[PATCH v5 19/33] arm64: Annotate unwind_hint for symbols with empty stack
From: Chen Zhongjin <hidden>
Date: 2022-06-22 15:56:19
Also in:
linux-arch, linux-arm-kernel, linux-kbuild, live-patching, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
Some assembly symbols contain code that might be executed with an unspecified stack state (e.g. invalid stack pointer, no stackframe, code after alt_cb, ...). Annotate those symbol with UNWIND_HINT_EMPTY to let objtool be aware of them. Signed-off-by: Julien Thierry <redacted> Signed-off-by: Chen Zhongjin <redacted> --- arch/arm64/include/asm/assembler.h | 2 ++ arch/arm64/kernel/cpu-reset.S | 2 ++ arch/arm64/kernel/efi-entry.S | 2 ++ arch/arm64/kernel/entry.S | 7 +++++++ arch/arm64/kernel/head.S | 14 ++++++++++++++ arch/arm64/kernel/hibernate-asm.S | 2 ++ arch/arm64/kernel/relocate_kernel.S | 2 ++ arch/arm64/kernel/sleep.S | 3 +++ arch/arm64/kvm/hyp/hyp-entry.S | 1 + arch/arm64/mm/trans_pgd-asm.S | 3 +++ 10 files changed, 38 insertions(+)
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 8c5a61aeaf8e..68db05428e4b 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h@@ -25,6 +25,7 @@ #include <asm/pgtable-hwdef.h> #include <asm/ptrace.h> #include <asm/thread_info.h> +#include <asm/unwind_hints.h> /* * Provide a wxN alias for each wN register so what we can paste a xN
@@ -147,6 +148,7 @@ lr .req x30 // link register */ .macro ventry label .align 7 + UNWIND_HINT_EMPTY b \label .endm
diff --git a/arch/arm64/kernel/cpu-reset.S b/arch/arm64/kernel/cpu-reset.S
index 48a8af97faa9..c9022042bdec 100644
--- a/arch/arm64/kernel/cpu-reset.S
+++ b/arch/arm64/kernel/cpu-reset.S@@ -10,6 +10,7 @@ #include <linux/linkage.h> #include <asm/assembler.h> #include <asm/sysreg.h> +#include <asm/unwind_hints.h> #include <asm/virt.h> .text
@@ -29,6 +30,7 @@ * flat identity mapping. */ SYM_CODE_START(cpu_soft_restart) + UNWIND_HINT_EMPTY mov_q x12, INIT_SCTLR_EL1_MMU_OFF pre_disable_mmu_workaround /*
diff --git a/arch/arm64/kernel/efi-entry.S b/arch/arm64/kernel/efi-entry.S
index 61a87fa1c305..9a1a94c3c4db 100644
--- a/arch/arm64/kernel/efi-entry.S
+++ b/arch/arm64/kernel/efi-entry.S@@ -9,10 +9,12 @@ #include <linux/init.h> #include <asm/assembler.h> +#include <asm/unwind_hints.h> __INIT SYM_CODE_START(efi_enter_kernel) + UNWIND_HINT_EMPTY /* * efi_pe_entry() will have copied the kernel image if necessary and we * end up here with device tree address in x1 and the kernel entry
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index c460ba2d009d..3bd11101e79d 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S@@ -28,6 +28,7 @@ #include <asm/thread_info.h> #include <asm/asm-uaccess.h> #include <asm/unistd.h> +#include <asm/unwind_hints.h> .macro clear_gp_regs .irp n,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29
@@ -37,6 +38,7 @@ .macro kernel_ventry, el:req, ht:req, regsize:req, label:req .align 7 + UNWIND_HINT_EMPTY .Lventry_start\@: .if \el == 0 /*
@@ -44,6 +46,7 @@ * skipped by the trampoline vectors, to trigger the cleanup. */ b .Lskip_tramp_vectors_cleanup\@ + UNWIND_HINT_EMPTY .if \regsize == 64 mrs x30, tpidrro_el0 msr tpidrro_el0, xzr
@@ -417,6 +420,7 @@ alternative_else_nop_endif ldp x24, x25, [sp, #16 * 12] ldp x26, x27, [sp, #16 * 13] ldp x28, x29, [sp, #16 * 14] + UNWIND_HINT_EMPTY .if \el == 0 alternative_if_not ARM64_UNMAP_KERNEL_AT_EL0
@@ -662,6 +666,7 @@ alternative_else_nop_endif .macro tramp_ventry, vector_start, regsize, kpti, bhb .align 7 + UNWIND_HINT_EMPTY 1: .if \regsize == 64 msr tpidrro_el0, x30 // Restored in kernel_ventry
