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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-05-20 11:28:32 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-05-20 11:28:32 -0700 |
commit | 8a6bd2f40e96fb4d96749ab029c61f0df218b003 (patch) | |
tree | 33bbe31fad29d88c066f91fb577c92496f659122 /arch/x86/boot | |
parent | b9aad92236391f681083fa4045083d5b846b59e0 (diff) | |
parent | acf46020012ccbca1172e9c7aeab399c950d9212 (diff) | |
download | linux-8a6bd2f40e96fb4d96749ab029c61f0df218b003.tar.bz2 |
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"An unfortunately larger set of fixes, but a large portion is
selftests:
- Fix the missing clusterid initializaiton for x2apic cluster
management which caused boot failures due to IPIs being sent to the
wrong cluster
- Drop TX_COMPAT when a 64bit executable is exec()'ed from a compat
task
- Wrap access to __supported_pte_mask in __startup_64() where clang
compile fails due to a non PC relative access being generated.
- Two fixes for 5 level paging fallout in the decompressor:
- Handle GOT correctly for paging_prepare() and
cleanup_trampoline()
- Fix the page table handling in cleanup_trampoline() to avoid
page table corruption.
- Stop special casing protection key 0 as this is inconsistent with
the manpage and also inconsistent with the allocation map handling.
- Override the protection key wen moving away from PROT_EXEC to
prevent inaccessible memory.
- Fix and update the protection key selftests to address breakage and
to cover the above issue
- Add a MOV SS self test"
[ Part of the x86 fixes were in the earlier core pull due to dependencies ]
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
x86/mm: Drop TS_COMPAT on 64-bit exec() syscall
x86/apic/x2apic: Initialize cluster ID properly
x86/boot/compressed/64: Fix moving page table out of trampoline memory
x86/boot/compressed/64: Set up GOT for paging_prepare() and cleanup_trampoline()
x86/pkeys: Do not special case protection key 0
x86/pkeys/selftests: Add a test for pkey 0
x86/pkeys/selftests: Save off 'prot' for allocations
x86/pkeys/selftests: Fix pointer math
x86/pkeys: Override pkey when moving away from PROT_EXEC
x86/pkeys/selftests: Fix pkey exhaustion test off-by-one
x86/pkeys/selftests: Add PROT_EXEC test
x86/pkeys/selftests: Factor out "instruction page"
x86/pkeys/selftests: Allow faults on unknown keys
x86/pkeys/selftests: Avoid printf-in-signal deadlocks
x86/pkeys/selftests: Remove dead debugging code, fix dprint_in_signal
x86/pkeys/selftests: Stop using assert()
x86/pkeys/selftests: Give better unexpected fault error messages
x86/selftests: Add mov_to_ss test
x86/mpx/selftests: Adjust the self-test to fresh distros that export the MPX ABI
x86/pkeys/selftests: Adjust the self-test to fresh distros that export the pkeys ABI
...
Diffstat (limited to 'arch/x86/boot')
-rw-r--r-- | arch/x86/boot/compressed/head_64.S | 79 | ||||
-rw-r--r-- | arch/x86/boot/compressed/pgtable_64.c | 14 |
2 files changed, 69 insertions, 24 deletions
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index fca012baba19..8169e8b7a4dc 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -306,6 +306,25 @@ ENTRY(startup_64) leaq boot_stack_end(%rbx), %rsp /* + * paging_prepare() and cleanup_trampoline() below can have GOT + * references. Adjust the table with address we are running at. + * + * Zero RAX for adjust_got: the GOT was not adjusted before; + * there's no adjustment to undo. + */ + xorq %rax, %rax + + /* + * Calculate the address the binary is loaded at and use it as + * a GOT adjustment. + */ + call 1f +1: popq %rdi + subq $1b, %rdi + + call adjust_got + + /* * At this point we are in long mode with 4-level paging enabled, * but we might want to enable 5-level paging or vice versa. * @@ -370,10 +389,14 @@ trampoline_return: /* * cleanup_trampoline() would restore trampoline memory. * + * RDI is address of the page table to use instead of page table + * in trampoline memory (if required). + * * RSI holds real mode data and needs to be preserved across * this function call. */ pushq %rsi + leaq top_pgtable(%rbx), %rdi call cleanup_trampoline popq %rsi @@ -381,6 +404,21 @@ trampoline_return: pushq $0 popfq + /* + * Previously we've adjusted the GOT with address the binary was + * loaded at. Now we need to re-adjust for relocation address. + * + * Calculate the address the binary is loaded at, so that we can + * undo the previous GOT adjustment. + */ + call 1f +1: popq %rax + subq $1b, %rax + + /* The new adjustment is the relocation address */ + movq %rbx, %rdi + call adjust_got + /* * Copy the compressed kernel to the end of our buffer * where decompression in place becomes safe. @@ -482,19 +520,6 @@ relocated: rep stosq /* - * Adjust our own GOT - */ - leaq _got(%rip), %rdx - leaq _egot(%rip), %rcx -1: - cmpq %rcx, %rdx - jae 2f - addq %rbx, (%rdx) - addq $8, %rdx - jmp 1b -2: - -/* * Do the extraction, and jump to the new kernel.. */ pushq %rsi /* Save the real mode argument */ @@ -512,6 +537,27 @@ relocated: */ jmp *%rax +/* + * Adjust the global offset table + * + * RAX is the previous adjustment of the table to undo (use 0 if it's the + * first time we touch GOT). + * RDI is the new adjustment to apply. + */ +adjust_got: + /* Walk through the GOT adding the address to the entries */ + leaq _got(%rip), %rdx + leaq _egot(%rip), %rcx +1: + cmpq %rcx, %rdx + jae 2f + subq %rax, (%rdx) /* Undo previous adjustment */ + addq %rdi, (%rdx) /* Apply the new adjustment */ + addq $8, %rdx + jmp 1b +2: + ret + .code32 /* * This is the 32-bit trampoline that will be copied over to low memory. @@ -649,3 +695,10 @@ boot_stack_end: .balign 4096 pgtable: .fill BOOT_PGT_SIZE, 1, 0 + +/* + * The page table is going to be used instead of page table in the trampoline + * memory. + */ +top_pgtable: + .fill PAGE_SIZE, 1, 0 diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c index 32af1cbcd903..a362fa0b849c 100644 --- a/arch/x86/boot/compressed/pgtable_64.c +++ b/arch/x86/boot/compressed/pgtable_64.c @@ -23,14 +23,6 @@ struct paging_config { static char trampoline_save[TRAMPOLINE_32BIT_SIZE]; /* - * The page table is going to be used instead of page table in the trampoline - * memory. - * - * It must not be in BSS as BSS is cleared after cleanup_trampoline(). - */ -static char top_pgtable[PAGE_SIZE] __aligned(PAGE_SIZE) __section(.data); - -/* * Trampoline address will be printed by extract_kernel() for debugging * purposes. * @@ -134,7 +126,7 @@ out: return paging_config; } -void cleanup_trampoline(void) +void cleanup_trampoline(void *pgtable) { void *trampoline_pgtable; @@ -145,8 +137,8 @@ void cleanup_trampoline(void) * if it's there. */ if ((void *)__native_read_cr3() == trampoline_pgtable) { - memcpy(top_pgtable, trampoline_pgtable, PAGE_SIZE); - native_write_cr3((unsigned long)top_pgtable); + memcpy(pgtable, trampoline_pgtable, PAGE_SIZE); + native_write_cr3((unsigned long)pgtable); } /* Restore trampoline memory */ |