Re: [PATCH v2] scripts/link-vmlinux.sh: Add alias to duplicate symbols for kallsyms

Alessandro Carminati
2023-07-21T09:23:02Z

Hello Steven, Alexander, and Nick,

Since now I realize that a lot of people are working on my very same argument,
I'm writing you this mail just with the intent of not leaving my statements
floating in the air, and help the cause by sharing my experience, as little it
is, to solve this problem.

The addr2line strategy, I tried to implement, allows me to achieve the level
of accuracy that Luis mentioned in his comment about live-patching suggestions.
The addr2line-based approach is feasible, however, to make this approach
operable, I had to ensure that vmlinux contains the necessary debug
information.
Let me clarify.
During the kernel build, I do need the vmlinux to contain debug information.
The approach I pursued parses the nm output and, when it detects a duplicate
symbol, it needs to query vmlinux using addr2line to resolve the address
where the symbol is reported to be.
The whole process takes place during the building phase.
I've completed the work to integrate the new alias within the compilation
phase, and I wanted to share with you how it looks now.

```
~ # uname -a
Linux (none) 6.4.0 #1 SMP PREEMPT Thu Jul 20 10:05:36 UTC 2023 aarch64 GNU/Linux
~ # cat /proc/kallsyms | grep gic_mask_irq
ffffacf2eb64dae4 t gic_mask_irq
ffffacf2eb64dae4 t gic_mask_irq@_drivers_irqchip_irq-gic_c_167
ffffacf2eb650960 t gic_mask_irq
ffffacf2eb650960 t gic_mask_irq@_drivers_irqchip_irq-gic-v3_c_404
~ #
```

