, or in a more compact fashion. Example: Allocated new RAMDISK: 00ec2000 - 0248ce57 Move RAMDISK from 000000002ea04000 - 000000002ffcee56 to 00ec2000 - 0248ce56 The new RAMDISK's end is not page aligned. Last page could be shared with other users. When free_init_pages are called for initrd or .init, the page could be freed and we could corrupt other data. code segment in free_init_pages(): | for (; addr < end; addr += PAGE_SIZE) { | ClearPageReserved(virt_to_page(addr)); | init_page_count(virt_to_page(addr)); | memset((void *)(addr & ~(PAGE_SIZE-1)), | POISON_FREE_INITMEM, PAGE_SIZE); | free_page(addr); | totalram_pages++; | } last half page could be used as one whole free page. So page align the boundaries. -v2: make the original initramdisk to be aligned, according to Johannes, otherwise we have the chance to lose one page. we still need to keep initrd_end not aligned, otherwise it could confuse decompressor. -v3: change to WARN_ON instead, suggested by Johannes. -v4: use PAGE_ALIGN, suggested by Johannes. We may fix that macro name later to PAGE_ALIGN_UP, and PAGE_ALIGN_DOWN Add comments about assuming ramdisk start is aligned in relocate_initrd(), change to re get ramdisk_image instead of save it to make diff smaller. Add warning for wrong range, suggested by Johannes. -v6: remove one WARN() We need to align beginning in free_init_pages() do not copy more than ramdisk_size, noticed by Johannes Reported-by: Stanislaw Gruszka <sgruszka@redhat.com> Tested-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: David Miller <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <1269830604-26214-3-git-send-email-yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-29 02:42:55 +00:00
/* Make sure boundaries are page aligned */
begin_aligned = PAGE_ALIGN(begin);
end_aligned = end & PAGE_MASK;
if (WARN_ON(begin_aligned != begin || end_aligned != end)) {
begin = begin_aligned;
end = end_aligned;
}
if (begin >= end)
return;
x86: Make sure free_init_pages() frees pages on page boundary When CONFIG_NO_BOOTMEM=y, it could use memory more effiently, or in a more compact fashion. Example: Allocated new RAMDISK: 00ec2000 - 0248ce57 Move RAMDISK from 000000002ea04000 - 000000002ffcee56 to 00ec2000 - 0248ce56 The new RAMDISK's end is not page aligned. Last page could be shared with other users. When free_init_pages are called for initrd or .init, the page could be freed and we could corrupt other data. code segment in free_init_pages(): | for (; addr < end; addr += PAGE_SIZE) { | ClearPageReserved(virt_to_page(addr)); | init_page_count(virt_to_page(addr)); | memset((void *)(addr & ~(PAGE_SIZE-1)), | POISON_FREE_INITMEM, PAGE_SIZE); | free_page(addr); | totalram_pages++; | } last half page could be used as one whole free page. So page align the boundaries. -v2: make the original initramdisk to be aligned, according to Johannes, otherwise we have the chance to lose one page. we still need to keep initrd_end not aligned, otherwise it could confuse decompressor. -v3: change to WARN_ON instead, suggested by Johannes. -v4: use PAGE_ALIGN, suggested by Johannes. We may fix that macro name later to PAGE_ALIGN_UP, and PAGE_ALIGN_DOWN Add comments about assuming ramdisk start is aligned in relocate_initrd(), change to re get ramdisk_image instead of save it to make diff smaller. Add warning for wrong range, suggested by Johannes. -v6: remove one WARN() We need to align beginning in free_init_pages() do not copy more than ramdisk_size, noticed by Johannes Reported-by: Stanislaw Gruszka <sgruszka@redhat.com> Tested-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: David Miller <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <1269830604-26214-3-git-send-email-yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-29 02:42:55 +00:00
addr = begin;
/*
* If debugging page accesses then do not free this memory but
* mark them not present - any buggy init-section access will
* create a kernel page fault:
*/
#ifdef CONFIG_DEBUG_PAGEALLOC
printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
x86: Make sure free_init_pages() frees pages on page boundary When CONFIG_NO_BOOTMEM=y, it could use memory more effiently, or in a more compact fashion. Example: Allocated new RAMDISK: 00ec2000 - 0248ce57 Move RAMDISK from 000000002ea04000 - 000000002ffcee56 to 00ec2000 - 0248ce56 The new RAMDISK's end is not page aligned. Last page could be shared with other users. When free_init_pages are called for initrd or .init, the page could be freed and we could corrupt other data. code segment in free_init_pages(): | for (; addr < end; addr += PAGE_SIZE) { | ClearPageReserved(virt_to_page(addr)); | init_page_count(virt_to_page(addr)); | memset((void *)(addr & ~(PAGE_SIZE-1)), | POISON_FREE_INITMEM, PAGE_SIZE); | free_page(addr); | totalram_pages++; | } last half page could be used as one whole free page. So page align the boundaries. -v2: make the original initramdisk to be aligned, according to Johannes, otherwise we have the chance to lose one page. we still need to keep initrd_end not aligned, otherwise it could confuse decompressor. -v3: change to WARN_ON instead, suggested by Johannes. -v4: use PAGE_ALIGN, suggested by Johannes. We may fix that macro name later to PAGE_ALIGN_UP, and PAGE_ALIGN_DOWN Add comments about assuming ramdisk start is aligned in relocate_initrd(), change to re get ramdisk_image instead of save it to make diff smaller. Add warning for wrong range, suggested by Johannes. -v6: remove one WARN() We need to align beginning in free_init_pages() do not copy more than ramdisk_size, noticed by Johannes Reported-by: Stanislaw Gruszka <sgruszka@redhat.com> Tested-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: David Miller <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <1269830604-26214-3-git-send-email-yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-29 02:42:55 +00:00
begin, end);
set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
#else
/*
* We just marked the kernel text read only above, now that
* we are going to free part of that, we need to make that
* writeable first.
