提交 ad830c74 编写于 作者: J James Morse 提交者: Zheng Zengkai

arm64: entry: Add macro for reading symbol addresses from the trampoline

stable inclusion
from stable-v5.10.105
commit 56cf5326bdf9c20de9a45e4a7a4c0ae16833e561
category: bugfix
bugzilla: 186460 https://gitee.com/src-openeuler/kernel/issues/I53MHA
CVE: CVE-2022-23960

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=56cf5326bdf9

--------------------------------

commit b28a8eeb upstream.

The trampoline code needs to use the address of symbols in the wider
kernel, e.g. vectors. PC-relative addressing wouldn't work as the
trampoline code doesn't run at the address the linker expected.

tramp_ventry uses a literal pool, unless CONFIG_RANDOMIZE_BASE is
set, in which case it uses the data page as a literal pool because
the data page can be unmapped when running in user-space, which is
required for CPUs vulnerable to meltdown.

Pull this logic out as a macro, instead of adding a third copy
of it.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NJames Morse <james.morse@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jiahao <chenjiahao16@huawei.com>
Reviewed-by: NLiao Chang <liaochang1@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
上级 0da60762
......@@ -804,6 +804,15 @@ alternative_else_nop_endif
sub \dst, \dst, PAGE_SIZE
.endm
.macro tramp_data_read_var dst, var
#ifdef CONFIG_RANDOMIZE_BASE
tramp_data_page \dst
add \dst, \dst, #:lo12:__entry_tramp_data_\var
ldr \dst, [\dst]
#else
ldr \dst, =\var
#endif
.endm
#define BHB_MITIGATION_NONE 0
#define BHB_MITIGATION_LOOP 1
......@@ -834,13 +843,8 @@ alternative_else_nop_endif
b .
2:
tramp_map_kernel x30
#ifdef CONFIG_RANDOMIZE_BASE
tramp_data_page x30
alternative_insn isb, nop, ARM64_WORKAROUND_QCOM_FALKOR_E1003
ldr x30, [x30]
#else
ldr x30, =vectors
#endif
tramp_data_read_var x30, vectors
alternative_if_not ARM64_WORKAROUND_CAVIUM_TX2_219_PRFM
prfm plil1strm, [x30, #(1b - \vector_start)]
alternative_else_nop_endif
......@@ -923,7 +927,12 @@ SYM_CODE_END(tramp_exit_compat)
.pushsection ".rodata", "a"
.align PAGE_SHIFT
SYM_DATA_START(__entry_tramp_data_start)
__entry_tramp_data_vectors:
.quad vectors
#ifdef CONFIG_ARM_SDE_INTERFACE
__entry_tramp_data___sdei_asm_handler:
.quad __sdei_asm_handler
#endif /* CONFIG_ARM_SDE_INTERFACE */
SYM_DATA_END(__entry_tramp_data_start)
.popsection // .rodata
#endif /* CONFIG_RANDOMIZE_BASE */
......@@ -1053,13 +1062,7 @@ SYM_CODE_START(__sdei_asm_entry_trampoline)
*/
1: str x4, [x1, #(SDEI_EVENT_INTREGS + S_SDEI_TTBR1)]
#ifdef CONFIG_RANDOMIZE_BASE
tramp_data_page x4
add x4, x4, #:lo12:__sdei_asm_trampoline_next_handler
ldr x4, [x4]
#else
ldr x4, =__sdei_asm_handler
#endif
tramp_data_read_var x4, __sdei_asm_handler
br x4
SYM_CODE_END(__sdei_asm_entry_trampoline)
NOKPROBE(__sdei_asm_entry_trampoline)
......@@ -1082,13 +1085,6 @@ SYM_CODE_END(__sdei_asm_exit_trampoline)
NOKPROBE(__sdei_asm_exit_trampoline)
.ltorg
.popsection // .entry.tramp.text
#ifdef CONFIG_RANDOMIZE_BASE
.pushsection ".rodata", "a"
SYM_DATA_START(__sdei_asm_trampoline_next_handler)
.quad __sdei_asm_handler
SYM_DATA_END(__sdei_asm_trampoline_next_handler)
.popsection // .rodata
#endif /* CONFIG_RANDOMIZE_BASE */
#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
/*
......
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