Merge pull request #1350 from fwsGonzo/dev

Enable stack sampling, update acorn

Author: fwsGonzo

api/util/statman.hpp

@@ -127,6 +127,8 @@ class Statman {
   Stat& create(const Stat::Stat_type type, const std::string& name);
   // retrieve stat based on address from stats counter: &stat.get_xxx()
   Stat& get(const void* addr);
+  // if you know the name of a statistic already
+  Stat& get_by_name(const char* name);
   // free/delete stat based on address from stats counter
   void free(void* addr);
 

cmake/library.cmake

@@ -37,7 +37,7 @@ include(${CMAKE_CURRENT_LIST_DIR}/settings.cmake)
 # Various global defines
 # * OS_TERMINATE_ON_CONTRACT_VIOLATION provides classic assert-like output from Expects / Ensures
 # * _GNU_SOURCE enables POSIX-extensions in newlib, such as strnlen. ("everything newlib has", ref. cdefs.h)
-set(CAPABS "${CAPABS} -fstack-protector-strong -DOS_TERMINATE_ON_CONTRACT_VIOLATION -D_GNU_SOURCE")
+set(CAPABS "${CAPABS} -mno-red-zone -fstack-protector-strong -DOS_TERMINATE_ON_CONTRACT_VIOLATION -D_GNU_SOURCE")
 set(WARNS  "-Wall -Wextra") #-pedantic
 
 # configure options

examples/acorn/service.cpp

@@ -15,8 +15,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include <sstream>
-
 #include <os>
 #include <acorn>
 
@@ -123,7 +121,7 @@ void Service::start()
       dashboard_ = std::make_unique<dashboard::Dashboard>(8192);
       // Add singleton component
       dashboard_->add(dashboard::Memmap::instance());
-      //dashboard_->add(dashboard::StackSampler::instance());
+      dashboard_->add(dashboard::StackSampler::instance());
       dashboard_->add(dashboard::Status::instance());
       // Construct component
       dashboard_->construct<dashboard::Statman>(Statman::get());

src/arch/x86_64/CMakeLists.txt

@@ -2,7 +2,6 @@ set(CMAKE_ASM_NASM_OBJECT_FORMAT elf64)
 
 ### x86_64 arch specific ###
 set(ARCH_OBJECTS
-  profile_intr.asm
   apic_asm.asm
   arch_start.asm
   interrupts.asm

src/arch/x86_64/interrupts.asm

@@ -18,16 +18,19 @@
 global unused_interrupt_handler:function
 global modern_interrupt_handler:function
 global cpu_sampling_irq_entry:function
+global parasite_interrupt_handler:function
+global __stack_storage_area
 
 extern current_eoi_mechanism
 extern current_intr_handler
 extern cpu_sampling_irq_handler
+extern profiler_stack_sampler
 
 SECTION .bss
 ALIGN 16
-xsave_storage_area: resb  512
+__xsave_storage_area: resb  512
 ALIGN 16
-stack_storage_area: resb  512
+__stack_storage_area: resb  512
 
 %macro PUSHAQ 0
    push rax
@@ -46,11 +49,11 @@ stack_storage_area: resb  512
    push r15
 
    ; Preserve extended state
-   fxsave [xsave_storage_area]
+   ;fxsave [__xsave_storage_area]
 %endmacro
 %macro POPAQ 0
    ; Restore extended state
-   fxrstor [xsave_storage_area]
+   ;fxrstor [__xsave_storage_area]
 
    pop r15
    pop r14
@@ -70,7 +73,7 @@ stack_storage_area: resb  512
 
 %macro SPSAVE 0
     mov  rax, rsp
-    mov  rsp, stack_storage_area+512-16
+    mov  rsp, __stack_storage_area+512-16
     push rax ;; save old RSP
     push rbp
 %endmacro
@@ -111,3 +114,15 @@ cpu_sampling_irq_entry:
   POPAQ
   sti
   iretq
+
+parasite_interrupt_handler:
+  cli
+  PUSHAQ
+  mov  rdi, QWORD [rsp + 8*14]
+  SPSAVE
+  call profiler_stack_sampler
+  call QWORD [current_intr_handler]
+  SPRSTOR
+  POPAQ
+  sti
+  iretq

src/arch/x86_64/profile_intr.asm

@@ -58,9 +58,10 @@ extern profiler_stack_sampler
 parasite_interrupt_handler:
   cli
   PUSHAQ
-  push QWORD [rsp + 32]
+  mov  rax, rsp
+  push rsp
+  mov  rsi, QWORD [rsp + 32]
   call profiler_stack_sampler
-  pop  rax
   call QWORD [current_intr_handler]
   POPAQ
   sti

src/platform/x86_pc/pit.cpp

@@ -81,16 +81,18 @@ namespace x86
 
   void PIT::oneshot(milliseconds timeval, timeout_handler handler)
   {
-    if (get().current_mode_ != RATE_GEN) {
+    if (get().current_mode_ != RATE_GEN)
       get().set_mode(RATE_GEN);
-    }
-
     if (get().current_freq_divider_ != MILLISEC_INTERVAL)
       get().set_freq_divider(MILLISEC_INTERVAL);
 
-    get().expiration = now() + timeval;
-    get().handler    = handler;
-    get().run_forever = timeval == milliseconds::zero();
+    bool forever = timeval == milliseconds::zero();
+    if (forever) {
+      get().forev_handler = handler;
+    } else {
+      get().expiration    = now() + timeval;
+      get().handler       = handler;
+    }
   }
 
   void PIT::forever(timeout_handler handler)
@@ -113,17 +115,20 @@ namespace x86
   {
     IRQ_counter ++;
 
-    if (now() >= this->expiration || run_forever)
+    if (now() >= this->expiration)
     {
-      // reset when not running forever
-      if (this->run_forever == false)
-      {
-        disable_regular_interrupts();
-      }
       if (this->handler) {
         this->handler();
         this->handler = nullptr;
       }
+      // stop PIT when not running forever
+      if (this->forev_handler == nullptr)
+          disable_regular_interrupts();
+    }
+    // always call forever handler, if set
+    if (this->forev_handler)
+    {
+      this->forev_handler();
     }
   }
 

src/platform/x86_pc/pit.hpp

@@ -43,6 +43,7 @@ namespace x86
         @param handler: A delegate or function to be called on timeout.   */
     static void oneshot(std::chrono::milliseconds ms, timeout_handler handler);
 
+    /** Run a custom handler forever */
     static void forever(timeout_handler handler);
 
     /** Stop PIT interrupts */
@@ -81,12 +82,12 @@ namespace x86
 
     // State-keeping
     uint16_t current_freq_divider_;
-    bool     run_forever;
     Mode     current_mode_;
     int64_t  IRQ_counter;
 
     // Timer handler & expiration timestamp
     timeout_handler           handler;
+    timeout_handler           forev_handler;
     std::chrono::milliseconds expiration;
 
     // Access mode bits are bits 4- and 5 in the Mode register

src/util/statman.cpp

@@ -124,6 +124,17 @@ Stat& Statman::get(const void* addr)
   throw std::out_of_range("Address out of range");
 }
 
+Stat& Statman::get_by_name(const char* name)
+{
+  for (auto* st = begin(); st < end(); st++)
+  {
+    if (st->unused() == false)
+    if (strncmp(st->name(), name, Stat::MAX_NAME_LEN) == 0)
+        return *st;
+  }
+  throw std::out_of_range("No stat found with exact given name");
+}
+
 void Statman::free(void* addr)
 {
   auto& stat = this->get(addr);