diff options
| author | James Morse <james.morse@arm.com> | 2022-03-15 18:24:09 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-03-19 13:40:15 +0100 |
| commit | 1bb1944970a9dc2d05160e014a2aac634b0eca48 (patch) | |
| tree | bedc664db3e8dd1bd82504998227de206d0d4442 /arch/arm64 | |
| parent | 3abf6e8a7aa0fad437481d27ba0a249b9f22f131 (diff) | |
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>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kernel/entry.S | 35 |
1 files changed, 16 insertions, 19 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 14351ee5e812..e4b5a15c2e2e 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -1063,6 +1063,15 @@ 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 @@ -1093,13 +1102,8 @@ 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 @@ -1183,7 +1187,12 @@ 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 */ @@ -1310,13 +1319,7 @@ ENTRY(__sdei_asm_entry_trampoline) */ 1: str x4, [x1, #(SDEI_EVENT_INTREGS + S_ORIG_ADDR_LIMIT)] -#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_trampoline_next_handler br x4 ENDPROC(__sdei_asm_entry_trampoline) NOKPROBE(__sdei_asm_entry_trampoline) @@ -1339,12 +1342,6 @@ ENDPROC(__sdei_asm_exit_trampoline) NOKPROBE(__sdei_asm_exit_trampoline) .ltorg .popsection // .entry.tramp.text -#ifdef CONFIG_RANDOMIZE_BASE -.pushsection ".rodata", "a" -__sdei_asm_trampoline_next_handler: - .quad __sdei_asm_handler -.popsection // .rodata -#endif /* CONFIG_RANDOMIZE_BASE */ #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ /* |