Despite this appearing to have a sufficient level of accuracy, when I tested
it, I realized something I really did not expect. Multiple instances of the
same function exist, and when I say "same function," I don't just mean the
name, but also the function's body. I apologize for stating something that
may sound obvious to you, but I found this really unexpected.

```
~ # uname -a
Linux (none) 6.4.0 #1 SMP PREEMPT Thu Jul 20 10:05:36 UTC 2023 aarch64 GNU/Linux
~ # cat /proc/kallsyms | grep -E " [ttT] " | cut -d" " -f3|sort| uniq -d| grep @_
BIT_initDStream@_lib_zstd_common_bitstream_h_259
__dev_hold@_include_linux_netdevice_h_4059
__dev_put@_include_linux_netdevice_h_4048
__flush_tlb_range@_arch_arm64_include_asm_tlbflush_h_291
__flush_tlb_range_constprop_0@_arch_arm64_include_asm_tlbflush_h_291
__kern_my_cpu_offset@_arch_arm64_include_asm_percpu_h_40
__kvm_nvhe_$x@_arch_arm64_kvm_hyp_include_nvhe_memory_h_22
__kvm_nvhe___kvm_skip_instr@_arch_arm64_kvm_hyp_include_hyp_adjust_pc_h_34
__kvm_nvhe_hyp_page_count@_arch_arm64_kvm_hyp_include_nvhe_memory_h_47
__kvm_nvhe_hyp_phys_to_virt@_arch_arm64_kvm_hyp_include_nvhe_memory_h_22
__kvm_nvhe_hyp_virt_to_phys@_arch_arm64_kvm_hyp_include_nvhe_memory_h_27
__kvm_skip_instr@_arch_arm64_kvm_hyp_include_hyp_adjust_pc_h_34
__nodes_weight_constprop_0@_include_linux_nodemask_h_239
__pi_$x@_scripts_dtc_libfdt_libfdt_h_145
__pi_fdt32_ld@_scripts_dtc_libfdt_libfdt_h_145
__preempt_count_dec_and_test@_arch_arm64_include_asm_current_h_19
acpi_dev_filter_resource_type_cb@_include_linux_acpi_h_520
add_quirk@_drivers_mmc_core_card_h_158
bpf_enable_instrumentation@_include_linux_bpf_h_1937
btf_id_cmp_func@_include_linux_btf_h_469
copy_from_sockptr_offset_constprop_0@_include_linux_sockptr_h_44
cpucap_multi_entry_cap_matches@_arch_arm64_include_asm_cpufeature_h_395
cpufreq_register_em_with_opp@_include_linux_cpufreq_h_1228
cpumask_weight@_include_linux_cpumask_h_691
cpumask_weight_constprop_0@_include_linux_cpumask_h_690
css_put@_include_linux_cgroup_refcnt_h_77
dma_cookie_status@_drivers_dma_dmaengine_h_74
dst_discard@_include_net_dst_h_392
dst_output@_include_net_dst_h_457
elf_core_dump@_fs_binfmt_elf_c_2027
fixup_use_fwh_lock@_drivers_mtd_chips_fwh_lock_h_102
flush_tlb_mm@_arch_arm64_include_asm_tlbflush_h_250
fwh_lock_varsize@_drivers_mtd_chips_fwh_lock_h_81
fwh_unlock_varsize@_drivers_mtd_chips_fwh_lock_h_92
fwh_xxlock_oneblock@_drivers_mtd_chips_fwh_lock_h_31
get_net_ns@_include_net_net_namespace_h_231
inline_map_read_isra_0@_include_linux_mtd_map_h_393
inline_map_write_part_0@_include_linux_mtd_map_h_426
io_run_task_work@_io_uring_io_uring_h_282
ipv6_portaddr_hash_isra_0@_include_net_ipv6_h_732
irq_find_host@_include_linux_irqdomain_h_322
jhash@_include_linux_jhash_h_76
jhash_constprop_0@_include_linux_jhash_h_76
ktime_get_boottime@_include_linux_timekeeping_h_94
ktime_get_real@_include_linux_timekeeping_h_78
load_elf_binary@_fs_binfmt_elf_c_824
load_elf_phdrs@_fs_binfmt_elf_c_468
may_use_simd@_arch_arm64_include_asm_alternative-macros_h_232
netif_tx_disable@_include_linux_netdevice_h_4486
of_parse_phandle@_include_linux_of_h_946
of_parse_phandle_constprop_0@_include_linux_of_h_943
padzero@_fs_binfmt_elf_c_142
percpu_down_read_constprop_0@_include_linux_percpu-rwsem_h_47
percpu_ref_get_many@_include_linux_percpu-refcount_h_199
percpu_ref_get_many_constprop_0@_include_linux_percpu-refcount_h_198
percpu_ref_put_many_constprop_0@_include_linux_percpu-refcount_h_326
percpu_up_read@_include_linux_percpu-rwsem_h_98
percpu_up_read_constprop_0@_include_linux_percpu-rwsem_h_97
pinconf_generic_dt_node_to_map_all@_include_linux_pinctrl_pinconf-generic_h_223
pinconf_generic_dt_node_to_map_group@_include_linux_pinctrl_pinconf-generic_h_207
pinconf_generic_dt_node_to_map_pin@_include_linux_pinctrl_pinconf-generic_h_215
platform_device_register_resndata_constprop_0@_include_linux_platform_device_h_125
ptrauth_keys_install_user@_arch_arm64_include_asm_alternative-macros_h_232
readl@_arch_arm64_include_asm_io_h_75
reqsk_put@_include_net_request_sock_h_133
rht_key_get_hash_constprop_0_isra_0@_include_linux_rhashtable_h_133
rht_key_get_hash_isra_0@_include_linux_rhashtable_h_125
role_show@_include_linux_device_h_763
sdhci_and_cqhci_reset@_drivers_mmc_host_sdhci-cqhci_h_16
set_active_memcg_part_0@_include_linux_sched_mm_h_410
set_brk@_fs_binfmt_elf_c_114
set_is_seen@_arch_arm64_include_asm_current_h_19
set_lookup@_arch_arm64_include_asm_current_h_19
sha1_base_init@_include_crypto_sha1_base_h_22
sha224_base_init@_include_crypto_sha256_base_h_23
sha256_base_init@_include_crypto_sha256_base_h_31
spi_sync_transfer_constprop_0@_include_linux_spi_spi_h_1339
spi_write@_include_linux_spi_spi_h_1363
tlb_flush@_arch_arm64_include_asm_tlb_h_54
trace_xhci_dbg_quirks@_drivers_usb_host_xhci-trace_h_48
udp_lib_close@_include_net_udp_h_197
udp_lib_hash@_include_net_udp_h_189
virtio_net_hdr_to_skb_constprop_0@_include_linux_virtio_net_h_48
writenote@_fs_binfmt_elf_c_1479
zero_user_segments@_include_linux_highmem_h_271
zero_user_segments_constprop_0@_include_linux_highmem_h_268
```

The previous evidence demonstrates that adding a tag with a file and line
number does not make a symbol unique.

