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| author | Quentin Carbonneaux <quentin.carbonneaux@yale.edu> | 2014-12-21 22:38:24 -0500 |
|---|---|---|
| committer | Quentin Carbonneaux <quentin.carbonneaux@yale.edu> | 2014-12-21 22:38:24 -0500 |
| commit | 046532e51df9152923f8ad3326e40ae4346a0a4e (patch) | |
| tree | afaece42139eee8d372f3931495d7c1528a0c434 /elf.ml | |
| parent | fd1bb8148eca22696607c4be5511ff47865262a6 (diff) | |
| download | roux-046532e51df9152923f8ad3326e40ae4346a0a4e.tar.gz | |
pad text in elf output function
Diffstat (limited to 'elf.ml')
| -rw-r--r-- | elf.ml | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/elf.ml b/elf.ml index 0c82a73..4221cbc 100644 --- a/elf.ml +++ b/elf.ml @@ -100,7 +100,11 @@ let barebones_elf oc text = ] in let textoff = 64 + 7 * 64 in - let dataoff = textoff + String.length text in + let txtlen, txtpad = + let l = String.length text in + let p = (l + 7) land 7 in + (l + p, p) in + let dataoff = textoff + txtlen in let bssoff = dataoff + 0 in let relaoff = bssoff + 0 in let symtoff = relaoff + 0 in @@ -114,7 +118,7 @@ let barebones_elf oc text = ; le 8 (shf_ALLOC lor shf_EXECINSTR) (* sh_flags *) ; le 8 0 (* sh_addr *) ; le 8 textoff (* sh_offset *) - ; le 8 (String.length text) (* sh_size *) + ; le 8 txtlen (* sh_size *) ; le 4 0 (* sh_link *) ; le 4 0 (* sh_info *) ; le 8 1 (* sh_addralign *) @@ -150,7 +154,7 @@ let barebones_elf oc text = ; le 8 0 (* sh_size *) ; le 4 5 (* sh_link, symtab index *) ; le 4 1 (* sh_info, text section *) - ; le 8 8 (* sh_addralign *) + ; le 8 1 (* sh_addralign *) ; le 8 0x18 (* sh_entsize *) (* .symtab *) ; le 4 symtstr (* sh_name *) @@ -161,7 +165,7 @@ let barebones_elf oc text = ; le 8 (String.length symtab) (* sh_size *) ; le 4 6 (* sh_link, strtab index *) ; le 4 1 (* sh_info, first non-local symbol *) - ; le 8 8 (* sh_addralign *) + ; le 8 1 (* sh_addralign *) ; le 8 0x18 (* sh_entsize *) (* .strtab *) ; le 4 strtstr (* sh_name *) @@ -179,7 +183,7 @@ let barebones_elf oc text = List.iter (output_string oc) [ header ; sh - ; text + ; text; String.make txtpad '\x90' ; symtab ; strtab ] @@ -190,6 +194,5 @@ let _ = let text = String.concat "" [ "\xb8\x2a\x00\x00\x00" (* mov 42, %eax *) ; "\xc3" (* retq *) - ; "\xc3\xc3" (* padding *) ] in barebones_elf oc text |