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| author | Joerg Roedel <jroedel@suse.de> | 2020-09-07 15:15:18 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-09-07 19:45:25 +0200 |
| commit | 8570978ea030757839747aa9944ea576708be3d4 (patch) | |
| tree | db071f7629f955938db50ff11b13dbdda406e29f /arch/x86/boot/compressed/kaslr.c | |
| parent | x86/boot/compressed/64: Always switch to own page table (diff) | |
| download | linux-8570978ea030757839747aa9944ea576708be3d4.tar.xz linux-8570978ea030757839747aa9944ea576708be3d4.zip | |
x86/boot/compressed/64: Don't pre-map memory in KASLR code
With the page-fault handler in place, he identity mapping can be built
on-demand. So remove the code which manually creates the mappings and
unexport/remove the functions used for it.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20200907131613.12703-18-joro@8bytes.org
Diffstat (limited to 'arch/x86/boot/compressed/kaslr.c')
| -rw-r--r-- | arch/x86/boot/compressed/kaslr.c | 24 |
1 files changed, 1 insertions, 23 deletions
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 82662869c4cb..b59547ce5b19 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -397,8 +397,6 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size, */ mem_avoid[MEM_AVOID_ZO_RANGE].start = input; mem_avoid[MEM_AVOID_ZO_RANGE].size = (output + init_size) - input; - add_identity_map(mem_avoid[MEM_AVOID_ZO_RANGE].start, - mem_avoid[MEM_AVOID_ZO_RANGE].size); /* Avoid initrd. */ initrd_start = (u64)boot_params->ext_ramdisk_image << 32; @@ -416,15 +414,11 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size, cmd_line_size = strnlen((char *)cmd_line, COMMAND_LINE_SIZE-1) + 1; mem_avoid[MEM_AVOID_CMDLINE].start = cmd_line; mem_avoid[MEM_AVOID_CMDLINE].size = cmd_line_size; - add_identity_map(mem_avoid[MEM_AVOID_CMDLINE].start, - mem_avoid[MEM_AVOID_CMDLINE].size); } /* Avoid boot parameters. */ mem_avoid[MEM_AVOID_BOOTPARAMS].start = (unsigned long)boot_params; mem_avoid[MEM_AVOID_BOOTPARAMS].size = sizeof(*boot_params); - add_identity_map(mem_avoid[MEM_AVOID_BOOTPARAMS].start, - mem_avoid[MEM_AVOID_BOOTPARAMS].size); /* We don't need to set a mapping for setup_data. */ @@ -433,11 +427,6 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size, /* Enumerate the immovable memory regions */ num_immovable_mem = count_immovable_mem_regions(); - -#ifdef CONFIG_X86_VERBOSE_BOOTUP - /* Make sure video RAM can be used. */ - add_identity_map(0, PMD_SIZE); -#endif } /* @@ -884,19 +873,8 @@ void choose_random_location(unsigned long input, warn("Physical KASLR disabled: no suitable memory region!"); } else { /* Update the new physical address location. */ - if (*output != random_addr) { - add_identity_map(random_addr, output_size); + if (*output != random_addr) *output = random_addr; - } - - /* - * This loads the identity mapping page table. - * This should only be done if a new physical address - * is found for the kernel, otherwise we should keep - * the old page table to make it be like the "nokaslr" - * case. - */ - finalize_identity_maps(); } |