Here, I inspect the function body to verify if the functions are indeed
the same.

```
Welcome to Buildroot
buildroot login: root
~ # cat /proc/kallsyms | grep set_brk
ffffa8a9d1cf1d2c t set_brk
ffffa8a9d1cf1d2c t set_brk@_fs_binfmt_elf_c_114
ffffa8a9d1cf4454 t set_brk
ffffa8a9d1cf4454 t set_brk@_fs_binfmt_elf_c_114
~ # QEMU: Terminated
$ cat System.map | grep set_brk
ffff8000082f1d2c t set_brk
ffff8000082f4454 t set_brk
~ $ r2 vmlinux
Warning: run r2 with -e bin.cache=true to fix relocations in disassembly
-- Reduce the delta where flag resolving by address is used with cfg.delta
[0xffff800008000000]> s 0xffff8000082f1d2c
[0xffff8000082f1d2c]> aa
[x] Analyze all flags starting with sym. and entry0 (aa)
[x] Analyze all functions arguments/locals
[0xffff8000082f1d2c]> pdf
; CALL XREFS from sym.load_elf_binary @ 0xffff8000082f352c(x), 0xffff8000082f38d4(x), 0xffff8000082f3a68(x)
â”Œ 112: sym.set_brk (int64_t arg1, int64_t arg2, int64_t arg3);
â”‚ ; arg int64_t arg1 @ x0
â”‚ ; arg int64_t arg2 @ x1
â”‚ ; arg int64_t arg3 @ x2
â”‚ ; var int64_t var_10h @ sp+0x10
â”‚ 0xffff8000082f1d2c 3f2303d5 paciasp ; binfmt_elf.c:114
â”‚ 0xffff8000082f1d30 fd7bbea9 stp x29, x30, [sp, -0x20]!
â”‚ 0xffff8000082f1d34 00fc3f91 add x0, x0, 0xfff ; binfmt_elf.c:115 ; arg1
â”‚ 0xffff8000082f1d38 fd030091 mov x29, sp ; binfmt_elf.c:114
â”‚ 0xffff8000082f1d3c 21fc3f91 add x1, x1, 0xfff ; binfmt_elf.c:116 ; arg2
â”‚ 0xffff8000082f1d40 00cc7492 and x0, x0, 0xfffffffffffff000 ; binfmt_elf.c:114 ; arg1
â”‚ 0xffff8000082f1d44 f30b00f9 str x19, [sp, 0x10] ; binfmt_elf.c:116
â”‚ 0xffff8000082f1d48 33cc7492 and x19, x1, 0xfffffffffffff000 ; arg2
â”‚ 0xffff8000082f1d4c 1f0013eb cmp x0, x19 ; binfmt_elf.c:117 ; arg1
â”‚ â”Œâ”€< 0xffff8000082f1d50 63010054 b.lo 0xffff8000082f1d7c
â”‚ â”Œâ”€â”€> 0xffff8000082f1d54 014138d5 mrs x1, sp_el0 ; binfmt_elf.c:128
â”‚ â•Žâ”‚ 0xffff8000082f1d58 22fc41f9 ldr x2, [x1, 0x3f8] ; current.h:21 ; 0xd9 ; 217
â”‚ â•Žâ”‚ 0xffff8000082f1d5c 00008052 mov w0, 0 ; binfmt_elf.c:129
â”‚ â•Žâ”‚ 0xffff8000082f1d60 539400f9 str x19, [x2, 0x128] ; binfmt_elf.c:128
â”‚ â•Žâ”‚ 0xffff8000082f1d64 21fc41f9 ldr x1, [x1, 0x3f8] ; current.h:17 ; 0xd9 ; 217
â”‚ â•Žâ”‚ 0xffff8000082f1d68 339000f9 str x19, [x1, 0x120] ; binfmt_elf.c:128
â”‚ â•Žâ”‚ 0xffff8000082f1d6c f30b40f9 ldr x19, [var_10h] ; binfmt_elf.c:129 ; 5
â”‚ â•Žâ”‚ 0xffff8000082f1d70 fd7bc2a8 ldp x29, x30, [sp], 0x20
â”‚ â•Žâ”‚ 0xffff8000082f1d74 bf2303d5 autiasp
â”‚ â•Žâ”‚ 0xffff8000082f1d78 c0035fd6 ret
â”‚ â•Žâ””â”€> 0xffff8000082f1d7c 42007e92 and x2, x2, 4 ; binfmt_elf.c:123 ; arg3
â”‚ â•Ž 0xffff8000082f1d80 610200cb sub x1, x19, x0 ; arg1
