Changeset f558b5f for libcfa/src/concurrency

Timestamp:

Jun 17, 2021, 1:37:55 PM (3 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

26d944c

Parents:

7e1cb79

Message:

Implemented kernel_getcpu from rseq and librseq.

Location:

libcfa/src/concurrency

Files:

• kernel/startup.cfa (modified) (8 diffs)
• kernel_private.hfa (modified) (3 diffs)

libcfa/src/concurrency/kernel/startup.cfa

@@ -19 +19 @@
 // C Includes
 #include <errno.h>              // errno
+#include <signal.h>
 #include <string.h>             // strerror
 #include <unistd.h>             // sysconf
+
 extern "C" {
       #include <limits.h>       // PTHREAD_STACK_MIN
+        #include <unistd.h>       // syscall
         #include <sys/eventfd.h>  // eventfd
       #include <sys/mman.h>     // mprotect
       #include <sys/resource.h> // getrlimit
+        #include <sys/syscall.h>  // __NR_xxx
 }
 
@@ -98 +102 @@
 extern void __wake_proc(processor *);
 
+#if   defined(CFA_HAVE_LINUX_LIBRSEQ)
+        // No forward declaration needed
+        #define __kernel_rseq_register rseq_register_current_thread
+        #define __kernel_rseq_unregister rseq_unregister_current_thread
+#elif defined(CFA_HAVE_LINUX_RSEQ_H)
+        void __kernel_raw_rseq_register  (void);
+        void __kernel_raw_rseq_unregister(void);
+
+        #define __kernel_rseq_register __kernel_raw_rseq_register
+        #define __kernel_rseq_unregister __kernel_raw_rseq_unregister
+#else
+        // No forward declaration needed
+        // No initialization needed
+        static inline void noop(void) {};
+
+        #define __kernel_rseq_register noop
+        #define __kernel_rseq_unregister noop
+#endif
+
 //-----------------------------------------------------------------------------
 // Kernel storage
@@ -141 +164 @@
 #elif defined(CFA_HAVE_LINUX_RSEQ_H)
         extern "Cforall" {
-                // thread_local volatile struct rseq __cfaabi_rseq;
+                __attribute__((aligned(128))) thread_local volatile struct rseq __cfaabi_rseq @= {
+                        .cpu_id : RSEQ_CPU_ID_UNINITIALIZED,
+                };
         }
 #else
@@ -230 +255 @@
 
         register_tls( mainProcessor );
+
+        __kernel_rseq_register();
 
         //initialize the global state variables
@@ -296 +323 @@
         mainProcessor->local_data = 0p;
 
+        __kernel_rseq_unregister();
+
         unregister_tls( mainProcessor );
 
@@ -347 +376 @@
         register_tls( proc );
 
-        #if defined(CFA_HAVE_LINUX_LIBRSEQ)
-                rseq_register_current_thread();
-        #endif
+        __kernel_rseq_register();
 
         // SKULLDUGGERY: We want to create a context for the processor coroutine
@@ -389 +416 @@
 
         proc->local_data = 0p;
+
+        __kernel_rseq_unregister();
 
         unregister_tls( proc );
@@ -803 +832 @@
 }
 #endif
+
+#if   defined(CFA_HAVE_LINUX_LIBRSEQ)
+        // No definition needed
+#elif defined(CFA_HAVE_LINUX_RSEQ_H)
+
+        #if defined( __x86_64 ) || defined( __i386 )
+                #define RSEQ_SIG        0x53053053
+        #elif defined( __ARM_ARCH )
+                #ifdef __ARMEB__
+                #define RSEQ_SIG    0xf3def5e7      /* udf    #24035    ; 0x5de3 (ARMv6+) */
+                #else
+                #define RSEQ_SIG    0xe7f5def3      /* udf    #24035    ; 0x5de3 */
+                #endif
+        #endif
+
+        extern void __disable_interrupts_hard();
+        extern void __enable_interrupts_hard();
+
+        void __kernel_raw_rseq_register  (void) {
+                /* paranoid */ verify( __cfaabi_rseq.cpu_id == RSEQ_CPU_ID_UNINITIALIZED );
+
+                // int ret = syscall(__NR_rseq, &__cfaabi_rseq, sizeof(struct rseq), 0, (sigset_t *)0p, _NSIG / 8);
+                int ret = syscall(__NR_rseq, &__cfaabi_rseq, sizeof(struct rseq), 0, RSEQ_SIG);
+                if(ret != 0) {
+                        int e = errno;
+                        switch(e) {
+                        case EINVAL: abort("KERNEL ERROR: rseq register invalid argument");
+                        case ENOSYS: abort("KERNEL ERROR: rseq register no supported");
+                        case EFAULT: abort("KERNEL ERROR: rseq register with invalid argument");
+                        case EBUSY : abort("KERNEL ERROR: rseq register already registered");
+                        case EPERM : abort("KERNEL ERROR: rseq register sig  argument  on unregistration does not match the signature received on registration");
+                        default: abort("KERNEL ERROR: rseq register unexpected return %d", e);
+                        }
+                }
+        }
+
+        void __kernel_raw_rseq_unregister(void) {
+                /* paranoid */ verify( __cfaabi_rseq.cpu_id >= 0 );
+
+                // int ret = syscall(__NR_rseq, &__cfaabi_rseq, sizeof(struct rseq), RSEQ_FLAG_UNREGISTER, (sigset_t *)0p, _NSIG / 8);
+                int ret = syscall(__NR_rseq, &__cfaabi_rseq, sizeof(struct rseq), RSEQ_FLAG_UNREGISTER, RSEQ_SIG);
+                if(ret != 0) {
+                        int e = errno;
+                        switch(e) {
+                        case EINVAL: abort("KERNEL ERROR: rseq unregister invalid argument");
+                        case ENOSYS: abort("KERNEL ERROR: rseq unregister no supported");
+                        case EFAULT: abort("KERNEL ERROR: rseq unregister with invalid argument");
+                        case EBUSY : abort("KERNEL ERROR: rseq unregister already registered");
+                        case EPERM : abort("KERNEL ERROR: rseq unregister sig  argument  on unregistration does not match the signature received on registration");
+                        default: abort("KERNEL ERROR: rseq unregisteunexpected return %d", e);
+                        }
+                }
+        }
+#else
+        // No definition needed
+#endif

libcfa/src/concurrency/kernel_private.hfa

@@ -30 +30 @@
         #include <rseq/rseq.h>
 #elif defined(CFA_HAVE_LINUX_RSEQ_H)
-        // #include <linux/rseq.h>
+        #include <linux/rseq.h>
 #else
         #ifndef _GNU_SOURCE
@@ -60 +60 @@
 #elif defined(CFA_HAVE_LINUX_RSEQ_H)
         extern "Cforall" {
-                // extern __attribute__((aligned(128))) thread_local volatile struct rseq __cfaabi_rseq;
+                extern __attribute__((aligned(128))) thread_local volatile struct rseq __cfaabi_rseq;
         }
 #else
@@ -69 +69 @@
         /* paranoid */ verify( ! __preemption_enabled() );
 #if   defined(CFA_HAVE_LINUX_LIBRSEQ)
-        return rseq_current_cpu_raw();
+        return rseq_current_cpu();
 #elif defined(CFA_HAVE_LINUX_RSEQ_H)
-        // return __cfaabi_rseq.cpu_id;
+        int r = __cfaabi_rseq.cpu_id;
+        /* paranoid */ verify( r >= 0 );
+        return r;
 #else
         return sched_getcpu();