x86: Fix typo in mark_rodata_ro
PATCH 1/3 x86: Fix typo in mark_rodata_ro
In the comment, should use cleanup_highmap(). and also remove not needed cast for _brk_end, as it is unsigned long.
--- arch/x86/mm/init_64.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
arch/x86/mm/init_64.c +2 -2
@@ -1145,9 +1145,9 @@ void mark_rodata_ro(void)* of the PMD will remain mapped executable. * * Any PMD which was setup after the one which covers _brk_end -* has been zapped already via cleanup_highmem(). +* has been zapped already via cleanup_highmap(). */ - all_end =roundup ((unsigned long )_brk_end,PMD_SIZE ); + all_end =roundup (_brk_end,PMD_SIZE );set_memory_nx (rodata_start, (all_end - rodata_start) >>PAGE_SHIFT );rodata_test ();
PATCH 2/3 x86, 64bit: add pfn_range_is_highmapped()
Need to use it to support holes in highmap when remove not used range in highmap.
--- arch/x86/include/asm/pgtable_64.h | 2 ++ arch/x86/mm/init_64.c | 22 ++++++++++++++++++++++ arch/x86/mm/pageattr.c | 16 +--------------- 3 files changed, 25 insertions(+), 15 deletions(-)
arch/x86/mm/init_64.c +22 -0
@@ -378,6 +378,23 @@ void __init init_extra_mapping_uc(unsign__init_extra_mapping (phys, size, _PAGE_CACHE_MODE_UC); } +/* three holes at most*/ +#define NR_RANGE 4 +static struct range pfn_highmapped[NR_RANGE ]; +static int nr_pfn_highmapped; + +int pfn_range_is_highmapped (unsigned long start_pfn,unsigned long end_pfn) +{ +int i; + +for (i =0 ; i < nr_pfn_highmapped; i++) +if ((start_pfn >= pfn_highmapped[i].start) && + (end_pfn <= pfn_highmapped[i].end)) +return 1 ; + +return 0 ; +} +/* * The head.S code sets up the kernel high mapping: *
@@ -412,6 +429,11 @@ void __init cleanup_highmap(void)if (vaddr < (unsigned long ) _text || vaddr > end)set_pmd (pmd,__pmd (0 )); } + + nr_pfn_highmapped =add_range (pfn_highmapped,NR_RANGE , + nr_pfn_highmapped, +__pa_symbol (_text) >>PAGE_SHIFT , +__pa_symbol (roundup (_brk_end,PMD_SIZE )) >>PAGE_SHIFT ); } static unsigned long __meminit
arch/x86/mm/pageattr.c +1 -15
@@ -91,20 +91,6 @@ void arch_report_meminfo(struct seq_filestatic inline void split_page_count (int level) { }#endif -#ifdef CONFIG_X86_64 - -static inline unsigned long highmap_start_pfn (void ) -{ -return __pa_symbol (_text) >>PAGE_SHIFT ; -} - -static inline unsigned long highmap_end_pfn (void ) -{ -return __pa_symbol (roundup (_brk_end,PMD_SIZE )) >>PAGE_SHIFT ; -} - -#endif -#ifdef CONFIG_DEBUG_PAGEALLOC # define debug_pagealloc 1#else
@@ -1255,7 +1241,7 @@ static int cpa_process_alias(struct cpa_* to touch the high mapped kernel as well: */ if (!within (vaddr, (unsigned long )_text, _brk_end) && -within (cpa->pfn,highmap_start_pfn (),highmap_end_pfn ())) { +pfn_range_is_highmapped (cpa->pfn,1 )) {unsigned long temp_cpa_vaddr = (cpa->pfn <<PAGE_SHIFT ) + __START_KERNEL_map - phys_base; alias_cpa = *cpa;
arch/x86/include/asm/pgtable_64.h +2 -0
@@ -167,6 +167,8 @@ static inline int pgd_large(pgd_t pgd) {extern int kern_addr_valid (unsigned long addr);extern void cleanup_highmap (void ); +int pfn_range_is_highmapped (unsigned long start_pfn,unsigned long end_pfn); +#define HAVE_ARCH_UNMAPPED_AREA #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
PATCH 3/4 x86, 64bit: remove highmap for not needed ranges
In reply to Yinghai Luadd cleanup_highmap_late to remove highmap for initmem, around rodata, and [_brk_end, all_end).