@@ -687,6 +692,7 @@ alternative_else_nop_endif * enter the full-fat kernel vectors. */ bl 2f + UNWIND_HINT_EMPTY b . 2: tramp_map_kernel x30
@@ -717,6 +723,7 @@ alternative_else_nop_endif .endm .macro tramp_exit, regsize = 64 + UNWIND_HINT_EMPTY tramp_data_read_var x30, this_cpu_vector get_this_cpu_offset x29 ldr x30, [x30, x29]
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 6db9c3603bd8..2a66d18091eb 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S@@ -33,6 +33,7 @@ #include <asm/smp.h> #include <asm/sysreg.h> #include <asm/thread_info.h> +#include <asm/unwind_hints.h> #include <asm/virt.h> #include "efi-header.S"
@@ -63,6 +64,7 @@ * DO NOT MODIFY. Image header expected by Linux boot-loaders. */ efi_signature_nop // special NOP to identity as PE/COFF executable + UNWIND_HINT_EMPTY b primary_entry // branch to kernel start, magic .quad 0 // Image load offset from start of RAM, little-endian le64sym _kernel_size_le // Effective size of kernel image, little-endian
@@ -109,6 +111,7 @@ SYM_CODE_END(primary_entry) * Preserve the arguments passed by the bootloader in x0 .. x3 */ SYM_CODE_START_LOCAL(preserve_boot_args) + UNWIND_HINT_EMPTY mov x21, x0 // x21=FDT adr_l x0, boot_args // record the contents of
@@ -260,6 +263,7 @@ SYM_CODE_END(preserve_boot_args) * been enabled */ SYM_CODE_START_LOCAL(__create_page_tables) + UNWIND_HINT_EMPTY mov x28, lr /*
@@ -494,6 +498,7 @@ EXPORT_SYMBOL(kimage_vaddr) * booted in EL1 or EL2 respectively. */ SYM_CODE_START(init_kernel_el) + UNWIND_HINT_EMPTY mrs x0, CurrentEL cmp x0, #CurrentEL_EL2 b.eq init_el2
@@ -553,6 +558,7 @@ SYM_INNER_LABEL(init_el2, SYM_L_LOCAL) eret __cpu_stick_to_vhe: + UNWIND_HINT_EMPTY mov x0, #HVC_VHE_RESTART hvc #0 mov x0, #BOOT_CPU_MODE_EL2
@@ -564,6 +570,7 @@ SYM_CODE_END(init_kernel_el) * in w0. See arch/arm64/include/asm/virt.h for more info. */ SYM_CODE_START_LOCAL(set_cpu_boot_mode_flag) + UNWIND_HINT_EMPTY adr_l x1, __boot_cpu_mode cmp w0, #BOOT_CPU_MODE_EL2 b.ne 1f
@@ -607,6 +614,7 @@ SYM_DATA_END(__early_cpu_boot_status) * cores are held until we're ready for them to initialise. */ SYM_CODE_START(secondary_holding_pen) + UNWIND_HINT_EMPTY bl init_kernel_el // w0=cpu_boot_mode bl set_cpu_boot_mode_flag mrs x0, mpidr_el1
@@ -625,6 +633,7 @@ SYM_CODE_END(secondary_holding_pen) * be used where CPUs are brought online dynamically by the kernel. */ SYM_CODE_START(secondary_entry) + UNWIND_HINT_EMPTY bl init_kernel_el // w0=cpu_boot_mode bl set_cpu_boot_mode_flag b secondary_startup
@@ -644,6 +653,7 @@ SYM_CODE_START_LOCAL(secondary_startup) SYM_CODE_END(secondary_startup) SYM_CODE_START_LOCAL(__secondary_switched) + UNWIND_HINT_EMPTY adr_l x5, vectors msr vbar_el1, x5 isb
@@ -663,6 +673,7 @@ SYM_CODE_START_LOCAL(__secondary_switched) SYM_CODE_END(__secondary_switched) SYM_CODE_START_LOCAL(__secondary_too_slow) + UNWIND_HINT_EMPTY wfe wfi b __secondary_too_slow
@@ -699,6 +710,7 @@ SYM_CODE_END(__secondary_too_slow) * If it isn't, park the CPU */ SYM_CODE_START(__enable_mmu) + UNWIND_HINT_EMPTY mrs x2, ID_AA64MMFR0_EL1 ubfx x2, x2, #ID_AA64MMFR0_TGRAN_SHIFT, 4 cmp x2, #ID_AA64MMFR0_TGRAN_SUPPORTED_MIN
@@ -720,6 +732,7 @@ SYM_CODE_START(__enable_mmu) SYM_CODE_END(__enable_mmu) SYM_CODE_START_LOCAL(__cpu_secondary_check52bitva) + UNWIND_HINT_EMPTY #ifdef CONFIG_ARM64_VA_BITS_52 ldr_l x0, vabits_actual cmp x0, #52
@@ -751,6 +764,7 @@ SYM_CODE_END(__no_granule_support) #ifdef CONFIG_RELOCATABLE SYM_CODE_START_LOCAL(__relocate_kernel) + UNWIND_HINT_EMPTY /* * Iterate over each entry in the relocation table, and apply the * relocations in place.
