syscall_emul: extend mmap system call to support file backed mmaps

For O3, which has a stat that counts reg reads, there is an additional
reg read per mmap() call since there's an arg we no longer ignore.
Otherwise, stats should not be affected.

2 files changed, 100 insertions, 7 deletions

diff --git a/src/arch/x86/linux/linux.cc b/src/arch/x86/linux/linux.cc
index 2eab555ce..f51bb16e7 100644
--- a/src/arch/x86/linux/linux.cc
+++ b/src/arch/x86/linux/linux.cc
@@ -37,10 +37,11 @@
  * Authors: Gabe Black
  */
 
-#include <fcntl.h>
-
 #include "arch/x86/linux/linux.hh"
 
+#include <fcntl.h>
+#include <sys/mman.h>
+
 // open(2) flags translation table
 SyscallFlagTransTable X86Linux64::openFlagTable[] = {
 #ifdef _MSC_VER
@@ -110,6 +111,34 @@ const int X86Linux64::NUM_OPEN_FLAGS =
         sizeof(X86Linux64::openFlagTable) /
         sizeof(X86Linux64::openFlagTable[0]);
 
+// mmap(2) flags translation table
+SyscallFlagTransTable X86Linux64::mmapFlagTable[] = {
+  { X86Linux64::TGT_MAP_SHARED,     MAP_SHARED },
+  { X86Linux64::TGT_MAP_PRIVATE,    MAP_PRIVATE },
+  { X86Linux64::TGT_MAP_32BIT,      MAP_32BIT},
+  { X86Linux64::TGT_MAP_ANON,       MAP_ANON },
+  { X86Linux64::TGT_MAP_DENYWRITE,  MAP_DENYWRITE },
+  { X86Linux64::TGT_MAP_EXECUTABLE, MAP_EXECUTABLE },
+  { X86Linux64::TGT_MAP_FILE,       MAP_FILE },
+  { X86Linux64::TGT_MAP_GROWSDOWN,  MAP_GROWSDOWN },
+#ifdef MAP_HUGETLB
+  { X86Linux64::TGT_MAP_HUGETLB,    MAP_HUGETLB },
+#endif
+  { X86Linux64::TGT_MAP_LOCKED,     MAP_LOCKED },
+  { X86Linux64::TGT_MAP_NONBLOCK,   MAP_NONBLOCK },
+  { X86Linux64::TGT_MAP_NORESERVE,  MAP_NORESERVE },
+  { X86Linux64::TGT_MAP_POPULATE,   MAP_POPULATE },
+#ifdef MAP_STACK
+  { X86Linux64::TGT_MAP_STACK,      MAP_STACK },
+#endif
+  { X86Linux64::TGT_MAP_ANONYMOUS,  MAP_ANONYMOUS },
+  { X86Linux64::TGT_MAP_FIXED,      MAP_FIXED },
+};
+
+const unsigned X86Linux64::NUM_MMAP_FLAGS =
+        sizeof(X86Linux64::mmapFlagTable) /
+        sizeof(X86Linux64::mmapFlagTable[0]);
+
 // open(2) flags translation table
 SyscallFlagTransTable X86Linux32::openFlagTable[] = {
 #ifdef _MSC_VER
@@ -179,3 +208,30 @@ const int X86Linux32::NUM_OPEN_FLAGS =
         sizeof(X86Linux32::openFlagTable) /
         sizeof(X86Linux32::openFlagTable[0]);
 
+// mmap(2) flags translation table
+SyscallFlagTransTable X86Linux32::mmapFlagTable[] = {
+  { X86Linux32::TGT_MAP_SHARED,     MAP_SHARED },
+  { X86Linux32::TGT_MAP_PRIVATE,    MAP_PRIVATE },
+  { X86Linux32::TGT_MAP_32BIT,      MAP_32BIT},
+  { X86Linux32::TGT_MAP_ANON,       MAP_ANON },
+  { X86Linux32::TGT_MAP_DENYWRITE,  MAP_DENYWRITE },
+  { X86Linux32::TGT_MAP_EXECUTABLE, MAP_EXECUTABLE },
+  { X86Linux32::TGT_MAP_FILE,       MAP_FILE },
+  { X86Linux32::TGT_MAP_GROWSDOWN,  MAP_GROWSDOWN },
+#ifdef MAP_HUGETLB
+  { X86Linux32::TGT_MAP_HUGETLB,    MAP_HUGETLB },
+#endif
+  { X86Linux32::TGT_MAP_LOCKED,     MAP_LOCKED },
+  { X86Linux32::TGT_MAP_NONBLOCK,   MAP_NONBLOCK },
+  { X86Linux32::TGT_MAP_NORESERVE,  MAP_NORESERVE },
+  { X86Linux32::TGT_MAP_POPULATE,   MAP_POPULATE },
+#ifdef MAP_STACK
+  { X86Linux32::TGT_MAP_STACK,      MAP_STACK },
+#endif
+  { X86Linux32::TGT_MAP_ANONYMOUS,  MAP_ANONYMOUS },
+  { X86Linux32::TGT_MAP_FIXED,      MAP_FIXED },
+};
+
+const unsigned X86Linux32::NUM_MMAP_FLAGS =
+        sizeof(X86Linux32::mmapFlagTable) /
+        sizeof(X86Linux32::mmapFlagTable[0]);
diff --git a/src/arch/x86/linux/linux.hh b/src/arch/x86/linux/linux.hh
index 854ab00a0..ce395f17d 100644
--- a/src/arch/x86/linux/linux.hh
+++ b/src/arch/x86/linux/linux.hh
@@ -126,8 +126,27 @@ class X86Linux64 : public Linux
 
