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| author | James Morse <james.morse@arm.com> | 2022-03-31 19:33:53 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-02 12:41:10 +0200 |
| commit | 1291f9f7eb8ad19652e64869f66ba60f9f3e0ec4 (patch) | |
| tree | 90623a6e571676b74f7d94337494d2942aa10426 | |
| parent | 6932c82566e23aca000a60fd2d6e80c04140d119 (diff) | |
| download | linux-1291f9f7eb8ad19652e64869f66ba60f9f3e0ec4.tar.gz linux-1291f9f7eb8ad19652e64869f66ba60f9f3e0ec4.tar.bz2 linux-1291f9f7eb8ad19652e64869f66ba60f9f3e0ec4.zip | |
arm64: entry: Add macro for reading symbol addresses from the trampoline
commit b28a8eebe81c186fdb1a0078263b30576c8e1f42 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: Catalin Marinas <catalin.marinas@arm.com>
[ Removed SDEI for stable backport ]
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/arm64/kernel/entry.S | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index caf6f9cb8fd6..4fe25954fbb0 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -1022,6 +1022,15 @@ 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 @@ -1052,13 +1061,8 @@ 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 prfm plil1strm, [x30, #(1b - \vector_start)] msr vbar_el1, x30 isb @@ -1138,7 +1142,12 @@ END(tramp_exit_compat) .align PAGE_SHIFT .globl __entry_tramp_data_start __entry_tramp_data_start: +__entry_tramp_data_vectors: .quad vectors +#ifdef CONFIG_ARM_SDE_INTERFACE +__entry_tramp_data___sdei_asm_trampoline_next_handler: + .quad __sdei_asm_handler +#endif /* CONFIG_ARM_SDE_INTERFACE */ .popsection // .rodata #endif /* CONFIG_RANDOMIZE_BASE */ #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ |