xnu-792.tar.gz

[apple/xnu.git] / bsd / kern / kern_panicinfo.c

diff --git a/bsd/kern/kern_panicinfo.c b/bsd/kern/kern_panicinfo.c
index 83f7538723b38a336fe3461f5b860e188b17a447..9ad8549f1ef5169a4e7234954b84de0e2605b026 100644 (file)
--- a/bsd/kern/kern_panicinfo.c
+++ b/bsd/kern/kern_panicinfo.c
@@ -23,210 +23,159 @@
 #include <sys/param.h>
 #include <sys/fcntl.h>
 #include <sys/malloc.h>
 #include <sys/param.h>
 #include <sys/fcntl.h>
 #include <sys/malloc.h>

-#include <sys/namei.h>

 #include <sys/proc.h>
 #include <sys/proc.h>

-#include <sys/stat.h>

 #include <sys/sysctl.h>
 #include <sys/vnode.h>
 #include <sys/vm.h>
 #include <sys/sysctl.h>
 #include <sys/vnode.h>
 #include <sys/vm.h>

+#include <sys/systm.h>

 
 

+#include <mach/mach_types.h>

 #include <mach/kern_return.h>
 #include <mach/kern_return.h>

+#include <kern/kern_types.h>
+#include <vm/vm_kern.h>

 
 

-/* prototypes not exported by osfmk. */
-extern void kmem_free(vm_map_t, vm_offset_t, vm_size_t);
-extern kern_return_t kmem_alloc_wired(vm_map_t, vm_offset_t *, vm_size_t);

 
 

+/* prototypes not exported by osfmk/console. */
+extern void panic_dialog_test( void );
+extern int  panic_dialog_set_image( const unsigned char * ptr, unsigned int size );
+extern void panic_dialog_get_image( unsigned char ** ptr, unsigned int * size );

 
 

-/* Globals */
-static off_t imagesizelimit = (4 * 4096);
+/* make the compiler happy */
+extern int sysctl_dopanicinfo(int *, u_int, user_addr_t, size_t *, user_addr_t, size_t, struct proc *);

 
 

-/* Information about the current panic image */
-static int image_bits = 32;    /* Bitdepth */

 
 

-static char *image_pathname = NULL;    /* path to it */
-static size_t image_pathlen = 0;       /* and the length of the pathname */
+#define PANIC_IMAGE_SIZE_LIMIT (32 * 4096)                             /* 128K - Maximum amount of memory consumed for the panic UI */
+#define KERN_PANICINFO_TEST    (KERN_PANICINFO_IMAGE+2)                /* Allow the panic UI to be tested by root without causing a panic */

 
 

-static vm_offset_t image_ptr = NULL; /* the image itself */
-static off_t image_size = 0; /* and the imagesize */
-
-
-__private_extern__ void
-get_panicimage(vm_offset_t *imageptr, vm_size_t *imagesize, int *imagebits)
-{
-       *imageptr = image_ptr;
-       *imagesize = image_size;
-       *imagebits = image_bits;
-}
-
-static int
-panicimage_from_file(
-       char *imname,
-       off_t sizelimit,
-       vm_offset_t *image,
-       off_t *filesize,
-       struct proc *p)
-{
-       int error = 0;
-       int error1 = 0;
-       int aresid;
-       struct nameidata nd;
-       struct vattr    vattr;
-       struct vnode * vp;
-       kern_return_t   kret;
-       struct pcred *pcred = p->p_cred;
-       struct ucred *cred = pcred->pc_ucred;
-       vm_offset_t iobuf;
-
-       /* Open the file */
-       NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, imname, p);
-       error = vn_open(&nd, FREAD, S_IRUSR);
-       if (error)
-               return (error);
-       vp = nd.ni_vp;
-       
-       if (vp->v_type != VREG) { 
-               error = EFAULT;
-               goto out;
-       }
-
-       /* get the file size */
-       error = VOP_GETATTR(vp, &vattr, cred, p);
-       if (error)
-               goto out;
-
-       /* validate the file size */
-       if (vattr.va_size > sizelimit) {
-               error = EFBIG;
-               goto out;
-       }
-
-       /* allocate kernel wired memory */
-       kret = kmem_alloc_wired(kernel_map, &iobuf,
-                               (vm_size_t)vattr.va_size);
-       if (kret != KERN_SUCCESS) {
-               switch (kret) {
-               default:
-                       error = EINVAL;
-                       break;
-               case KERN_NO_SPACE:
-               case KERN_RESOURCE_SHORTAGE:
-                       error = ENOMEM;
-                       break;
-               case KERN_PROTECTION_FAILURE:
-                       error = EPERM;
-                       break;
-               }
-               goto out;
-       }
-
-       /* read the file in the kernel buffer */
-       error = vn_rdwr(UIO_READ, vp, (caddr_t)iobuf, (int)vattr.va_size,
-                       (off_t)0, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT,
-                       cred, &aresid, p);
-       if (error) {
-               (void)kmem_free(kernel_map, iobuf, (vm_size_t)vattr.va_size);
-               goto out;
-       }
-
-       /*
-        * return the image to the caller
-        * freeing this memory is callers responsibility
-        */
-       *image = iobuf;
-       *filesize = (off_t)vattr.va_size;
-
-out:
-       VOP_UNLOCK(vp, 0, p);
-       error1 = vn_close(vp, FREAD, cred, p);
-       if (error == 0)
-               error = error1;
-       return (error);
-}
+/* Local data */
+static int image_size_limit = PANIC_IMAGE_SIZE_LIMIT;