â”‚ â•Ž 0xffff8000082f1d84 cae3fc97 bl sym.vm_brk_flags
â”‚ â””â”€â”€< 0xffff8000082f1d88 60feff34 cbz w0, 0xffff8000082f1d54 ; binfmt_elf.c:125
â”‚ 0xffff8000082f1d8c f30b40f9 ldr x19, [var_10h] ; binfmt_elf.c:130 ; 5
â”‚ 0xffff8000082f1d90 fd7bc2a8 ldp x29, x30, [sp], 0x20
â”‚ 0xffff8000082f1d94 bf2303d5 autiasp
â”” 0xffff8000082f1d98 c0035fd6 ret
[0xffff8000082f1d2c]> s 0xffff8000082f4454
[0xffff8000082f4454]> pdf
; CALL XREFS from sym.load_elf_binary_1 @ 0xffff8000082f5cc0(x), 0xffff8000082f5e5c(x), 0xffff8000082f6648(x)
â”Œ 112: sym.set_brk_1 (int64_t arg1, int64_t arg2, int64_t arg3);
â”‚ ; arg int64_t arg1 @ x0
â”‚ ; arg int64_t arg2 @ x1
â”‚ ; arg int64_t arg3 @ x2
â”‚ ; var int64_t var_10h @ sp+0x10
â”‚ 0xffff8000082f4454 3f2303d5 paciasp ; binfmt_elf.c:114
â”‚ 0xffff8000082f4458 fd7bbea9 stp x29, x30, [sp, -0x20]!
â”‚ 0xffff8000082f445c 00fc3f91 add x0, x0, 0xfff ; binfmt_elf.c:115 ; arg1
â”‚ 0xffff8000082f4460 fd030091 mov x29, sp ; binfmt_elf.c:114
â”‚ 0xffff8000082f4464 21fc3f91 add x1, x1, 0xfff ; binfmt_elf.c:116 ; arg2
â”‚ 0xffff8000082f4468 00cc7492 and x0, x0, 0xfffffffffffff000 ; binfmt_elf.c:114 ; arg1
â”‚ 0xffff8000082f446c f30b00f9 str x19, [sp, 0x10] ; binfmt_elf.c:116
â”‚ 0xffff8000082f4470 33cc7492 and x19, x1, 0xfffffffffffff000 ; arg2
â”‚ 0xffff8000082f4474 1f0013eb cmp x0, x19 ; binfmt_elf.c:117 ; arg1
â”‚ â”Œâ”€< 0xffff8000082f4478 63010054 b.lo 0xffff8000082f44a4
â”‚ â”Œâ”€â”€> 0xffff8000082f447c 014138d5 mrs x1, sp_el0 ; binfmt_elf.c:128
â”‚ â•Žâ”‚ 0xffff8000082f4480 22fc41f9 ldr x2, [x1, 0x3f8] ; current.h:21 ; 0xd9 ; 217
â”‚ â•Žâ”‚ 0xffff8000082f4484 00008052 mov w0, 0 ; binfmt_elf.c:129
â”‚ â•Žâ”‚ 0xffff8000082f4488 539400f9 str x19, [x2, 0x128] ; binfmt_elf.c:128
â”‚ â•Žâ”‚ 0xffff8000082f448c 21fc41f9 ldr x1, [x1, 0x3f8] ; current.h:17 ; 0xd9 ; 217
â”‚ â•Žâ”‚ 0xffff8000082f4490 339000f9 str x19, [x1, 0x120] ; binfmt_elf.c:128
â”‚ â•Žâ”‚ 0xffff8000082f4494 f30b40f9 ldr x19, [var_10h] ; binfmt_elf.c:129 ; 5
â”‚ â•Žâ”‚ 0xffff8000082f4498 fd7bc2a8 ldp x29, x30, [sp], 0x20
â”‚ â•Žâ”‚ 0xffff8000082f449c bf2303d5 autiasp
â”‚ â•Žâ”‚ 0xffff8000082f44a0 c0035fd6 ret
â”‚ â•Žâ””â”€> 0xffff8000082f44a4 42007e92 and x2, x2, 4 ; binfmt_elf.c:123 ; arg3
â”‚ â•Ž 0xffff8000082f44a8 610200cb sub x1, x19, x0 ; arg1
â”‚ â•Ž 0xffff8000082f44ac 00dafc97 bl sym.vm_brk_flags
â”‚ â””â”€â”€< 0xffff8000082f44b0 60feff34 cbz w0, 0xffff8000082f447c ; binfmt_elf.c:125
â”‚ 0xffff8000082f44b4 f30b40f9 ldr x19, [var_10h] ; binfmt_elf.c:130 ; 5
â”‚ 0xffff8000082f44b8 fd7bc2a8 ldp x29, x30, [sp], 0x20
â”‚ 0xffff8000082f44bc bf2303d5 autiasp
â”” 0xffff8000082f44c0 c0035fd6 ret
[0xffff8000082f4454]>
```

