From 4dbf7af6442a9a882855bed0d999659ac413e3ac Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Wed, 30 Jan 2008 13:33:14 +0100 Subject: [PATCH] x86: adjust/fix LDT handling for Xen Based on patch from Jan Beulich . Don't rely on kmalloc(PAGE_SIZE) returning PAGE_SIZE aligned memory (Xen requires GDT *and* LDT to be page-aligned). Using the page allocator interface also removes the (albeit small) slab allocator overhead. The same change being done for 64-bits for consistency. Further, the Xen hypercall interface expects the LDT address to be virtual, not machine. [ Adjusted to unified ldt.c - Jeremy ] Signed-off-by: Jan Beulich Acked-by: Jeremy Fitzhardinge Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/ldt.c | 7 +++---- arch/x86/xen/enlighten.c | 9 +-------- 2 files changed, 4 insertions(+), 12 deletions(-) diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c index b8ef46270e24..8a7660c8394a 100644 --- a/arch/x86/kernel/ldt.c +++ b/arch/x86/kernel/ldt.c @@ -12,7 +12,6 @@ #include #include #include -#include #include #include @@ -40,7 +39,7 @@ static int alloc_ldt(mm_context_t *pc, int mincount, int reload) if (mincount * LDT_ENTRY_SIZE > PAGE_SIZE) newldt = vmalloc(mincount * LDT_ENTRY_SIZE); else - newldt = kmalloc(mincount * LDT_ENTRY_SIZE, GFP_KERNEL); + newldt = (void *)__get_free_page(GFP_KERNEL); if (!newldt) return -ENOMEM; @@ -78,7 +77,7 @@ static int alloc_ldt(mm_context_t *pc, int mincount, int reload) if (oldsize * LDT_ENTRY_SIZE > PAGE_SIZE) vfree(oldldt); else - kfree(oldldt); + put_page(virt_to_page(oldldt)); } return 0; } @@ -129,7 +128,7 @@ void destroy_context(struct mm_struct *mm) if (mm->context.size * LDT_ENTRY_SIZE > PAGE_SIZE) vfree(mm->context.ldt); else - kfree(mm->context.ldt); + put_page(virt_to_page(mm->context.ldt)); mm->context.size = 0; } } diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 72dd14d0685c..845b4fd94463 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -275,19 +275,12 @@ static unsigned long xen_store_tr(void) static void xen_set_ldt(const void *addr, unsigned entries) { - unsigned long linear_addr = (unsigned long)addr; struct mmuext_op *op; struct multicall_space mcs = xen_mc_entry(sizeof(*op)); op = mcs.args; op->cmd = MMUEXT_SET_LDT; - if (linear_addr) { - /* ldt my be vmalloced, use arbitrary_virt_to_machine */ - xmaddr_t maddr; - maddr = arbitrary_virt_to_machine((unsigned long)addr); - linear_addr = (unsigned long)maddr.maddr; - } - op->arg1.linear_addr = linear_addr; + op->arg1.linear_addr = (unsigned long)addr; op->arg2.nr_ents = entries; MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF); -- 2.20.1