Revert "x86/mm/ASLR: Propagate base load address calculation"

This reverts commit:

  f47233c2d3 ("x86/mm/ASLR: Propagate base load address calculation")

The main reason for the revert is that the new boot flag does not work
at all currently, and in order to make this work, we need non-trivial
changes to the x86 boot code which we didn't manage to get done in
time for merging.

And even if we did, they would've been too risky so instead of
rushing things and break booting 4.1 on boxes left and right, we
will be very strict and conservative and will take our time with
this to fix and test it properly.

Reported-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: H. Peter Anvin <hpa@linux.intel.com
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Junjie Mao <eternal.n08@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/20150316100628.GD22995@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Borislav Petkov
2015-03-16 11:06:28 +01:00
committed by Ingo Molnar
parent f4c3686386
commit 69797dafe3
7 changed files with 17 additions and 61 deletions

View File

@@ -14,13 +14,6 @@
static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@"
LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION;
struct kaslr_setup_data {
__u64 next;
__u32 type;
__u32 len;
__u8 data[1];
} kaslr_setup_data;
#define I8254_PORT_CONTROL 0x43
#define I8254_PORT_COUNTER0 0x40
#define I8254_CMD_READBACK 0xC0
@@ -302,29 +295,7 @@ static unsigned long find_random_addr(unsigned long minimum,
return slots_fetch_random();
}
static void add_kaslr_setup_data(struct boot_params *params, __u8 enabled)
{
struct setup_data *data;
kaslr_setup_data.type = SETUP_KASLR;
kaslr_setup_data.len = 1;
kaslr_setup_data.next = 0;
kaslr_setup_data.data[0] = enabled;
data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
while (data && data->next)
data = (struct setup_data *)(unsigned long)data->next;
if (data)
data->next = (unsigned long)&kaslr_setup_data;
else
params->hdr.setup_data = (unsigned long)&kaslr_setup_data;
}
unsigned char *choose_kernel_location(struct boot_params *params,
unsigned char *input,
unsigned char *choose_kernel_location(unsigned char *input,
unsigned long input_size,
unsigned char *output,
unsigned long output_size)
@@ -335,17 +306,14 @@ unsigned char *choose_kernel_location(struct boot_params *params,
#ifdef CONFIG_HIBERNATION
if (!cmdline_find_option_bool("kaslr")) {
debug_putstr("KASLR disabled by default...\n");
add_kaslr_setup_data(params, 0);
goto out;
}
#else
if (cmdline_find_option_bool("nokaslr")) {
debug_putstr("KASLR disabled by cmdline...\n");
add_kaslr_setup_data(params, 0);
goto out;
}
#endif
add_kaslr_setup_data(params, 1);
/* Record the various known unsafe memory ranges. */
mem_avoid_init((unsigned long)input, input_size,