diff --git a/arch/arm64/kernel/hibernate-asm.S b/arch/arm64/kernel/hibernate-asm.S
index 0e1d9c3c6a93..c0bec20bf0e0 100644
--- a/arch/arm64/kernel/hibernate-asm.S
+++ b/arch/arm64/kernel/hibernate-asm.S@@ -13,6 +13,7 @@ #include <asm/cputype.h> #include <asm/memory.h> #include <asm/page.h> +#include <asm/unwind_hints.h> #include <asm/virt.h> /*
@@ -46,6 +47,7 @@ */ .pushsection ".hibernate_exit.text", "ax" SYM_CODE_START(swsusp_arch_suspend_exit) + UNWIND_HINT_EMPTY /* * We execute from ttbr0, change ttbr1 to our copied linear map tables * with a break-before-make via the zero page
diff --git a/arch/arm64/kernel/relocate_kernel.S b/arch/arm64/kernel/relocate_kernel.S
index f0a3df9e18a3..f8cd8fcf2d4f 100644
--- a/arch/arm64/kernel/relocate_kernel.S
+++ b/arch/arm64/kernel/relocate_kernel.S@@ -16,6 +16,7 @@ #include <asm/page.h> #include <asm/sysreg.h> #include <asm/virt.h> +#include <asm/unwind_hints.h> .macro turn_off_mmu tmp1, tmp2 mov_q \tmp1, INIT_SCTLR_EL1_MMU_OFF
@@ -37,6 +38,7 @@ * safe memory that has been set up to be preserved during the copy operation. */ SYM_CODE_START(arm64_relocate_new_kernel) + UNWIND_HINT_EMPTY /* Setup the list loop variables. */ ldr x18, [x0, #KIMAGE_ARCH_ZERO_PAGE] /* x18 = zero page for BBM */ ldr x17, [x0, #KIMAGE_ARCH_TTBR1] /* x17 = linear map copy */
diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
index f0087e8bcd28..799ec01b0649 100644
--- a/arch/arm64/kernel/sleep.S
+++ b/arch/arm64/kernel/sleep.S@@ -4,6 +4,7 @@ #include <asm/asm-offsets.h> #include <asm/assembler.h> #include <asm/smp.h> +#include <asm/unwind_hints.h> .text /*
@@ -99,6 +100,7 @@ SYM_FUNC_END(__cpu_suspend_enter) .pushsection ".idmap.text", "awx" SYM_CODE_START(cpu_resume) + UNWIND_HINT_EMPTY bl init_kernel_el bl switch_to_vhe bl __cpu_setup
@@ -112,6 +114,7 @@ SYM_CODE_END(cpu_resume) .popsection SYM_CODE_START(_cpu_resume) + UNWIND_HINT_EMPTY mrs x1, mpidr_el1 adr_l x8, mpidr_hash // x8 = struct mpidr_hash virt address
diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S
index 7839d075729b..4a65262a4f3a 100644
--- a/arch/arm64/kvm/hyp/hyp-entry.S
+++ b/arch/arm64/kvm/hyp/hyp-entry.S@@ -14,6 +14,7 @@ #include <asm/kvm_asm.h> #include <asm/mmu.h> #include <asm/spectre.h> +#include <asm/unwind_hints.h> .macro save_caller_saved_regs_vect /* x0 and x1 were saved in the vector entry */
diff --git a/arch/arm64/mm/trans_pgd-asm.S b/arch/arm64/mm/trans_pgd-asm.S
index 021c31573bcb..148435248860 100644
--- a/arch/arm64/mm/trans_pgd-asm.S
+++ b/arch/arm64/mm/trans_pgd-asm.S@@ -8,10 +8,12 @@ #include <linux/linkage.h> #include <asm/assembler.h> #include <asm/kvm_asm.h> +#include <asm/unwind_hints.h> .macro invalid_vector label SYM_CODE_START_LOCAL(\label) .align 7 + UNWIND_HINT_EMPTY b \label SYM_CODE_END(\label) .endm
@@ -19,6 +21,7 @@ SYM_CODE_END(\label) .macro el1_sync_vector SYM_CODE_START_LOCAL(el1_sync) .align 7 + UNWIND_HINT_EMPTY cmp x0, #HVC_SET_VECTORS /* Called from hibernate */ b.ne 1f msr vbar_el2, x1
--
2.17.1