Kernel Layout:
[ 0.000000] .text: [0x01000000-0x0200df88] [ 0.000000] .rodata: [0x02200000-0x02a1dfff] [ 0.000000] .data: [0x02c00000-0x02e510ff] [ 0.000000] .init: [0x02e53000-0x03213fff] [ 0.000000] .bss: [0x03222000-0x0437cfff] [ 0.000000] .brk: [0x0437d000-0x043a2fff]
Actually used brk:
[ 0.270365] memblock_reserve: [0x0000000437d000-0x00000004383fff] flags 0x0 BRK
Before patch:
---[ High Kernel Mapping ]---
---[ High Kernel Mapping ]---
0xffffffff80000000-0xffffffff81000000 16M pmd 0xffffffff81000000-0xffffffff82000000 16M ro PSE GLB x pmd 0xffffffff82000000-0xffffffff82011000 68K ro GLB x pte 0xffffffff82011000-0xffffffff82200000 1980K RW GLB x pte 0xffffffff82200000-0xffffffff82a00000 8M ro PSE GLB NX pmd 0xffffffff82a00000-0xffffffff82a1e000 120K ro GLB NX pte 0xffffffff82a1e000-0xffffffff82c00000 1928K RW GLB NX pte 0xffffffff82c00000-0xffffffff82e00000 2M RW PSE GLB NX pmd 0xffffffff82e00000-0xffffffff83000000 2M RW GLB NX pte 0xffffffff83000000-0xffffffff83200000 2M RW PSE GLB NX pmd 0xffffffff83200000-0xffffffff83400000 2M RW GLB NX pte 0xffffffff83400000-0xffffffff84400000 16M RW PSE GLB NX pmd
0xffffffff84400000-0xffffffffa0000000 444M pmd
After patch:
---[ High Kernel Mapping ]---
0xffffffff80000000-0xffffffff81000000 16M pmd 0xffffffff81000000-0xffffffff82000000 16M ro PSE GLB x pmd 0xffffffff82000000-0xffffffff82012000 72K ro GLB x pte 0xffffffff82012000-0xffffffff82200000 1976K pte
0xffffffff82200000-0xffffffff82a00000 8M ro PSE GLB NX pmd
0xffffffff82a00000-0xffffffff82a1e000 120K ro GLB NX pte
0xffffffff82a1e000-0xffffffff82c00000 1928K pte
0xffffffff82c00000-0xffffffff82e00000 2M RW PSE GLB NX pmd
0xffffffff82e00000-0xffffffff82e53000 332K RW GLB NX pte
0xffffffff82e53000-0xffffffff83000000 1716K pte 0xffffffff83000000-0xffffffff83200000 2M pmd 0xffffffff83200000-0xffffffff83214000 80K pte 0xffffffff83214000-0xffffffff83400000 1968K RW GLB NX pte 0xffffffff83400000-0xffffffff84200000 14M RW PSE GLB NX pmd 0xffffffff84200000-0xffffffff84384000 1552K RW GLB NX pte 0xffffffff84384000-0xffffffff84400000 496K pte 0xffffffff84400000-0xffffffffa0000000 444M pmd
So remove some range before rodata with RW+x.
-v4: adapt it to all_end change.
--- arch/x86/mm/init_64.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+)
arch/x86/mm/init_64.c +62 -0
@@ -1101,6 +1101,61 @@ void __init mem_init(void) }#ifdef CONFIG_DEBUG_RODATA +static void remove_highmap_2m (unsigned long addr) +{ +pgd_t *pgd =pgd_offset_k (addr); +pud_t *pud = (pud_t *)pgd_page_vaddr (*pgd) +pud_index (addr); +pmd_t *pmd = (pmd_t *)pud_page_vaddr (*pud) +pmd_index (addr); + +set_pmd (pmd,__pmd (0 )); +} + +static void remove_highmap_2m_partial (unsigned long addr,unsigned long end) +{ +int i; +pgd_t *pgd =pgd_offset_k (addr); +pud_t *pud = (pud_t *)pgd_page_vaddr (*pgd) +pud_index (addr); +pmd_t *pmd = (pmd_t *)pud_page_vaddr (*pud) +pmd_index (addr); +pte_t *pte = (pte_t *)pmd_page_vaddr (*pmd) +pte_index (addr); + +for (i =pte_index (addr); i <pte_index (end -1 ) +1 ; i++, pte++) +set_pte (pte,__pte (0 )); +} + +static void cleanup_highmap_late (unsigned long start,unsigned long end) +{ +unsigned long addr; +unsigned long start_2m_aligned =roundup (start,PMD_SIZE ); +unsigned long end_2m_aligned =rounddown (end,PMD_SIZE ); + + start =PFN_ALIGN (start); + end &=PAGE_MASK ; + +if (start >= end) +return ; + +if (start < start_2m_aligned) { +unsigned long tmp =min (start_2m_aligned, end); + +set_memory_4k (start, (tmp - start) >>PAGE_SHIFT ); +remove_highmap_2m_partial (start, tmp); + } + +for (addr = start_2m_aligned; addr < end_2m_aligned; addr +=PMD_SIZE ) +remove_highmap_2m (addr); + +if (start <= end_2m_aligned && end_2m_aligned < end) { +set_memory_4k (end_2m_aligned, + (end - end_2m_aligned) >>PAGE_SHIFT ); +remove_highmap_2m_partial (end_2m_aligned, end); + } + +subtract_range (pfn_highmapped,NR_RANGE , +__pa_symbol (start) >>PAGE_SHIFT , +__pa_symbol (end) >>PAGE_SHIFT ); + nr_pfn_highmapped =clean_sort_range (pfn_highmapped,NR_RANGE ); +} +const int rodata_test_data =0xC3 ;EXPORT_SYMBOL_GPL (rodata_test_data);
@@ -1149,6 +1204,7 @@ void mark_rodata_ro(void)unsigned long end = (unsigned long ) &__end_rodata_hpage_align;unsigned long text_end =PFN_ALIGN (&__stop___ex_table);unsigned long rodata_end =PFN_ALIGN (&__end_rodata); +unsigned long data_start =PFN_ALIGN (&_sdata);unsigned long all_end; printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
@@ -1172,6 +1228,12 @@ void mark_rodata_ro(void) all_end =roundup (_brk_end,PMD_SIZE );set_memory_nx (rodata_start, (all_end - rodata_start) >>PAGE_SHIFT ); +cleanup_highmap_late (text_end, rodata_start); +cleanup_highmap_late (rodata_end, data_start); +cleanup_highmap_late (PFN_ALIGN (_brk_end), all_end); +cleanup_highmap_late ((unsigned long )(&__init_begin), + (unsigned long )(&__init_end)); +rodata_test ();#ifdef CONFIG_CPA_DEBUG
Re: [PATCH 3/4] x86, 64bit: remove highmap for not needed ranges
Quoted 2 lines · Yinghai Lu
add
cleanup_highmap_lateto remove highmap for initmem, around rodata, and [_brk_end,all_end).
Sorry, title should be 3/3 instead of 3/4.
Thanks
Yinghai