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| author |   James Morse <james.morse@arm.com> | 2021-11-23 18:29:25 +0000 |
|---|---|---|
| committer | James Morse <james.morse@arm.com> | 2022-02-16 13:17:30 +0000 |
| commit | bd09128d16fac3c34b80bd6a29088ac632e8ce09 (patch) | |
| tree | d4018981e47a285a3efac3eb15e2de2074592d61 /arch/arm64/kernel/entry.S | |
| parent | arm64: entry: Add macro for reading symbol addresses from the trampoline (diff) | |
| download | linux-dev-bd09128d16fac3c34b80bd6a29088ac632e8ce09.tar.xz linux-dev-bd09128d16fac3c34b80bd6a29088ac632e8ce09.zip | |
arm64: Add percpu vectors for EL1
The Spectre-BHB workaround adds a firmware call to the vectors. This
is needed on some CPUs, but not others. To avoid the unaffected CPU in
a big/little pair from making the firmware call, create per cpu vectors.
The per-cpu vectors only apply when returning from EL0.
Systems using KPTI can use the canonical 'full-fat' vectors directly at
EL1, the trampoline exit code will switch to this_cpu_vector on exit to
EL0. Systems not using KPTI should always use this_cpu_vector.
this_cpu_vector will point at a vector in tramp_vecs or
__bp_harden_el1_vectors, depending on whether KPTI is in use.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Diffstat (limited to 'arch/arm64/kernel/entry.S')
| -rw-r--r-- | arch/arm64/kernel/entry.S | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 8da732fefd8f..a62fee121138 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -38,7 +38,6 @@ .macro kernel_ventry, el:req, ht:req, regsize:req, label:req .align 7 .Lventry_start\@: -#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 .if \el == 0 /* * This must be the first instruction of the EL0 vector entries. It is @@ -53,7 +52,6 @@ .endif .Lskip_tramp_vectors_cleanup\@: .endif -#endif sub sp, sp, #PT_REGS_SIZE #ifdef CONFIG_VMAP_STACK @@ -712,10 +710,10 @@ alternative_else_nop_endif .endm .macro tramp_exit, regsize = 64 - adr x30, tramp_vectors -#ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY - add x30, x30, SZ_4K -#endif + tramp_data_read_var x30, this_cpu_vector + get_this_cpu_offset x29 + ldr x30, [x30, x29] + msr vbar_el1, x30 ldr lr, [sp, #S_LR] tramp_unmap_kernel x29 @@ -775,6 +773,8 @@ __entry_tramp_data_vectors: __entry_tramp_data___sdei_asm_handler: .quad __sdei_asm_handler #endif /* CONFIG_ARM_SDE_INTERFACE */ +__entry_tramp_data_this_cpu_vector: + .quad this_cpu_vector SYM_DATA_END(__entry_tramp_data_start) .popsection // .rodata #endif /* CONFIG_RANDOMIZE_BASE */ |