Remove incorrect code supporting ELF32 on RV64 and vice-versa

This is technically possible by running an RV32 supervisor on an
RV64 machine, but the M-mode and S-mode code would need to be
compiled and linked separately.

pk/elf.c

@@ -84,15 +84,20 @@ void load_elf(const char* fn, elf_info* info)
     } \
   } while(0)
 
-  info->elf64 = IS_ELF64(eh64);
-  if (info->elf64)
+  if (IS_ELF64(eh64))
   {
+#ifndef __riscv64
+    panic("can't run 64-bit ELF on 32-bit arch");
+#endif
     Elf64_Ehdr* eh;
     Elf64_Phdr* ph;
     LOAD_ELF;
   }
   else if (IS_ELF32(eh64))
   {
+#ifdef __riscv64
+    panic("can't run 32-bit ELF on 64-bit arch");
+#endif
     Elf32_Ehdr* eh;
     Elf32_Phdr* ph;
     LOAD_ELF;

pk/init.c

@@ -16,16 +16,9 @@ int uarch_counters_enabled;
 long uarch_counters[NUM_COUNTERS];
 char* uarch_counter_names[NUM_COUNTERS];
 
-void init_tf(trapframe_t* tf, long pc, long sp, int user64)
+void init_tf(trapframe_t* tf, long pc, long sp)
 {
   memset(tf, 0, sizeof(*tf));
-#ifdef __riscv64
-  if (!user64)
-    panic("can't run 32-bit ELF on 64-bit pk");
-#else
-  if (user64)
-    panic("can't run 64-bit ELF on 32-bit pk");
-#endif
   tf->status = read_csr(sstatus);
   tf->gpr[2] = sp;
   tf->epc = pc;

pk/pk.c

@@ -66,10 +66,7 @@ void run_loaded_program(struct mainvars* args)
     } \
   } while (0)
 
-  if (current.elf64)
-    STACK_INIT(uint64_t);
-  else
-    STACK_INIT(uint32_t);
+  STACK_INIT(uintptr_t);
 
   if (current.t0) // start timer if so requested
     current.t0 = rdcycle();
@@ -92,7 +89,7 @@ void run_loaded_program(struct mainvars* args)
   }
 
   trapframe_t tf;
-  init_tf(&tf, current.entry, stack_top, current.elf64);
+  init_tf(&tf, current.entry, stack_top);
   __clear_cache(0, 0);
   write_csr(sscratch, kernel_stack_top);
   start_user(&tf);

pk/pk.h

@@ -57,7 +57,7 @@ void printk(const char* s, ...);
 void printm(const char* s, ...);
 int vsnprintf(char* out, size_t n, const char* s, va_list vl);
 int snprintf(char* out, size_t n, const char* s, ...);
-void init_tf(trapframe_t*, long pc, long sp, int user64);
+void init_tf(trapframe_t*, long pc, long sp);
 void start_user(trapframe_t* tf) __attribute__((noreturn));
 void dump_tf(trapframe_t*);
 void print_logo();
@@ -72,7 +72,6 @@ void run_loaded_program(struct mainvars*);
 void boot_other_hart();
 
 typedef struct {
-  int elf64;
   int phent;
   int phnum;
   int is_supervisor;

pk/syscall.c

@@ -10,15 +10,6 @@
 
 typedef long (*syscall_t)(long, long, long, long, long, long, long);
 
-#define long_bytes (4 + 4*current.elf64)
-#define get_long(base, i) ({ long res; \
-  if (current.elf64) res = ((long*)base)[i]; \
-  else res = ((int*)base)[i]; \
-  res; })
-#define put_long(base, i, data) ({ long res; \
-  if (current.elf64) ((long*)base)[i] = (data); \
-  else ((int*)base)[i] = (data); })
-
 #define CLOCK_FREQ 1000000000
 
 void sys_exit(int code)
@@ -363,59 +354,46 @@ uintptr_t sys_mprotect(uintptr_t addr, size_t length, int prot)
 int sys_rt_sigaction(int sig, const void* act, void* oact, size_t sssz)
 {
   if (oact)
-  {
-    size_t sz = long_bytes * 3;
-    populate_mapping(oact, sz, PROT_WRITE);
-    memset(oact, 0, sz);
-  }
+    memset(oact, 0, sizeof(long) * 3);
 
   return 0;
 }
 
-long sys_time(void* loc)
+long sys_time(long* loc)
 {
   uintptr_t t = rdcycle() / CLOCK_FREQ;
   if (loc)
-  {
-    populate_mapping(loc, long_bytes, PROT_WRITE);
-    put_long(loc, 0, t);
-  }
+    *loc = t;
   return t;
 }
 
-int sys_times(void* restrict loc)
+int sys_times(long* loc)
 {
-  populate_mapping(loc, 4*long_bytes, PROT_WRITE);
-
   uintptr_t t = rdcycle();
   kassert(CLOCK_FREQ % 1000000 == 0);
-  put_long(loc, 0, t / (CLOCK_FREQ / 1000000));
-  put_long(loc, 1, 0);
-  put_long(loc, 2, 0);
-  put_long(loc, 3, 0);
+  loc[0] = t / (CLOCK_FREQ / 1000000);
+  loc[1] = 0;
+  loc[2] = 0;
+  loc[3] = 0;
   
   return 0;
 }
 
 int sys_gettimeofday(long* loc)
 {
-  populate_mapping(loc, 2*long_bytes, PROT_WRITE);
-
   uintptr_t t = rdcycle();
-  put_long(loc, 0, t/CLOCK_FREQ);
-  put_long(loc, 1, (t % CLOCK_FREQ) / (CLOCK_FREQ / 1000000));
+  loc[0] = t / CLOCK_FREQ;
+  loc[1] = (t % CLOCK_FREQ) / (CLOCK_FREQ / 1000000);
   
   return 0;
 }
 
-ssize_t sys_writev(int fd, const void* iov, int cnt)
+ssize_t sys_writev(int fd, const long* iov, int cnt)
 {
-  populate_mapping(iov, cnt*2*long_bytes, PROT_READ);
-
   ssize_t ret = 0;
   for (int i = 0; i < cnt; i++)
   {
-    ssize_t r = sys_write(fd, (void*)get_long(iov, 2*i), get_long(iov, 2*i+1));
+    ssize_t r = sys_write(fd, (void*)iov[2*i], iov[2*i+1]);
     if (r < 0)
       return r;
     ret += r;

pk/vm.c

@@ -482,9 +482,8 @@ void supervisor_vm_init()
 
 uintptr_t pk_vm_init()
 {
-  // keep RV32 addresses positive
-  if (!current.elf64)
-    current.mmap_max = MIN(current.mmap_max, 0x80000000U);
+  // keep user addresses positive
+  current.mmap_max = MIN(current.mmap_max, (uintptr_t)INTPTR_MAX + 1);
 
   __map_kernel_range(0, 0, current.first_free_paddr, PROT_READ|PROT_WRITE|PROT_EXEC);
   __map_kernel_range(first_free_page, first_free_page, free_pages * RISCV_PGSIZE, PROT_READ|PROT_WRITE);