4.9-stable review patch. If anyone has any objections, please let me know.
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From: Will Deacon will.deacon@arm.com
commit 439e70e27a51 upstream.
The identity map is mapped as both writeable and executable by the SWAPPER_MM_MMUFLAGS and this is relied upon by the kpti code to manage a synchronisation flag. Update the .pushsection flags to reflect the actual mapping attributes.
Reported-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Will Deacon will.deacon@arm.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Alex Shi alex.shi@linaro.org [v4.9 backport] Signed-off-by: Mark Rutland mark.rutland@arm.com [v4.9 backport] Tested-by: Will Deacon will.deacon@arm.com Tested-by: Greg Hackmann ghackmann@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/kernel/cpu-reset.S | 2 +- arch/arm64/kernel/head.S | 2 +- arch/arm64/kernel/sleep.S | 2 +- arch/arm64/mm/proc.S | 8 ++++---- 4 files changed, 7 insertions(+), 7 deletions(-)
--- a/arch/arm64/kernel/cpu-reset.S +++ b/arch/arm64/kernel/cpu-reset.S @@ -16,7 +16,7 @@ #include <asm/virt.h>
.text -.pushsection .idmap.text, "ax" +.pushsection .idmap.text, "awx"
/* * __cpu_soft_restart(el2_switch, entry, arg0, arg1, arg2) - Helper for --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -473,7 +473,7 @@ ENDPROC(__primary_switched) * end early head section, begin head code that is also used for * hotplug and needs to have the same protections as the text region */ - .section ".idmap.text","ax" + .section ".idmap.text","awx"
ENTRY(kimage_vaddr) .quad _text - TEXT_OFFSET --- a/arch/arm64/kernel/sleep.S +++ b/arch/arm64/kernel/sleep.S @@ -95,7 +95,7 @@ ENTRY(__cpu_suspend_enter) ret ENDPROC(__cpu_suspend_enter)
- .pushsection ".idmap.text", "ax" + .pushsection ".idmap.text", "awx" ENTRY(cpu_resume) bl el2_setup // if in EL2 drop to EL1 cleanly bl __cpu_setup --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -83,7 +83,7 @@ ENDPROC(cpu_do_suspend) * * x0: Address of context pointer */ - .pushsection ".idmap.text", "ax" + .pushsection ".idmap.text", "awx" ENTRY(cpu_do_resume) ldp x2, x3, [x0] ldp x4, x5, [x0, #16] @@ -147,7 +147,7 @@ alternative_else_nop_endif ret ENDPROC(cpu_do_switch_mm)
- .pushsection ".idmap.text", "ax" + .pushsection ".idmap.text", "awx"
.macro __idmap_cpu_set_reserved_ttbr1, tmp1, tmp2 adrp \tmp1, empty_zero_page @@ -180,7 +180,7 @@ ENDPROC(idmap_cpu_replace_ttbr1) .popsection
#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 - .pushsection ".idmap.text", "ax" + .pushsection ".idmap.text", "awx"
.macro __idmap_kpti_get_pgtable_ent, type dc cvac, cur_()\type()p // Ensure any existing dirty @@ -368,7 +368,7 @@ ENDPROC(idmap_kpti_install_ng_mappings) * Initialise the processor for turning the MMU on. Return in x0 the * value of the SCTLR_EL1 register. */ - .pushsection ".idmap.text", "ax" + .pushsection ".idmap.text", "awx" ENTRY(__cpu_setup) tlbi vmalle1 // Invalidate local TLB dsb nsh