The m_syswrap subsystem is Valgrind's model of how the kernel behaves

with respect to syscalls.  It is detailed and comprehensive but does
not offer a way to deal with minor deviations in behaviour from the
vanilla kernel sources, either due to running a hacked kernel or
running a vanilla kernel with a custom kernel module loaded.

This commit adds a flexible way to handle such cases without polluting
the vanilla handler syswrap-*.c files or their supporting vki_*.h
header files.  For each OS, a syswrap-OS-variants.c file is added,
containing wrappers for variants of OS.  A new command line flag
--kernel-variants= carries a comma separated list of variant names
that apply to the current run.  There are no other changes.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@4873

diff --git a/coregrind/Makefile.am b/coregrind/Makefile.am
index 25ff527c058d09c85b4e743e84665b5bad8c87e5..c03213697e491b626dfd35f0e403dcca45afd932 100644 (file)
--- a/coregrind/Makefile.am
+++ b/coregrind/Makefile.am
@@ -86,6 +86,7 @@ noinst_HEADERS = \
        m_syswrap/priv_types_n_macros.h \
        m_syswrap/priv_syswrap-generic.h \
        m_syswrap/priv_syswrap-linux.h \
+       m_syswrap/priv_syswrap-linux-variants.h \
        m_syswrap/priv_syswrap-main.h
 
 BUILT_SOURCES = 
@@ -150,6 +151,7 @@ libcoregrind_a_SOURCES = \
        m_syswrap/syscall-@VG_PLATFORM@.S \
        m_syswrap/syswrap-generic.c \
        m_syswrap/syswrap-@VG_OS@.c \
+       m_syswrap/syswrap-@VG_OS@-variants.c \
        m_syswrap/syswrap-@VG_PLATFORM@.c \
        m_syswrap/syswrap-main.c
 

diff --git a/coregrind/m_main.c b/coregrind/m_main.c
index 66beba32789bfc5c59f557e7f807f72fa776ea58..e71b27a6a4ac37cddd68dd44527f9e05c7e61c35 100644 (file)
--- a/coregrind/m_main.c
+++ b/coregrind/m_main.c
@@ -1099,6 +1099,8 @@ static Bool process_cmd_line_options( UInt* client_auxv, const char* toolname )
       else if (VG_CLO_STREQ(arg, "--smc-check=all"))
          VG_(clo_smc_check) = Vg_SmcAll;
 
+      else VG_STR_CLO (arg, "--kernel-variant",   VG_(clo_kernel_variant))
+
       else VG_BNUM_CLO(arg, "--vex-iropt-verbosity",
                        VG_(clo_vex_control).iropt_verbosity, 0, 10)
       else VG_BNUM_CLO(arg, "--vex-iropt-level",

diff --git a/coregrind/m_options.c b/coregrind/m_options.c
index ac917b1b0ae8475972373a2216449e4aec3a2b8e..21a723727d871967188a7c5e401dea144040b22c 100644 (file)
--- a/coregrind/m_options.c
+++ b/coregrind/m_options.c
@@ -77,6 +77,7 @@ Bool   VG_(clo_show_emwarns)   = False;
 Int    VG_(clo_max_stackframe) = 2000000;
 Bool   VG_(clo_wait_for_gdb)   = False;
 VgSmc  VG_(clo_smc_check)      = Vg_SmcStack;
+HChar* VG_(clo_kernel_variant) = NULL;
 