     static const int NUM_OPEN_FLAGS;
 
-    static const unsigned TGT_MAP_ANONYMOUS = 0x20;
-    static const unsigned TGT_MAP_FIXED     = 0x10;
+    /// For mmap().
+    static SyscallFlagTransTable mmapFlagTable[];
+
+    static const unsigned TGT_MAP_SHARED        = 0x00001;
+    static const unsigned TGT_MAP_PRIVATE       = 0x00002;
+    static const unsigned TGT_MAP_32BIT         = 0x00040;
+    static const unsigned TGT_MAP_ANON          = 0x00020;
+    static const unsigned TGT_MAP_DENYWRITE     = 0x00800;
+    static const unsigned TGT_MAP_EXECUTABLE    = 0x01000;
+    static const unsigned TGT_MAP_FILE          = 0x00000;
+    static const unsigned TGT_MAP_GROWSDOWN     = 0x00100;
+    static const unsigned TGT_MAP_HUGETLB       = 0x40000;
+    static const unsigned TGT_MAP_LOCKED        = 0x02000;
+    static const unsigned TGT_MAP_NONBLOCK      = 0x10000;
+    static const unsigned TGT_MAP_NORESERVE     = 0x04000;
+    static const unsigned TGT_MAP_POPULATE      = 0x08000;
+    static const unsigned TGT_MAP_STACK         = 0x20000;
+    static const unsigned TGT_MAP_ANONYMOUS     = 0x00020;
+    static const unsigned TGT_MAP_FIXED         = 0x00010;
+
+    static const unsigned NUM_MMAP_FLAGS;
 
     typedef struct {
         uint64_t iov_base; // void *
@@ -147,7 +166,7 @@ class X86Linux64 : public Linux
         uint64_t totalhigh; /* Total high memory size */
         uint64_t freehigh;  /* Available high memory size */
         uint64_t mem_unit;  /* Memory unit size in bytes */
-   } tgt_sysinfo;
+    } tgt_sysinfo;
 
 };
 
@@ -236,8 +255,26 @@ class X86Linux32 : public Linux
 
     static const int NUM_OPEN_FLAGS;
 
-    static const unsigned TGT_MAP_ANONYMOUS = 0x20;
-    static const unsigned TGT_MAP_FIXED     = 0x10;
+    static SyscallFlagTransTable mmapFlagTable[];
+
+    static const unsigned TGT_MAP_SHARED        = 0x00001;
+    static const unsigned TGT_MAP_PRIVATE       = 0x00002;
+    static const unsigned TGT_MAP_32BIT         = 0x00040;
+    static const unsigned TGT_MAP_ANON          = 0x00020;
+    static const unsigned TGT_MAP_DENYWRITE     = 0x00800;
+    static const unsigned TGT_MAP_EXECUTABLE    = 0x01000;
+    static const unsigned TGT_MAP_FILE          = 0x00000;
+    static const unsigned TGT_MAP_GROWSDOWN     = 0x00100;
+    static const unsigned TGT_MAP_HUGETLB       = 0x40000;
+    static const unsigned TGT_MAP_LOCKED        = 0x02000;
+    static const unsigned TGT_MAP_NONBLOCK      = 0x10000;
+    static const unsigned TGT_MAP_NORESERVE     = 0x04000;
+    static const unsigned TGT_MAP_POPULATE      = 0x08000;
+    static const unsigned TGT_MAP_STACK         = 0x20000;
+    static const unsigned TGT_MAP_ANONYMOUS     = 0x00020;
+    static const unsigned TGT_MAP_FIXED         = 0x00010;
+
+    static const unsigned NUM_MMAP_FLAGS;
 
     typedef struct {
        int32_t  uptime;    /* Seconds since boot */