"David S. Miller" wrote:
>
> J . A . Magallon writes:
> > > What platform?
>
> > Any more info ?
>
> No, I thought it might be some cache flushing issue
> on a non-x86 machine.
>
I found the problem:
I sent out the old patch :-(
Attached is the correct version of patch-copy_user_user.
-- Manfred
// $Header$ // Kernel Version: // VERSION = 2 // PATCHLEVEL = 4 // SUBLEVEL = 4 // EXTRAVERSION = -ac8 --- 2.4/kernel/ptrace.c Sat Mar 31 21:49:29 2001 +++ build-2.4/kernel/ptrace.c Thu May 17 19:43:09 2001 @@ -19,13 +19,14 @@ /* * Access another process' address space, one page at a time. */ -static int access_one_page(struct mm_struct * mm, struct vm_area_struct * vma, unsigned long addr, void *buf, int len, int write) +static int access_one_page(struct mm_struct * mm, struct vm_area_struct * vma, unsigned long addr, void *buf, size_t len, int write) { pgd_t * pgdir; pmd_t * pgmiddle; pte_t * pgtable; char *maddr; struct page *page; + int i; repeat: spin_lock(&mm->page_table_lock); @@ -50,7 +51,7 @@ if (page != ZERO_PAGE(addr) || write) { if ((!VALID_PAGE(page)) || PageReserved(page)) { spin_unlock(&mm->page_table_lock); - return 0; + return OTHER_EFAULT; } } get_page(page); @@ -59,38 +60,40 @@ if (write) { maddr = kmap(page); - memcpy(maddr + (addr & ~PAGE_MASK), buf, len); + i = copy_from_user(maddr + (addr & ~PAGE_MASK), buf, len); flush_page_to_ram(page); flush_icache_page(vma, page); kunmap(page); } else { maddr = kmap(page); - memcpy(buf, maddr + (addr & ~PAGE_MASK), len); + i = copy_to_user(buf, maddr + (addr & ~PAGE_MASK), len); flush_page_to_ram(page); kunmap(page); } put_page(page); - return len; + return i ? CUR_EFAULT : 0; fault_in_page: spin_unlock(&mm->page_table_lock); /* -1: out of memory. 0 - unmapped page */ - if (handle_mm_fault(mm, vma, addr, write) > 0) + i = handle_mm_fault(mm, vma, addr, write); + if (i > 0) goto repeat; - return 0; - + if (i < 0) + return OTHER_ENOMEM; + return OTHER_EFAULT; bad_pgd: spin_unlock(&mm->page_table_lock); pgd_ERROR(*pgdir); - return 0; + return OTHER_EFAULT; bad_pmd: spin_unlock(&mm->page_table_lock); pmd_ERROR(*pgmiddle); - return 0; + return OTHER_EFAULT; } -static int access_mm(struct mm_struct *mm, struct vm_area_struct * vma, unsigned long addr, void *buf, int len, int write) +static int access_mm(struct mm_struct *mm, struct vm_area_struct * vma, unsigned long addr, void *buf, size_t len, int write, int *pcopied) { int copied = 0; @@ -102,30 +105,36 @@ if (this_len > len) this_len = len; retval = access_one_page(mm, vma, addr, buf, this_len, write); - copied += retval; - if (retval != this_len) - break; + if (retval) { + if (pcopied) + *pcopied = copied; + return retval; + } + copied += this_len; - len -= retval; + len -= this_len; if (!len) break; - addr += retval; - buf += retval; + addr += this_len; + buf += this_len; if (addr < vma->vm_end) continue; - if (!vma->vm_next) - break; - if (vma->vm_next->vm_start != vma->vm_end) - break; + if (!vma->vm_next || vma->vm_next->vm_start != vma->vm_end) { + if (pcopied) + *pcopied = copied; + return OTHER_EFAULT; + } vma = vma->vm_next; } - return copied; + if (pcopied) + *pcopied = copied; + return 0; } -int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) +int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, size_t len, int write) { int copied; struct mm_struct *mm; @@ -143,12 +152,44 @@ down_read(&mm->mmap_sem); vma = find_extend_vma(mm, addr); copied = 0; - if (vma) - copied = access_mm(mm, vma, addr, buf, len, write); + if (vma) { + mm_segment_t old; + old = get_fs(); + set_fs(KERNEL_DS); + /* silently ignore failues, perhaps the caller + * is interested in partial transfers + */ + access_mm(mm, vma, addr, buf, len, write, &copied); + set_fs(old); + } up_read(&mm->mmap_sem); mmput(mm); return copied; +} + +/* + * transfers 'len' bytes from/to from 'mm:oaddr' to/from + * 'current->mm:cbuf'. + * The caller must guarantee that mm won't go away. + * if do_write is true, then the data is written into 'mm:oaddr' + * Return 0 on success. + */ + + +int copy_user_to_user(char *cbuf, struct mm_struct *mm, unsigned long oaddr, size_t len, int do_write) +{ + struct vm_area_struct * vma; + int retval; + down_read(&mm->mmap_sem); + vma = find_extend_vma(mm, oaddr); + if (vma) + retval = access_mm(mm, vma, oaddr, cbuf, len, do_write, NULL); + else + retval = OTHER_EFAULT; + + up_read(&mm->mmap_sem); + return retval; } int ptrace_readdata(struct task_struct *tsk, unsigned long src, char *dst, int len) --- 2.4/include/linux/mm.h Sat May 12 10:03:59 2001 +++ build-2.4/include/linux/mm.h Thu May 17 19:42:38 2001 @@ -440,9 +440,15 @@ extern pte_t *FASTCALL(pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address)); extern int handle_mm_fault(struct mm_struct *mm,struct vm_area_struct *vma, unsigned long address, int write_access); extern int make_pages_present(unsigned long addr, unsigned long end); -extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write); +extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, size_t len, int write); extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char *dst, int len); extern int ptrace_writedata(struct task_struct *tsk, char * src, unsigned long dst, int len); + +#define OTHER_EFAULT 1 +#define OTHER_ENOMEM 2 +#define CUR_EFAULT 3 +extern int copy_user_to_user(char *cbuf, struct mm_struct *mm, unsigned long oaddr, size_t len, int do_write); + /* * On a two-level page table, this ends up being trivial. Thus the
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This archive was generated by hypermail 2b29 : Wed May 23 2001 - 21:00:24 EST