 
 __private_extern__ int
 sysctl_dopanicinfo(name, namelen, oldp, oldlenp, newp, newlen, p)
        int *name;
        u_int namelen;
 
 __private_extern__ int
 sysctl_dopanicinfo(name, namelen, oldp, oldlenp, newp, newlen, p)
        int *name;
        u_int namelen;

-       void *oldp;
+       user_addr_t oldp;

        size_t *oldlenp;
        size_t *oldlenp;

-       void *newp;
+       user_addr_t newp;

        size_t newlen;
        struct proc *p;
 {
        int error = 0;
        size_t newlen;
        struct proc *p;
 {
        int error = 0;

-       int bitdepth = 32;      /* default is 32 bits */
-       char *imname;
+       vm_offset_t newimage = (vm_offset_t )NULL;
+       kern_return_t   kret;
+       unsigned char * prev_image_ptr;
+       unsigned int prev_image_size;
+

 
        /* all sysctl names at this level are terminal */
        if (namelen != 1)
                return (ENOTDIR);               /* overloaded */
 
 
        /* all sysctl names at this level are terminal */
        if (namelen != 1)
                return (ENOTDIR);               /* overloaded */
 

+       if ( (error = proc_suser(p)) )  /* must be super user to muck with image */
+               return (error);
+

        switch (name[0]) {
        default:
        switch (name[0]) {
        default:

-               return (EOPNOTSUPP);
+               return (ENOTSUP);
+
+       case KERN_PANICINFO_TEST:
+               
+               panic_dialog_test();
+               return (0);
+

        case KERN_PANICINFO_MAXSIZE:
        case KERN_PANICINFO_MAXSIZE:

-               if (newp != NULL && (error = suser(p->p_ucred, &p->p_acflag)))
-                       return (error);
-               error = sysctl_quad(oldp, oldlenp, newp, newlen, &imagesizelimit);
+
+               /* return the image size limits */
+
+               newlen = 0;
+               newp = USER_ADDR_NULL;
+
+               error = sysctl_int(oldp, oldlenp, newp, newlen, &image_size_limit);
+

                return (error);
 
                return (error);
 