While I can speculate on a reasonable explanation for why I see symbols coming
from header files being duplicated – when a header file is included in a C
file and it produces a function that the compiler does not want to inline, it
is replicated every time the file is included – I have no convincing
explanation as to why the fs/binfmt.c functions exist in more than one
instance.

```
elf_core_dump@_fs_binfmt_elf_c_2027
load_elf_binary@_fs_binfmt_elf_c_824
load_elf_phdrs@_fs_binfmt_elf_c_468
padzero@_fs_binfmt_elf_c_142
set_brk@_fs_binfmt_elf_c_114
writenote@_fs_binfmt_elf_c_1479
```

As a final note, please understand that my patch was not intended to undermine
anyone's work. I simply encountered a problem that I wanted to help solve.
Attached to this message is my code, in case anyone wants to replicate it.
I would appreciate being kept in the loop, as I genuinely want to assist in
fixing this problem.

BR
Alessandro
---
init/Kconfig | 36 ++++
scripts/Makefile | 4 +
scripts/kas_alias/Makefile | 4 +
scripts/kas_alias/a2l.c | 268 ++++++++++++++++++++++++++++
scripts/kas_alias/a2l.h | 32 ++++
scripts/kas_alias/duplicates_list.c | 70 ++++++++
scripts/kas_alias/duplicates_list.h | 15 ++
scripts/kas_alias/item_list.c | 230 ++++++++++++++++++++++++
scripts/kas_alias/item_list.h | 26 +++
scripts/kas_alias/kas_alias.c | 217 ++++++++++++++++++++++
scripts/link-vmlinux.sh | 11 +-
11 files changed, 910 insertions(+), 3 deletions(-)
create mode 100644 scripts/kas_alias/Makefile
create mode 100644 scripts/kas_alias/a2l.c
create mode 100644 scripts/kas_alias/a2l.h
create mode 100644 scripts/kas_alias/duplicates_list.c
create mode 100644 scripts/kas_alias/duplicates_list.h
create mode 100644 scripts/kas_alias/item_list.c
create mode 100644 scripts/kas_alias/item_list.h
create mode 100644 scripts/kas_alias/kas_alias.c

diff --git a/init/Kconfig b/init/Kconfig
index f7f65af4ee12..bc69fcd9cbc8 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1737,6 +1737,42 @@ config KALLSYMS_BASE_RELATIVE
time constants, and no relocation pass is required at runtime to fix
up the entries based on the runtime load address of the kernel.

