procfs: populate maps file with i-node numbers

This patch refines the implementation of procfs to generate maps file that contains correct file i-node numbers instead of 0s for file VMAs as shown below: 0-0 ---p 00000000 00:00 0 100000000000-100000001000 r--p 00000000 00:00 3 /libvdso.so 100000001000-100000002000 r-xp 00001000 00:00 3 /libvdso.so 100000002000-100000003000 r--p 00002000 00:00 3 /libvdso.so 100000003000-100000004000 r--p 00002000 00:00 3 /libvdso.so 100000004000-100000005000 rw-p 00003000 00:00 3 /libvdso.so 100000005000-100000007000 r--p 00000000 00:00 6 /cat 100000007000-10000000c000 r-xp 00002000 00:00 6 /cat 10000000c000-10000000e000 r--p 00007000 00:00 6 /cat 10000000f000-100000010000 r--p 00009000 00:00 6 /cat 100000010000-100000011000 rw-p 0000a000 00:00 6 /cat 200000000000-200000001000 ---p 00000000 00:00 0 200000001000-200000100000 rw-p 00000000 00:00 0 200000100000-200000101000 ---p 00000000 00:00 0 200000101000-200000200000 rw-p 00000000 00:00 0 800000000000-800000000000 ---p 00000000 00:00 0 It does so by capturing and saving the file i-node number when constructing file_vma so that it can be used when generating /proc/self/maps. Signed-off-by: Waldemar Kozaczuk <[email protected]> Message-Id: <[email protected]>
cloudius-systems · Jul 1, 2019 · 6f8d6cd · 6f8d6cd
1 parent 276aa1b
commit 6f8d6cd
Show file tree

Hide file tree

Showing 2 changed files with 11 additions and 1 deletion.
diff --git a/core/mmu.cc b/core/mmu.cc
@@ -1679,6 +1679,14 @@ file_vma::file_vma(addr_range range, unsigned perm, unsigned flags, fileref file
     if (err != 0) {
         throw make_error(err);
     }
+
+    struct stat st;
+    err = _file->stat(&st);
+    if (err != 0) {
+        throw make_error(err);
+    }
+
+    _file_inode = st.st_ino;
 }
 
 void file_vma::fault(uintptr_t addr, exception_frame *ef)
@@ -1910,7 +1918,7 @@ std::string procfs_maps()
             osv::fprintf(os, "%x-%x %c%c%c%c ", vma.start(), vma.end(), read, write, execute, priv);
             if (vma.flags() & mmap_file) {
                 const file_vma &f_vma = static_cast<file_vma&>(vma);
-                osv::fprintf(os, "%08x 00:00 0 %s\n", f_vma.offset(), f_vma.file()->f_dentry->d_path);
+                osv::fprintf(os, "%08x 00:00 %ld %s\n", f_vma.offset(), f_vma.file_inode(), f_vma.file()->f_dentry->d_path);
             } else {
                 osv::fprintf(os, "00000000 00:00 0\n");
             }

diff --git a/include/osv/mmu.hh b/include/osv/mmu.hh
@@ -93,10 +93,12 @@ public:
     virtual void fault(uintptr_t addr, exception_frame *ef) override;
     fileref file() const { return _file; }
     f_offset offset() const { return _offset; }
+    u64 file_inode() const { return _file_inode; }
 private:
     f_offset offset(uintptr_t addr);
     fileref _file;
     f_offset _offset;
+    u64 _file_inode;
 };
 
 ulong map_jvm(unsigned char* addr, size_t size, size_t align, balloon_ptr b);