-       case KERN_PANICINFO_IMAGE16:
-               bitdepth = 16;
-               /* and fall through */
-       case KERN_PANICINFO_IMAGE32:
-               /* allocate a buffer for the image pathname */
-               MALLOC_ZONE(imname, char *, MAXPATHLEN, M_NAMEI, M_WAITOK);
-
-               if (!newp) {
-                       bcopy(image_pathname, imname, image_pathlen);
-                       imname[image_pathlen] = '\0';
-               } else
-                       imname[0] = '\0';
-               error = sysctl_string(oldp, oldlenp, newp, newlen,
-                   imname, MAXPATHLEN);
-               if (newp && !error) {
-                       char *tmpstr, *oldstr;
-                       off_t filesize = 0;
-                       size_t len;
-                       vm_offset_t image;
-                       vm_offset_t oimage = NULL;
-                       vm_size_t osize = 0;    /* covariable: quiet compiler */
-
-                       len = strlen(imname);
-                       oldstr = image_pathname;
-
-                       error = panicimage_from_file(imname, imagesizelimit,
-                                       &image, &filesize, p);
-                       if (error)
+       case KERN_PANICINFO_IMAGE:
+
+               /* If we have a new image, allocate wired kernel memory and copy it in from user space */
+               if ( newp != USER_ADDR_NULL ) {
+
+                       /* check the length of the incoming image before allocating space for it. */
+                       if ( newlen > (size_t)image_size_limit )
+                               return (ENOMEM);
+
+                       /* allocate some kernel wired memory for the new image */
+                       kret = kmem_alloc(kernel_map, &newimage, (vm_size_t)round_page_32(newlen));
+
+                       if (kret != KERN_SUCCESS) {
+                               switch (kret) {
+                               default:
+                                       error = EINVAL;
+                                       break;
+                               case KERN_NO_SPACE:
+                               case KERN_RESOURCE_SHORTAGE:
+                                       error = ENOMEM;
+                                       break;
+                               case KERN_PROTECTION_FAILURE:
+                                       error = EPERM;
+                                       break;
+                               }
+       
+                               return (error);
+                       }
+
+                       /* copy the image in from user space */
+                       if ( (error = copyin(newp, (char *) newimage, newlen)) )

                                goto errout;
 
                                goto errout;
 

-                       /* release the old image */
-                       if (image_ptr) {
-                               oimage = image_ptr;
-                               osize = image_size;
+               } else {        /* setup to make the default image active */
+
+                       newimage = (vm_offset_t )NULL;
+                       newlen = 0;
+               }
+
+               /* get the current image location and size */
+               panic_dialog_get_image( &prev_image_ptr, &prev_image_size );
+
+               /* did the caller request a copy of the previous image ? */
+               if ( oldp != USER_ADDR_NULL ) {
+                       if ( *oldlenp < prev_image_size ) {
+                               error = ERANGE;
+                               goto errout;

                        }
 
                        }
 

-                       /* remember the new one */
-                       image_ptr = image;
-                       image_bits = bitdepth;  /* new bith depth */
-                       image_size = filesize; /* new imagesize */
+                       /* copy the image to user space or zero the size if the default image is active */
+                       if ( prev_image_ptr != NULL ) {
+                               if ( (error = copyout( prev_image_ptr, oldp, prev_image_size )) )
+                                       goto errout;

 
 

-                       if (oimage)
-                               kmem_free(kernel_map, oimage, osize);
+                               *oldlenp = prev_image_size;
+                       }
+                       else /* tell the user that the default image is active */
+                               *oldlenp = 0;
+               }

 
 

-                       /* save the new name */
-                       MALLOC(tmpstr, char *, len+1, M_TEMP, M_WAITOK);
-                       bcopy(imname, tmpstr, len);
-                       tmpstr[len] = '\0';
+               /* Make the new image active, or reactivate the default image.
+                  But, handle the special case of asking for the current image
+                  without changing the current image. 
+               */

 
 

-                       image_pathname = tmpstr;        /* new pathname */
-                       image_pathlen = len;    /* new pathname length */
+               if ( !(oldp && newp == USER_ADDR_NULL) ) {
+                       if ( (error = panic_dialog_set_image( (unsigned char *) newimage, newlen )) )
+                               goto errout;

 
 

-                       /* free the old name */
-                       FREE(oldstr, M_TEMP);
+                       /* free the wired memory used by the previous image */
+                       if ( prev_image_ptr != NULL ) {
+                               (void)kmem_free(kernel_map, (vm_offset_t) prev_image_ptr, (vm_size_t)round_page_32(prev_image_size));
+                               printf("Panic UI memory freed (%d)\n", round_page_32(prev_image_size));
+                       }

                }
                }

+
+               return (0);
+

 errout:
 errout:

-               FREE_ZONE(imname, MAXPATHLEN, M_NAMEI);
+               if ( newimage != (vm_offset_t )NULL )
+                       (void)kmem_free(kernel_map, newimage, (vm_size_t)round_page_32(newlen));
+

                return (error);
        }
 }
                return (error);
        }
 }