From a5bba930d802009c259e56c8d53086d96f63813b Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 30 May 2006 13:51:37 +1000 Subject: [PATCH] powerpc vdso updates This patch cleans up some locking & error handling in the ppc vdso and moves the vdso base pointer from the thread struct to the mm context where it more logically belongs. It brings the powerpc implementation closer to Ingo's new x86 one and also adds an arch_vma_name() function allowing to print [vsdo] in /proc//maps if Ingo's x86 vdso patch is also applied. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Mackerras diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index 01e3c08..22f0789 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -757,10 +757,10 @@ static int handle_rt_signal(unsigned long sig, struct k_sigaction *ka, /* Save user registers on the stack */ frame = &rt_sf->uc.uc_mcontext; - if (vdso32_rt_sigtramp && current->thread.vdso_base) { + if (vdso32_rt_sigtramp && current->mm->context.vdso_base) { if (save_user_regs(regs, frame, 0)) goto badframe; - regs->link = current->thread.vdso_base + vdso32_rt_sigtramp; + regs->link = current->mm->context.vdso_base + vdso32_rt_sigtramp; } else { if (save_user_regs(regs, frame, __NR_rt_sigreturn)) goto badframe; @@ -1029,10 +1029,10 @@ static int handle_signal(unsigned long sig, struct k_sigaction *ka, || __put_user(sig, &sc->signal)) goto badframe; - if (vdso32_sigtramp && current->thread.vdso_base) { + if (vdso32_sigtramp && current->mm->context.vdso_base) { if (save_user_regs(regs, &frame->mctx, 0)) goto badframe; - regs->link = current->thread.vdso_base + vdso32_sigtramp; + regs->link = current->mm->context.vdso_base + vdso32_sigtramp; } else { if (save_user_regs(regs, &frame->mctx, __NR_sigreturn)) goto badframe; diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index 27f65b9..23ba69c 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -394,8 +394,8 @@ static int setup_rt_frame(int signr, struct k_sigaction *ka, siginfo_t *info, current->thread.fpscr.val = 0; /* Set up to return from userspace. */ - if (vdso64_rt_sigtramp && current->thread.vdso_base) { - regs->link = current->thread.vdso_base + vdso64_rt_sigtramp; + if (vdso64_rt_sigtramp && current->mm->context.vdso_base) { + regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp; } else { err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]); if (err) diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c index 573afb6..bc3e15b 100644 --- a/arch/powerpc/kernel/vdso.c +++ b/arch/powerpc/kernel/vdso.c @@ -223,6 +223,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, struct vm_area_struct *vma; unsigned long vdso_pages; unsigned long vdso_base; + int rc; #ifdef CONFIG_PPC64 if (test_thread_flag(TIF_32BIT)) { @@ -237,20 +238,13 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, vdso_base = VDSO32_MBASE; #endif - current->thread.vdso_base = 0; + current->mm->context.vdso_base = 0; /* vDSO has a problem and was disabled, just don't "enable" it for the * process */ if (vdso_pages == 0) return 0; - - vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL); - if (vma == NULL) - return -ENOMEM; - - memset(vma, 0, sizeof(*vma)); - /* Add a page to the vdso size for the data page */ vdso_pages ++; @@ -259,17 +253,23 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, * at vdso_base which is the "natural" base for it, but we might fail * and end up putting it elsewhere. */ + down_write(&mm->mmap_sem); vdso_base = get_unmapped_area(NULL, vdso_base, vdso_pages << PAGE_SHIFT, 0, 0); - if (vdso_base & ~PAGE_MASK) { - kmem_cache_free(vm_area_cachep, vma); - return (int)vdso_base; + if (IS_ERR_VALUE(vdso_base)) { + rc = vdso_base; + goto fail_mmapsem; } - current->thread.vdso_base = vdso_base; + /* Allocate a VMA structure and fill it up */ + vma = kmem_cache_zalloc(vm_area_cachep, SLAB_KERNEL); + if (vma == NULL) { + rc = -ENOMEM; + goto fail_mmapsem; + } vma->vm_mm = mm; - vma->vm_start = current->thread.vdso_base; + vma->vm_start = vdso_base; vma->vm_end = vma->vm_start + (vdso_pages << PAGE_SHIFT); /* @@ -282,23 +282,38 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, * It's fine to use that for setting breakpoints in the vDSO code * pages though */ - vma->vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; + vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC; vma->vm_flags |= mm->def_flags; vma->vm_page_prot = protection_map[vma->vm_flags & 0x7]; vma->vm_ops = &vdso_vmops; - down_write(&mm->mmap_sem); - if (insert_vm_struct(mm, vma)) { - up_write(&mm->mmap_sem); - kmem_cache_free(vm_area_cachep, vma); - return -ENOMEM; - } + /* Insert new VMA */ + rc = insert_vm_struct(mm, vma); + if (rc) + goto fail_vma; + + /* Put vDSO base into mm struct and account for memory usage */ + current->mm->context.vdso_base = vdso_base; mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; up_write(&mm->mmap_sem); - return 0; + + fail_vma: + kmem_cache_free(vm_area_cachep, vma); + fail_mmapsem: + up_write(&mm->mmap_sem); + return rc; +} + +const char *arch_vma_name(struct vm_area_struct *vma) +{ + if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base) + return "[vdso]"; + return NULL; } + + static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname, unsigned long *size) { diff --git a/include/asm-powerpc/elf.h b/include/asm-powerpc/elf.h index 94d228f..319655c 100644 --- a/include/asm-powerpc/elf.h +++ b/include/asm-powerpc/elf.h @@ -294,7 +294,7 @@ do { \ NEW_AUX_ENT(AT_DCACHEBSIZE, dcache_bsize); \ NEW_AUX_ENT(AT_ICACHEBSIZE, icache_bsize); \ NEW_AUX_ENT(AT_UCACHEBSIZE, ucache_bsize); \ - VDSO_AUX_ENT(AT_SYSINFO_EHDR, current->thread.vdso_base) \ + VDSO_AUX_ENT(AT_SYSINFO_EHDR, current->mm->context.vdso_base) \ } while (0) /* PowerPC64 relocations defined by the ABIs */ diff --git a/include/asm-powerpc/mmu.h b/include/asm-powerpc/mmu.h index 31f7219..96e47d1 100644 --- a/include/asm-powerpc/mmu.h +++ b/include/asm-powerpc/mmu.h @@ -360,6 +360,7 @@ typedef struct { #ifdef CONFIG_HUGETLB_PAGE u16 low_htlb_areas, high_htlb_areas; #endif + unsigned long vdso_base; } mm_context_t; diff --git a/include/asm-powerpc/page.h b/include/asm-powerpc/page.h index ae610b6..a315d0c 100644 --- a/include/asm-powerpc/page.h +++ b/include/asm-powerpc/page.h @@ -192,6 +192,9 @@ extern void copy_user_page(void *to, void *from, unsigned long vaddr, struct page *p); extern int page_is_ram(unsigned long pfn); +struct vm_area_struct; +extern const char *arch_vma_name(struct vm_area_struct *vma); + #include #endif /* __ASSEMBLY__ */ diff --git a/include/asm-powerpc/processor.h b/include/asm-powerpc/processor.h index 93f83ef..d5c7ef1 100644 --- a/include/asm-powerpc/processor.h +++ b/include/asm-powerpc/processor.h @@ -153,7 +153,6 @@ struct thread_struct { unsigned long start_tb; /* Start purr when proc switched in */ unsigned long accum_tb; /* Total accumilated purr for process */ #endif - unsigned long vdso_base; /* base of the vDSO library */ unsigned long dabr; /* Data address breakpoint register */ #ifdef CONFIG_ALTIVEC /* Complete AltiVec register set */ -- cgit v0.10.2