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| author | Arjan van de Ven <arjan@linux.intel.com> | 2008-02-06 22:39:45 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-02-06 22:39:45 +0100 |
| commit | 984bb80d94d891592ab16d4d129b988792752c7b (patch) | |
| tree | efc22a5eb3e3cf05b056bedcbe48bbdb48b99ad8 | |
| parent | a57dae3aa4d00a000b5bac4238025438204c78b2 (diff) | |
| download | linux-984bb80d94d891592ab16d4d129b988792752c7b.tar.gz linux-984bb80d94d891592ab16d4d129b988792752c7b.tar.bz2 linux-984bb80d94d891592ab16d4d129b988792752c7b.zip | |
x86: mark the .rodata section also NX
The .rodata section shouldn't just be read-only,
but also non-executable. This is free since we've broken
up the 2MB page already anyway.
also update test_nx to check for this.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | arch/x86/kernel/test_nx.c | 2 | ||||
| -rw-r--r-- | arch/x86/mm/init_64.c | 9 |
2 files changed, 9 insertions, 2 deletions
diff --git a/arch/x86/kernel/test_nx.c b/arch/x86/kernel/test_nx.c index 36c100c323aa..10b8a6f69f84 100644 --- a/arch/x86/kernel/test_nx.c +++ b/arch/x86/kernel/test_nx.c @@ -139,7 +139,6 @@ static int test_NX(void) * Until then, don't run them to avoid too many people getting scared * by the error message */ -#if 0 #ifdef CONFIG_DEBUG_RODATA /* Test 3: Check if the .rodata section is executable */ @@ -152,6 +151,7 @@ static int test_NX(void) } #endif +#if 0 /* Test 4: Check if the .data section of a module is executable */ if (test_address(&test_data)) { printk(KERN_ERR "test_nx: .data section is executable\n"); diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 3a98d6f724ab..9b61c75a2355 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -591,10 +591,17 @@ void mark_rodata_ro(void) if (end <= start) return; - set_memory_ro(start, (end - start) >> PAGE_SHIFT); printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", (end - start) >> 10); + set_memory_ro(start, (end - start) >> PAGE_SHIFT); + + /* + * The rodata section (but not the kernel text!) should also be + * not-executable. + */ + start = ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK; + set_memory_nx(start, (end - start) >> PAGE_SHIFT); rodata_test(); |