o_cloexec; preserve leading slashes in root-level paths

src/demon/linux/demon_os_linux.c

@@ -110,7 +110,7 @@ internal int
 demon_lnx_open_memory_fd_for_pid(pid_t pid){
   Temp scratch = scratch_begin(0, 0);
   String8 memory_path = push_str8f(scratch.arena, "/proc/%i/mem", pid);
-  int result = open((char*)memory_path.str, O_RDWR);
+  int result = open((char*)memory_path.str, O_RDWR|O_CLOEXEC);
   scratch_end(scratch);
   return(result);
 }
@@ -126,7 +126,7 @@ demon_lnx_arch_from_pid(pid_t pid){
   // handle to exe
   int exe_fd = -1;
   if (exe_path.size != 0){
-    exe_fd = open((char*)exe_path.str, O_RDONLY);
+    exe_fd = open((char*)exe_path.str, O_RDONLY|O_CLOEXEC);
   }
   
   // elf identification
@@ -199,7 +199,7 @@ demon_lnx_aux_from_pid(pid_t pid, Arch arch){
   // open aux data
   Temp scratch = scratch_begin(0, 0);
   String8 auxv_symbol_path = push_str8f(scratch.arena, "/proc/%d/auxv", pid);
-  int aux_fd = open((char*)auxv_symbol_path.str, O_RDONLY);
+  int aux_fd = open((char*)auxv_symbol_path.str, O_RDONLY|O_CLOEXEC);
   
   // scan aux data
   if (aux_fd >= 0){
@@ -670,7 +670,7 @@ internal int
 demon_lnx_open_maps(pid_t pid){
   Temp scratch = scratch_begin(0, 0);
   String8 path = push_str8f(scratch.arena, "/proc/%d/maps", pid);
-  int maps = open((char*)path.str, O_RDONLY);
+  int maps = open((char*)path.str, O_RDONLY|O_CLOEXEC);
   scratch_end(scratch);
   return(maps);
 }

src/lib_rdi_make/rdi_make.c

@@ -1977,12 +1977,26 @@ rdim_bake_path_tree_insert(RDIM_Arena *arena, RDIM_BakePathTree *tree, RDIM_Stri
   RDI_U8 *opl = string.str + string.size;
   for(;ptr < opl;)
   {
-    // rjf: skip past slashes
-    for(;ptr < opl && (*ptr == '/' || *ptr == '\\'); ptr += 1);
+    // rjf: skip past non-leading slashes
+    RDI_U32 leading_slash = 0;
+    if(ptr > string.str)
+    {
+      for(;ptr < opl && (*ptr == '/' || *ptr == '\\'); ptr += 1);
+    }
+    else if(ptr < opl)
+    {
+      leading_slash = (*ptr == '/');
+    }
     
-    // rjf: save beginning of non-slash range
+    // rjf: save beginning of path part
     RDI_U8 *range_first = ptr;
     
+    // rjf: advance past leading slash
+    if(leading_slash)
+    {
+      ptr += 1;
+    }
+    
     // rjf: skip past non-slashes
     for(;ptr < opl && !(*ptr == '/' || *ptr == '\\'); ptr += 1);
     

src/os/core/linux/os_core_linux.c

@@ -284,6 +284,7 @@ os_file_open(OS_AccessFlags flags, String8 path)
   {
     lnx_flags |= O_CREAT;
   }
+  lnx_flags |= O_CLOEXEC;
   int fd = open((char *)path_copy.str, lnx_flags, 0755);
   OS_Handle handle = {0};
   if(fd != -1)
@@ -652,7 +653,7 @@ os_shared_memory_alloc(U64 size, String8 name)
 {
   Temp scratch = scratch_begin(0, 0);
   String8 name_copy = push_str8_copy(scratch.arena, name);
-  int id = shm_open((char *)name_copy.str, O_RDWR | O_CREAT, 0666);
+  int id = shm_open((char *)name_copy.str, O_RDWR|O_CREAT, 0666);
   ftruncate(id, size);
   OS_Handle result = {(U64)id};
   scratch_end(scratch);