diff options
| -rw-r--r-- | ChangeLog | 8 | ||||
| -rw-r--r-- | stapfuncs.5.in | 10 | ||||
| -rw-r--r-- | tapset/context.stp | 4 | ||||
| -rw-r--r-- | tapset/conversions.stp | 28 | ||||
| -rw-r--r-- | tapsets.cxx | 44 |
5 files changed, 64 insertions, 30 deletions
@@ -1,5 +1,13 @@ 2005-09-03 Frank Ch. Eigler <fche@elastic.org> + PR 1187 prime + * tapset.cxx (literal_stmt_for_local): Don't automgaically copy + target char*'s to systemtap strings. + * tapset/conversions.stp (user_string, kernel_string): New functions. + * stapfuncs.5.in: Document new functions. + +2005-09-03 Frank Ch. Eigler <fche@elastic.org> + PR 1292, by popular request. * parse.cxx (parse_functiondecl): Allow optional value/param type declarations. diff --git a/stapfuncs.5.in b/stapfuncs.5.in index 597dc674..e4eedb94 100644 --- a/stapfuncs.5.in +++ b/stapfuncs.5.in @@ -70,6 +70,16 @@ the leading "0x". string:string (num:long) Return a decimal string representation of the given integer. +.TP +kernel_string:string (addr:long) +Copy a string from kernel space at given address. The validation of this +address is only partial at present. + +.TP +user_string:string (addr:long) +Copy a string from user space at given address. The validation of this +address is only partial at present. + .SS TIMESTAMP .TP diff --git a/tapset/context.stp b/tapset/context.stp index 32b009bf..6d600190 100644 --- a/tapset/context.stp +++ b/tapset/context.stp @@ -10,8 +10,9 @@ function print_backtrace () %{ } %} -function backtrace () %{ +function backtrace:string () %{ if (CONTEXT->regs) { + /* XXX: is String really necessary for this? */ String str = _stp_string_init (0); _stp_stack_sprint (str, CONTEXT->regs, 0); strlcpy (THIS->__retvalue, _stp_string_ptr(str), MAXSTRINGLEN); @@ -79,6 +80,7 @@ function euid:long () %{ function print_stack(stk:string) %{ char *ptr = THIS->stk; char *tok = strsep(&ptr, " "); + /* XXX: is this header really necessary & accurate? */ _stp_printf ("trace for %d (%s)\n", current->pid, current->comm); while (tok && *tok) { _stp_print_cstr(" "); diff --git a/tapset/conversions.stp b/tapset/conversions.stp index 901f26a4..50dbfeb0 100644 --- a/tapset/conversions.stp +++ b/tapset/conversions.stp @@ -6,3 +6,31 @@ function string:string (num:long) %{ sprintf (THIS->__retvalue, "%lld", (long long) THIS->num); %} + +function kernel_string:string (addr:long) %{ + char *destination = THIS->__retvalue; + deref_string (destination, THIS->addr, MAXSTRINGLEN); + goto success; +deref_fault: /* branched to from deref() */ + { + static char errmsg[40]; + snprintf (errmsg, 40, "kernel string copy fault at 0x%p", + (void *) (uintptr_t) THIS->addr); + CONTEXT->last_error = errmsg; + } +success: ; +%} + +# NB: accessing user space is hazardous from certain kernel contexts. +function user_string:string (addr:long) %{ + long rc = _stp_strncpy_from_user (THIS->__retvalue, + (const char __user*) (uintptr_t) THIS->addr, + MAXSTRINGLEN); + if (rc < 0) + { + static char errmsg[40]; + snprintf (errmsg, 40, "user string copy fault at 0x%p", + (void *) (uintptr_t) THIS->addr); + CONTEXT->last_error = errmsg; + } +%} diff --git a/tapsets.cxx b/tapsets.cxx index f2eeb5d1..14031308 100644 --- a/tapsets.cxx +++ b/tapsets.cxx @@ -957,42 +957,28 @@ dwflpp dwarf_formudata (dwarf_attr_integrate (pointee_typedie, DW_AT_encoding, &attr_mem), &pointee_encoding); - if (pointee_typetag == DW_TAG_base_type - && (pointee_encoding == DW_ATE_signed_char - || pointee_encoding == DW_ATE_unsigned_char - || ((pointee_encoding == DW_ATE_signed - || pointee_encoding == DW_ATE_unsigned) && pointee_byte_size == 1))) - { - // We have an (un)signed char* or (un)signed char[], fetch it into 'tmpc' and - // then copy to the return value via something strcpy-ish. - ty = pe_string; - prelude += "intptr_t tmpc = 0;\n"; - if (typetag == DW_TAG_array_type) - c_translate_array (&pool, 1, module_bias, typedie, &tail, NULL, 0); - else - c_translate_pointer (&pool, 1, module_bias, typedie, &tail); - c_translate_addressof (&pool, 1, module_bias, NULL, pointee_typedie, &tail, "tmpc"); - postlude += "deref_string (THIS->__retvalue, tmpc, MAXSTRINGLEN);\n"; - } + // We have the pointer: cast it to an integral type via &(*(...)) + + // NB: per bug #1187, at one point char*-like types were + // automagically converted here to systemtap string values. + // For several reasons, this was taken back out, leaving + // pointer-to-string "conversion" (copying) to tapset functions. + + ty = pe_long; + if (typetag == DW_TAG_array_type) + c_translate_array (&pool, 1, module_bias, typedie, &tail, NULL, 0); else - { - // We have some other pointer: cast it to an integral type via &(*(...)) - ty = pe_long; - if (typetag == DW_TAG_array_type) - c_translate_array (&pool, 1, module_bias, typedie, &tail, NULL, 0); - else - c_translate_pointer (&pool, 1, module_bias, typedie, &tail); - c_translate_addressof (&pool, 1, module_bias, NULL, pointee_typedie, &tail, - "THIS->__retvalue"); - } + c_translate_pointer (&pool, 1, module_bias, typedie, &tail); + c_translate_addressof (&pool, 1, module_bias, NULL, pointee_typedie, &tail, + "THIS->__retvalue"); } break; } - + size_t bufsz = 1024; char *buf = static_cast<char*>(malloc(bufsz)); assert(buf); - + FILE *memstream = open_memstream (&buf, &bufsz); assert(memstream); |