In accordance with "build one to throw away, you will anyway (tm)",
throw away the old signals simulation and more or less start again
from scratch. vg_signals.c is nearly a complete rewrite. In fact
this is now the third generation of the signals simulation.
The purpose of this is to properly support signals in threads -- a
nightmare combination. pthread_sigmask, pthread_kill and sigwait
are now alledged to work as POSIX requires.
In the process, throw away confusing and conceptually muddled old
implementation and replace with something which is more verbose but
conceptually cleaner, simpler and easier to argue is correct.
* When the client does sigaction/sigprocmask et al, the resulting
changes are stored verbatim in SCSS -- the Static Client Signal State.
So SCSS is the state the client believes the kernel is in.
* Every time SCSS changes, we recalculate the state the kernel
*should* be in so that our signal simulation works. This is the
SKSS -- Static Kernel Signal State. The kernel state is then
updated accordingly. By diffing the new and old SKSSs, the
number of real system calls made is minimised.
* The dynamic state of the client's signals is stored in DCSS
-- Dynamic Client Signal State. This just records which signals
are pending for which threads.
The big advantage of this scheme over the previous is that the SCSS ->
SKSS mapping is made explicit and gathered all in one place, rather
than spread out in a confusing way and done implicitly. That makes it
all lot easier to decide if the mapping, which is really the heart of
the signals simulation, is correct or not.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@271 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/vg_include.h b/vg_include.h
index d1cfca0..22e4f48 100644
--- a/vg_include.h
+++ b/vg_include.h
@@ -435,6 +435,7 @@
#define VG_USERREQ__READ_MILLISECOND_TIMER 0x3011
#define VG_USERREQ__PTHREAD_SIGMASK 0x3012
#define VG_USERREQ__SIGWAIT 0x3013
+#define VG_USERREQ__PTHREAD_KILL 0x3014
/* Cosmetic ... */
#define VG_USERREQ__GET_PTHREAD_TRACE_LEVEL 0x3101
@@ -597,9 +598,15 @@
ThreadState;
-/* Trivial range check on tid. */
+/* The thread table. */
+extern ThreadState VG_(threads)[VG_N_THREADS];
+
+/* Check that tid is in range and denotes a non-Empty thread. */
extern Bool VG_(is_valid_tid) ( ThreadId tid );
+/* Check that tid is in range. */
+extern Bool VG_(is_valid_or_empty_tid) ( ThreadId tid );
+
/* Copy the specified thread's state into VG_(baseBlock) in
preparation for running it. */
extern void VG_(load_thread_state)( ThreadId );
@@ -608,10 +615,6 @@
VG_(baseBlock) with junk, for sanity-check reasons. */
extern void VG_(save_thread_state)( ThreadId );
-/* Get the thread state block for the specified thread. */
-extern ThreadState* VG_(get_thread_state)( ThreadId );
-extern ThreadState* VG_(get_thread_state_UNCHECKED)( ThreadId );
-
/* And for the currently running one, if valid. */
extern ThreadState* VG_(get_current_thread_state) ( void );
@@ -676,6 +679,18 @@
(VG_AR_CLIENT_STACKBASE_REDZONE_SZW * VKI_BYTES_PER_WORD)
+/* Write a value to the client's %EDX (request return value register)
+ and set the shadow to indicate it is defined. */
+#define SET_EDX(zztid, zzval) \
+ do { VG_(threads)[zztid].m_edx = (zzval); \
+ VG_(threads)[zztid].sh_edx = VGM_WORD_VALID; \
+ } while (0)
+
+#define SET_EAX(zztid, zzval) \
+ do { VG_(threads)[zztid].m_eax = (zzval); \
+ VG_(threads)[zztid].sh_eax = VGM_WORD_VALID; \
+ } while (0)
+
/* ---------------------------------------------------------------------
Exports of vg_signals.c
@@ -685,12 +700,21 @@
extern Bool VG_(deliver_signals) ( void );