*/
set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
for (; addr < end; addr += PAGE_SIZE) {
ClearPageReserved(virt_to_page(addr));
init_page_count(virt_to_page(addr));
x86: Make sure free_init_pages() frees pages on page boundary When CONFIG_NO_BOOTMEM=y, it could use memory more effiently, or in a more compact fashion. Example: Allocated new RAMDISK: 00ec2000 - 0248ce57 Move RAMDISK from 000000002ea04000 - 000000002ffcee56 to 00ec2000 - 0248ce56 The new RAMDISK's end is not page aligned. Last page could be shared with other users. When free_init_pages are called for initrd or .init, the page could be freed and we could corrupt other data. code segment in free_init_pages(): | for (; addr < end; addr += PAGE_SIZE) { | ClearPageReserved(virt_to_page(addr)); | init_page_count(virt_to_page(addr)); | memset((void *)(addr & ~(PAGE_SIZE-1)), | POISON_FREE_INITMEM, PAGE_SIZE); | free_page(addr); | totalram_pages++; | } last half page could be used as one whole free page. So page align the boundaries. -v2: make the original initramdisk to be aligned, according to Johannes, otherwise we have the chance to lose one page. we still need to keep initrd_end not aligned, otherwise it could confuse decompressor. -v3: change to WARN_ON instead, suggested by Johannes. -v4: use PAGE_ALIGN, suggested by Johannes. We may fix that macro name later to PAGE_ALIGN_UP, and PAGE_ALIGN_DOWN Add comments about assuming ramdisk start is aligned in relocate_initrd(), change to re get ramdisk_image instead of save it to make diff smaller. Add warning for wrong range, suggested by Johannes. -v6: remove one WARN() We need to align beginning in free_init_pages() do not copy more than ramdisk_size, noticed by Johannes Reported-by: Stanislaw Gruszka <sgruszka@redhat.com> Tested-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: David Miller <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <1269830604-26214-3-git-send-email-yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-29 02:42:55 +00:00
memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
free_page(addr);
totalram_pages++;
}
#endif
}
void free_initmem(void)
{
free_init_pages("unused kernel memory",
(unsigned long)(&__init_begin),
(unsigned long)(&__init_end));
}
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
x86: Make sure free_init_pages() frees pages on page boundary When CONFIG_NO_BOOTMEM=y, it could use memory more effiently, or in a more compact fashion. Example: Allocated new RAMDISK: 00ec2000 - 0248ce57 Move RAMDISK from 000000002ea04000 - 000000002ffcee56 to 00ec2000 - 0248ce56 The new RAMDISK's end is not page aligned. Last page could be shared with other users. When free_init_pages are called for initrd or .init, the page could be freed and we could corrupt other data. code segment in free_init_pages(): | for (; addr < end; addr += PAGE_SIZE) { | ClearPageReserved(virt_to_page(addr)); | init_page_count(virt_to_page(addr)); | memset((void *)(addr & ~(PAGE_SIZE-1)), | POISON_FREE_INITMEM, PAGE_SIZE); | free_page(addr); | totalram_pages++; | } last half page could be used as one whole free page. So page align the boundaries. -v2: make the original initramdisk to be aligned, according to Johannes, otherwise we have the chance to lose one page. we still need to keep initrd_end not aligned, otherwise it could confuse decompressor. -v3: change to WARN_ON instead, suggested by Johannes. -v4: use PAGE_ALIGN, suggested by Johannes. We may fix that macro name later to PAGE_ALIGN_UP, and PAGE_ALIGN_DOWN Add comments about assuming ramdisk start is aligned in relocate_initrd(), change to re get ramdisk_image instead of save it to make diff smaller. Add warning for wrong range, suggested by Johannes. -v6: remove one WARN() We need to align beginning in free_init_pages() do not copy more than ramdisk_size, noticed by Johannes Reported-by: Stanislaw Gruszka <sgruszka@redhat.com> Tested-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: David Miller <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <1269830604-26214-3-git-send-email-yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-29 02:42:55 +00:00
/*
* end could be not aligned, and We can not align that,
* decompresser could be confused by aligned initrd_end
* We already reserve the end partial page before in
* - i386_start_kernel()
* - x86_64_start_kernel()
* - relocate_initrd()
* So here We can do PAGE_ALIGN() safely to get partial page to be freed
*/
free_init_pages("initrd memory", start, PAGE_ALIGN(end));
}
#endif