[pk,fesvr] pk now loads elfs itself

this allows it to detect 32b binaries

1 files changed, 57 insertions, 0 deletions

diff --git a/pk/elf.c b/pk/elf.c
new file mode 100644
index 0000000..51debb3
--- /dev/null
+++ b/pk/elf.c
@@ -0,0 +1,57 @@
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <elf.h>
+#include <string.h>
+#include "file.h"
+#include "pk.h"
+
+long load_elf(const char* fn, int* user64)
+{
+  sysret_t ret = file_open(fn, strlen(fn)+1, O_RDONLY, 0);
+  file_t* file = (file_t*)ret.result;
+  if(file == NULL)
+    panic("couldn't open %s!", fn);
+
+  char buf[2048]; // XXX
+  int header_size = file_read(file, buf, sizeof(buf)).result;
+  kassert(header_size >= (int)sizeof(Elf64_Ehdr));
+
+  const Elf64_Ehdr* eh64 = (const Elf64_Ehdr*)buf;
+  kassert(eh64->e_ident[0] == '\177' && eh64->e_ident[1] == 'E' &&
+          eh64->e_ident[2] == 'L'    && eh64->e_ident[3] == 'F');
+
+  #define LOAD_ELF do { \
+    eh = (typeof(eh))buf; \
+    kassert(header_size >= eh->e_phoff + eh->e_phnum*sizeof(*ph)); \
+    ph = (typeof(ph))(buf+eh->e_phoff); \
+    for(int i = 0; i < eh->e_phnum; i++, ph++) { \
+      if(ph->p_type == SHT_PROGBITS && ph->p_memsz) { \
+        kassert(file_pread(file, (char*)(long)ph->p_vaddr, ph->p_filesz, ph->p_offset).result == ph->p_filesz); \
+        memset((char*)(long)ph->p_vaddr+ph->p_filesz, 0, ph->p_memsz-ph->p_filesz); \
+      } \
+    } \
+  } while(0)
+
+  long entry;
+  if(eh64->e_ident[EI_CLASS] == ELFCLASS32)
+  {
+    Elf32_Ehdr* eh;
+    Elf32_Phdr* ph;
+    LOAD_ELF;
+    entry = eh->e_entry;
+  }
+  else
+  {
+    kassert(eh64->e_ident[EI_CLASS] == ELFCLASS64);
+    Elf64_Ehdr* eh;
+    Elf64_Phdr* ph;
+    LOAD_ELF;
+    entry = eh->e_entry;
+  }
+
+  *user64 = eh64->e_ident[EI_CLASS] == ELFCLASS64;
+
+  file_decref(file);
+
+  return entry;
+}