+config KALLSYMS_ALIAS
+ bool "Produces alias for duplicated symbols" if EXPERT
+ depends on KALLSYMS && (DEBUG_INFO_DWARF4 || DEBUG_INFO_DWARF5)
+ help
+ It is not uncommon for drivers or modules related to similar
+ peripherals to have symbols with the exact same name.
+ While this is not a problem for the kernel's binary itself, it
+ becomes an issue when attempting to trace or probe specific
+ functions using infrastructure like ftrace or kprobe.
+
+ This option addresses this challenge by extending the symbol names
+ with unique suffixes during the kernel build process.
+ The newly created aliases for these duplicated symbols are unique
+ names that can be fed to the ftrace sysfs interface. By doing so, it
+ enables previously unreachable symbols to be probed.
+
+config CONFIG_KALLSYMS_ALIAS_DATA
+ bool "Produces alias also for data"
+ depends on KALLSYMS_ALIAS
+ help
+ Sometimes it can be useful to refer to data. In live patch scenarios,
+ you may find yourself needing to use symbols that are shared with
+ other functions. Since symbols face the same issue as functions, this
+ option allows you to create aliases for data as well.
+
+config CONFIG_KALLSYMS_ALIAS_DATA_ALL
+ bool "Removes all filter when producing data alias"
+ depends on CONFIG_KALLSYMS_ALIAS_DATA
+ help
+ When selecting data aliases, not all symbols are included in the set
+ This is because many symbols are unlikely to be used. If you choose
+ to have an alias for all data symbols, be aware that it will
+ significantly increase the size.
+
+ If unsure, say N.
+
# end of the "standard kernel features (expert users)" menu

# syscall, maps, verifier
diff --git a/scripts/Makefile b/scripts/Makefile
index 32b6ba722728..65fafe17cfe5 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -49,3 +49,7 @@ subdir-$(CONFIG_SECURITY_SELINUX) += selinux