 
 /*--------------------------------------------------------------------*/

diff --git a/coregrind/m_syswrap/priv_syswrap-linux-variants.h b/coregrind/m_syswrap/priv_syswrap-linux-variants.h
new file mode 100644 (file)
index 0000000..2c93031
--- /dev/null
+++ b/coregrind/m_syswrap/priv_syswrap-linux-variants.h
@@ -0,0 +1,59 @@
+
+/*--------------------------------------------------------------------*/
+/*--- Linux-variant specific syscalls stuff.                       ---*/
+/*---                                         priv_syswrap-linux.h ---*/
+/*--------------------------------------------------------------------*/
+
+/*
+   This file is part of Valgrind, a dynamic binary instrumentation
+   framework.
+
+   Copyright (C) 2000-2005 Julian Seward
+      jseward@acm.org
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307, USA.
+
+   The GNU General Public License is contained in the file COPYING.
+*/
+
+#ifndef __PRIV_SYSWRAP_LINUX_VARIANTS_H
+#define __PRIV_SYSWRAP_LINUX_VARIANTS_H
+
+/* requires #include "priv_types_n_macros.h" */
+
+
+/* ---------------------------------------------------------------
+   BProc wrappers
+   ------------------------------------------------------------ */
+
+#define TId ThreadId
+#define UW  UWord
+#define SR  SysRes
+
+/* Return 0 means hand to kernel, non-0 means fail w/ that value. */
+extern Int  ML_(linux_variant_PRE_sys_bproc)( UW, UW, UW, UW, UW, UW );
+
+extern void ML_(linux_variant_POST_sys_bproc)( UW, UW, UW, UW, UW, UW );
+
+#undef TId
+#undef UW
+#undef SR
+
+#endif   // __PRIV_SYSWRAP_LINUX_VARIANTS_H
+
+/*--------------------------------------------------------------------*/
+/*--- end                            priv_syswrap-linux-variants.h ---*/
+/*--------------------------------------------------------------------*/

diff --git a/coregrind/m_syswrap/syswrap-linux-variants.c b/coregrind/m_syswrap/syswrap-linux-variants.c
new file mode 100644 (file)
index 0000000..8dc8a63
--- /dev/null
+++ b/coregrind/m_syswrap/syswrap-linux-variants.c
@@ -0,0 +1,91 @@
+
+/*--------------------------------------------------------------------*/
+/*--- Handlers for syscalls on minor variants of Linux kernels.    ---*/
+/*---                                     syswrap-linux-variants.c ---*/
+/*--------------------------------------------------------------------*/
+
+/*
+   This file is part of Valgrind, a dynamic binary instrumentation
+   framework.
+
+   Copyright (C) 2000-2005 Julian Seward
+      jseward@acm.org
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307, USA.
+
+   The GNU General Public License is contained in the file COPYING.
+*/
+
+/* The files syswrap-generic.c, syswrap-linux.c, syswrap-x86-linux.c,
+   syswrap-amd64-linux.c and syswrap-ppc32-linux.c, and associated
+   vki*.h header files, constitute Valgrind's model of how a vanilla
+   Linux kernel behaves with respect to syscalls.
+
+   On a few occasions, it is useful to run with a kernel that has some
+   (minor) extensions to the vanilla model, either due to running on a
+   hacked kernel, or using a vanilla kernel which has incorporated a
+   custom kernel module.  Rather than clutter the standard model, all
+   such variant handlers are placed in here.
+
+   Unlike the C files for the standard model, this file should also
+   contain all constants/types needed for said wrappers.  The vki*.h
+   headers should not be polluted with non-vanilla info. */
+
+
+#include "pub_core_basics.h"
+#include "pub_core_threadstate.h"
+#include "pub_core_aspacemgr.h"
+#include "pub_core_debuginfo.h"    // VG_(di_notify_*)
+#include "pub_core_transtab.h"     // VG_(discard_translations)
+#include "pub_core_debuglog.h"
+#include "pub_core_libcbase.h"
+#include "pub_core_libcassert.h"
+#include "pub_core_libcfile.h"
+#include "pub_core_libcprint.h"
+#include "pub_core_libcproc.h"
+#include "pub_core_mallocfree.h"
+#include "pub_core_tooliface.h"
+#include "pub_core_options.h"
+#include "pub_core_scheduler.h"
+#include "pub_core_signals.h"
+#include "pub_core_syscall.h"
+
+#include "priv_types_n_macros.h"
+#include "priv_syswrap-linux-variants.h"
+
+
+/* ---------------------------------------------------------------
+   BProc wrappers
+   ------------------------------------------------------------ */
+
+/* Return 0 means hand to kernel, non-0 means fail w/ that value. */
+Int ML_(linux_variant_PRE_sys_bproc)( UWord arg1, UWord arg2,
+                                      UWord arg3, UWord arg4,
+                                      UWord arg5, UWord arg6 )
+{
+   return 0;
+}
+
+void ML_(linux_variant_POST_sys_bproc)( UWord arg1, UWord arg2,
+                                        UWord arg3, UWord arg4,
+                                        UWord arg5, UWord arg6 )
+{
+}
+
+
+/*--------------------------------------------------------------------*/
+/*--- end                                 syswrap-linux-variants.c ---*/
+/*--------------------------------------------------------------------*/

