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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-14 11:57:22 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-14 11:57:22 -0800 |
commit | 10a0c0f0595b20efa127a1816670c64a3d0e4965 (patch) | |
tree | 884e10109861e4e8c05aced820c36b4f06563be9 /drivers | |
parent | dcd1bfd50ab6952e8c60fd99d065d5be38b4b8b4 (diff) | |
parent | 7030a7e9321166eef44c811fe4af4d460360d424 (diff) | |
download | linux-10a0c0f0595b20efa127a1816670c64a3d0e4965.tar.bz2 |
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Misc changes:
- fix lguest bug
- fix /proc/meminfo output on certain configs
- fix pvclock bug
- fix reboot on certain iMacs by adding new reboot quirk
- fix bootup crash
- fix FPU boot line option parsing
- add more x86 self-tests
- small cleanups, documentation improvements, etc"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu/amd: Remove an unneeded condition in srat_detect_node()
x86/vdso/pvclock: Protect STABLE check with the seqcount
x86/mm: Improve switch_mm() barrier comments
selftests/x86: Test __kernel_sigreturn and __kernel_rt_sigreturn
x86/reboot/quirks: Add iMac10,1 to pci_reboot_dmi_table[]
lguest: Map switcher text R/O
x86/boot: Hide local labels in verify_cpu()
x86/fpu: Disable AVX when eagerfpu is off
x86/fpu: Disable MPX when eagerfpu is off
x86/fpu: Disable XGETBV1 when no XSAVE
x86/fpu: Fix early FPU command-line parsing
x86/mm: Use PAGE_ALIGNED instead of IS_ALIGNED
selftests/x86: Disable the ldt_gdt_64 test for now
x86/mm/pat: Make split_page_count() check for empty levels to fix /proc/meminfo output
x86/boot: Double BOOT_HEAP_SIZE to 64KB
x86/mm: Add barriers and document switch_mm()-vs-flush synchronization
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/lguest/core.c | 74 |
1 files changed, 51 insertions, 23 deletions
diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c index 312ffd3d0017..9e385b38debf 100644 --- a/drivers/lguest/core.c +++ b/drivers/lguest/core.c @@ -22,7 +22,8 @@ unsigned long switcher_addr; struct page **lg_switcher_pages; -static struct vm_struct *switcher_vma; +static struct vm_struct *switcher_text_vma; +static struct vm_struct *switcher_stacks_vma; /* This One Big lock protects all inter-guest data structures. */ DEFINE_MUTEX(lguest_lock); @@ -83,54 +84,80 @@ static __init int map_switcher(void) } /* + * Copy in the compiled-in Switcher code (from x86/switcher_32.S). + * It goes in the first page, which we map in momentarily. + */ + memcpy(kmap(lg_switcher_pages[0]), start_switcher_text, + end_switcher_text - start_switcher_text); + kunmap(lg_switcher_pages[0]); + + /* * We place the Switcher underneath the fixmap area, which is the * highest virtual address we can get. This is important, since we * tell the Guest it can't access this memory, so we want its ceiling * as high as possible. */ - switcher_addr = FIXADDR_START - (TOTAL_SWITCHER_PAGES+1)*PAGE_SIZE; + switcher_addr = FIXADDR_START - TOTAL_SWITCHER_PAGES*PAGE_SIZE; /* - * Now we reserve the "virtual memory area" we want. We might - * not get it in theory, but in practice it's worked so far. - * The end address needs +1 because __get_vm_area allocates an - * extra guard page, so we need space for that. + * Now we reserve the "virtual memory area"s we want. We might + * not get them in theory, but in practice it's worked so far. + * + * We want the switcher text to be read-only and executable, and + * the stacks to be read-write and non-executable. */ - switcher_vma = __get_vm_area(TOTAL_SWITCHER_PAGES * PAGE_SIZE, - VM_ALLOC, switcher_addr, switcher_addr - + (TOTAL_SWITCHER_PAGES+1) * PAGE_SIZE); - if (!switcher_vma) { + switcher_text_vma = __get_vm_area(PAGE_SIZE, VM_ALLOC|VM_NO_GUARD, + switcher_addr, + switcher_addr + PAGE_SIZE); + + if (!switcher_text_vma) { err = -ENOMEM; printk("lguest: could not map switcher pages high\n"); goto free_pages; } + switcher_stacks_vma = __get_vm_area(SWITCHER_STACK_PAGES * PAGE_SIZE, + VM_ALLOC|VM_NO_GUARD, + switcher_addr + PAGE_SIZE, + switcher_addr + TOTAL_SWITCHER_PAGES * PAGE_SIZE); + if (!switcher_stacks_vma) { + err = -ENOMEM; + printk("lguest: could not map switcher pages high\n"); + goto free_text_vma; + } + /* * This code actually sets up the pages we've allocated to appear at * switcher_addr. map_vm_area() takes the vma we allocated above, the - * kind of pages we're mapping (kernel pages), and a pointer to our - * array of struct pages. + * kind of pages we're mapping (kernel text pages and kernel writable + * pages respectively), and a pointer to our array of struct pages. */ - err = map_vm_area(switcher_vma, PAGE_KERNEL_EXEC, lg_switcher_pages); + err = map_vm_area(switcher_text_vma, PAGE_KERNEL_RX, lg_switcher_pages); + if (err) { + printk("lguest: text map_vm_area failed: %i\n", err); + goto free_vmas; + } + + err = map_vm_area(switcher_stacks_vma, PAGE_KERNEL, + lg_switcher_pages + SWITCHER_TEXT_PAGES); if (err) { - printk("lguest: map_vm_area failed: %i\n", err); - goto free_vma; + printk("lguest: stacks map_vm_area failed: %i\n", err); + goto free_vmas; } /* * Now the Switcher is mapped at the right address, we can't fail! - * Copy in the compiled-in Switcher code (from x86/switcher_32.S). */ - memcpy(switcher_vma->addr, start_switcher_text, - end_switcher_text - start_switcher_text); - printk(KERN_INFO "lguest: mapped switcher at %p\n", - switcher_vma->addr); + switcher_text_vma->addr); /* And we succeeded... */ return 0; -free_vma: - vunmap(switcher_vma->addr); +free_vmas: + /* Undoes map_vm_area and __get_vm_area */ + vunmap(switcher_stacks_vma->addr); +free_text_vma: + vunmap(switcher_text_vma->addr); free_pages: i = TOTAL_SWITCHER_PAGES; free_some_pages: @@ -148,7 +175,8 @@ static void unmap_switcher(void) unsigned int i; /* vunmap() undoes *both* map_vm_area() and __get_vm_area(). */ - vunmap(switcher_vma->addr); + vunmap(switcher_text_vma->addr); + vunmap(switcher_stacks_vma->addr); /* Now we just need to free the pages we copied the switcher into */ for (i = 0; i < TOTAL_SWITCHER_PAGES; i++) __free_pages(lg_switcher_pages[i], 0); |