extern void VG_(unblock_host_signal) ( Int sigNo );
-extern void VG_(notify_signal_machinery_of_thread_exit) ( ThreadId tid );
-extern void VG_(update_sigstate_following_WaitSIG_change) ( void );
+extern void VG_(handle_SCSS_change) ( Bool force_update );
+
/* Fake system calls for signal handling. */
extern void VG_(do__NR_sigaction) ( ThreadId tid );
-extern void VG_(do__NR_sigprocmask) ( Int how, vki_ksigset_t* set );
+extern void VG_(do__NR_sigprocmask) ( ThreadId tid,
+ Int how,
+ vki_ksigset_t* set,
+ vki_ksigset_t* oldset );
+extern void VG_(do_pthread_sigmask_SCSS_upd) ( ThreadId tid,
+ Int how,
+ vki_ksigset_t* set,
+ vki_ksigset_t* oldset );
+extern void VG_(send_signal_to_thread) ( ThreadId thread,
+ Int signo );
/* Modify the current thread's state once we have detected it is
returning from a signal handler. */
@@ -699,7 +723,7 @@
/* Handy utilities to block/restore all host signals. */
extern void VG_(block_all_host_signals)
( /* OUT */ vki_ksigset_t* saved_mask );
-extern void VG_(restore_host_signals)
+extern void VG_(restore_all_host_signals)
( /* IN */ vki_ksigset_t* saved_mask );
/* ---------------------------------------------------------------------
@@ -818,27 +842,35 @@
definitions, which are different in places from those that glibc
defines. Since we're operating right at the kernel interface,
glibc's view of the world is entirely irrelevant. */
+
+/* --- Signal set ops --- */
extern Int VG_(ksigfillset)( vki_ksigset_t* set );
extern Int VG_(ksigemptyset)( vki_ksigset_t* set );
-extern Bool VG_(kisemptysigset)( vki_ksigset_t* set );
-extern Int VG_(ksigaddset)( vki_ksigset_t* set, Int signum );
-extern Int VG_(ksigprocmask)( Int how, const vki_ksigset_t* set,
- vki_ksigset_t* oldset );
-extern Int VG_(ksigaction) ( Int signum,
- const vki_ksigaction* act,
- vki_ksigaction* oldact );
-extern Int VG_(ksigismember) ( vki_ksigset_t* set, Int signum );
+extern Bool VG_(kisfullsigset)( vki_ksigset_t* set );
+extern Bool VG_(kisemptysigset)( vki_ksigset_t* set );
+
+extern Int VG_(ksigaddset)( vki_ksigset_t* set, Int signum );
+extern Int VG_(ksigdelset)( vki_ksigset_t* set, Int signum );
+extern Int VG_(ksigismember) ( vki_ksigset_t* set, Int signum );
+
extern void VG_(ksigaddset_from_set)( vki_ksigset_t* dst,
vki_ksigset_t* src );
extern void VG_(ksigdelset_from_set)( vki_ksigset_t* dst,
vki_ksigset_t* src );
+/* --- Mess with the kernel's sig state --- */
+extern Int VG_(ksigprocmask)( Int how, const vki_ksigset_t* set,
+ vki_ksigset_t* oldset );
+extern Int VG_(ksigaction) ( Int signum,
+ const vki_ksigaction* act,
+ vki_ksigaction* oldact );
extern Int VG_(ksignal)(Int signum, void (*sighandler)(Int));
extern Int VG_(ksigaltstack)( const vki_kstack_t* ss, vki_kstack_t* oss );
+extern Int VG_(kill)( Int pid, Int signo );
/* ---------------------------------------------------------------------
@@ -1525,13 +1557,14 @@
extern Bool VG_(is_kerror) ( Int res );
-#define KERNEL_DO_SYSCALL(thread_id, result_lvalue) \
- VG_(load_thread_state)(thread_id); \
- VG_(copy_baseBlock_to_m_state_static)(); \
- VG_(do_syscall)(); \
- VG_(copy_m_state_static_to_baseBlock)(); \
- VG_(save_thread_state)(thread_id); \
- result_lvalue = VG_(get_thread_state)(thread_id)->m_eax;
+#define KERNEL_DO_SYSCALL(thread_id, result_lvalue) \
+ VG_(load_thread_state)(thread_id); \
+ VG_(copy_baseBlock_to_m_state_static)(); \
+ VG_(do_syscall)(); \
+ VG_(copy_m_state_static_to_baseBlock)(); \
+ VG_(save_thread_state)(thread_id); \
+ VG_(threads)[thread_id].sh_eax = VGM_WORD_VALID; \
+ result_lvalue = VG_(threads)[thread_id].m_eax;
/* ---------------------------------------------------------------------