diff --git a/coregrind/m_syswrap/syswrap-x86-linux.c b/coregrind/m_syswrap/syswrap-x86-linux.c
index adb7d33e1cee5f128e3fa430dba32b16c75bc018..0ce3db1fd2af03cd9676f93271ad6232e1c0e523 100644 (file)
--- a/coregrind/m_syswrap/syswrap-x86-linux.c
+++ b/coregrind/m_syswrap/syswrap-x86-linux.c
@@ -55,6 +55,7 @@
 #include "priv_types_n_macros.h"
 #include "priv_syswrap-generic.h"    /* for decls of generic wrappers */
 #include "priv_syswrap-linux.h"      /* for decls of linux-ish wrappers */
+#include "priv_syswrap-linux-variants.h" /* decls of linux variant wrappers */
 #include "priv_syswrap-main.h"
 
 #include "vki_unistd.h"              /* for the __NR_* constants */
@@ -976,6 +977,7 @@ DECL_TEMPLATE(x86_linux, sys_get_thread_area);
 DECL_TEMPLATE(x86_linux, sys_ptrace);
 DECL_TEMPLATE(x86_linux, sys_sigaction);
 DECL_TEMPLATE(x86_linux, old_select);
+DECL_TEMPLATE(x86_linux, sys_syscall223);
 
 PRE(old_select)
 {
@@ -1876,6 +1878,41 @@ POST(sys_sigaction)
       POST_MEM_WRITE( ARG3, sizeof(struct vki_old_sigaction));
 }
 
+
+/* ---------------------------------------------------------------
+   PRE/POST wrappers for x86/Linux-variant specific syscalls
+   ------------------------------------------------------------ */
+
+PRE(sys_syscall223)
+{
+   Int err;
+
+   /* 223 is used by sys_bproc.  If we're not on a declared bproc
+      variant, fail in the usual way. */
+
+   if (!VG_(strstr)(VG_(clo_kernel_variant), "bproc")) {
+      PRINT("non-existent syscall! (syscall 223)");
+      PRE_REG_READ0(long, "ni_syscall(223)");
+      SET_STATUS_Failure( VKI_ENOSYS );
+      return;
+   }
+
+   err = ML_(linux_variant_PRE_sys_bproc)( ARG1, ARG2, ARG3, 
+                                           ARG4, ARG5, ARG6 );
+   if (err) {
+      SET_STATUS_Failure( err );
+      return;
+   }
+   /* Let it go through. */
+   *flags |= SfMayBlock; /* who knows?  play safe. */
+}
+
+POST(sys_syscall223)
+{
+   ML_(linux_variant_POST_sys_bproc)( ARG1, ARG2, ARG3, 
+                                      ARG4, ARG5, ARG6 );
+}
+
 #undef PRE
 #undef POST
 
@@ -2168,7 +2205,7 @@ const SyscallTableEntry ML_(syscall_table)[] = {
    GENXY(__NR_getdents64,        sys_getdents64),     // 220
    GENXY(__NR_fcntl64,           sys_fcntl64),        // 221
    GENX_(222,                    sys_ni_syscall),     // 222
-   GENX_(223,                    sys_ni_syscall),     // 223
+   PLAXY(223,                    sys_syscall223),     // 223 // sys_bproc?
    LINX_(__NR_gettid,            sys_gettid),         // 224
 
 //zz    //   (__NR_readahead,         sys_readahead),      // 225 */(Linux?)

diff --git a/coregrind/pub_core_options.h b/coregrind/pub_core_options.h
index a2e87fe430682a1fbb5c639eb6b1c87a6c2e1791..67d8807259ec90df96bf0cfb1e013096ea53ebd2 100644 (file)
--- a/coregrind/pub_core_options.h
+++ b/coregrind/pub_core_options.h
@@ -163,8 +163,13 @@ typedef
    } 
    VgSmc;
 
+/* Describe extent to which self-modifying-code should be
+   auto-detected. */
 extern VgSmc VG_(clo_smc_check);
 
+/* String containing comma-separated names of minor kernel variants,
+   so they can be properly handled by m_syswrap. */
+extern HChar* VG_(clo_kernel_variant);
 
 #endif   // __PUB_CORE_OPTIONS_H