# Let clean descend into subdirs
subdir- += basic dtc gdb kconfig mod
+
+# KALLSyms alias
+subdir-$(CONFIG_KALLSYMS_ALIAS) += kas_alias
+
diff --git a/scripts/kas_alias/Makefile b/scripts/kas_alias/Makefile
new file mode 100644
index 000000000000..e1fde69232b4
--- /dev/null
+++ b/scripts/kas_alias/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+hostprogs-always-$(CONFIG_KALLSYMS_ALIAS) += kas_alias
+
+kas_alias-objs := duplicates_list.o item_list.o kas_alias.o a2l.o
diff --git a/scripts/kas_alias/a2l.c b/scripts/kas_alias/a2l.c
new file mode 100644
index 000000000000..a9692ac30180
--- /dev/null
+++ b/scripts/kas_alias/a2l.c
@@ -0,0 +1,268 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <string.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "a2l.h"
+
+int addr2line_pid = -1;
+int a2l_in[2];
+int a2l_out[2];
+char line[MAX_BUF];
+char vmlinux_path[MAX_BUF];
+char addr2line_cmd[MAX_CMD_LEN];
+FILE *a2l_stdin, *a2l_stdout;
+
+static char *normalize_path(const char *input_path, char *output_path)
+{
+ char *prev_token = NULL;
+ char *delimiter = "/";
+ char inbuf[MAX_BUF];
+ char *token;
+ char *pos;
+
+ memset(inbuf, 0, MAX_BUF);
+ *output_path = '\0';
+ strncpy(inbuf, input_path, MAX_BUF);
+ if (!input_path || !output_path || strlen(input_path) == 0)
+ return NULL;
+
+ token = strtok(inbuf, delimiter);
+ while (token) {
+ if (strcmp(token, "..") == 0 && prev_token) {
+ pos = strrchr(output_path, '/');
+ if (pos)
+ *pos = '\0';
+
+ } else if (strcmp(token, ".") != 0) {
+ strcat(output_path, "/");
+ strcat(output_path, token);
+ }
+
+ prev_token = token;
+ token = strtok(NULL, delimiter);
+ }
+
+ return output_path;
+}
+
+static void path_of(const char *full_path, char *path)
+{
+ const char *last_slash = strrchr(full_path, '/');
+ size_t path_length;
+ char cwd[MAX_BUF];
+
+ if (!last_slash) {
+ if (getcwd(cwd, sizeof(cwd)))
+ strcpy(path, cwd);
+ else
+ strcpy(path, ".");
+ } else {
+ path_length = last_slash - full_path;
+ strncpy(path, full_path, path_length);
+ path[path_length] = '\0';
+ }
+}
+
+static bool file_exists(const char *file_path)
+{
+ FILE *file;
+
+ file = fopen(file_path, "r");
+ if (file) {
+ fclose(file);
+ return true;
+ }
+ return false;
+}
+
+int addr2line_init(const char *cmd, const char *vmlinux)
+{
+ if ((!file_exists(cmd)) || (!file_exists(vmlinux))) {
+ printf("file not found\n");
+ return 0;
+ }
+
+ path_of(vmlinux, vmlinux_path);
+ if (pipe(a2l_in) == -1) {
+ printf("Failed to create pipe\n");
+ return 0;
+ }
+
+ if (pipe(a2l_out) == -1) {
+ printf("Failed to create pipe\n");
+ return 0;
+ }
+
+ addr2line_pid = fork();
+ if (addr2line_pid == -1) {
+ printf("Failed to fork process\n");
+ close(a2l_in[P_READ]);
+ close(a2l_in[P_WRITE]);
+ close(a2l_out[P_READ]);
+ close(a2l_out[P_WRITE]);
+ return 0;
+ }
+
+ if (addr2line_pid == 0) {
+ dup2(a2l_in[P_READ], 0);
+ dup2(a2l_out[P_WRITE], 1);
+ close(a2l_in[P_WRITE]);
+ close(a2l_out[P_READ]);
+
+ execlp(cmd, cmd, ADDR2LINE_ARGS, vmlinux, NULL);
+
+ printf("Failed to execute addr2line command\n");
+ exit(1);
+ } else {
+ close(a2l_in[P_READ]);
+ close(a2l_out[P_WRITE]);
+ }
+
+ a2l_stdin = fdopen(a2l_in[P_WRITE], "w");
+ if (!a2l_stdin) {
+ printf("Failed to open pipe a2l_in\n");
+ return 0;
+ }
+
+ a2l_stdout = fdopen(a2l_out[P_READ], "r");
+ if (!a2l_stdout) {
+ printf("Failed to open pipe a2l_out\n");
+ fclose(a2l_stdin);
+ return 0;
+ }
+
+ return 1;
+}
+
+const char *remove_subdir(const char *home, const char *f_path)
+{
+ int i = 0;
+
+ while (*(home + i) == *(f_path + i))
+ i++;
+
+ return (strlen(home) != i) ? NULL : f_path + i;
+}
+
+char *addr2line_get_lines(uint64_t address)
+{
+ char buf[MAX_BUF];
+
+ fprintf(a2l_stdin, "%08lx\n", address);
+ fflush(a2l_stdin);
+
+ if (!fgets(line, sizeof(line), a2l_stdout)) {
+ printf("Failed to read lines from addr2line\n");
+ return NULL;
+ }
+
+ if (!fgets(line, sizeof(line), a2l_stdout)) {
+ printf("Failed to read lines from addr2line\n");
+ return NULL;
+ }
+
+ line[strcspn(line, "\n")] = '\0';
+ strncpy(buf, line, MAX_BUF);
+ return normalize_path(buf, line);
+}
+
+int addr2line_cleanup(void)
+{
+ int status;
+
+ if (addr2line_pid != -1) {
+ kill(addr2line_pid, SIGKILL);
+ waitpid(addr2line_pid, &status, 0);
+ fclose(a2l_stdin);
+ fclose(a2l_stdout);
+ addr2line_pid = -1;
+ }
+
+ return 1;
+}
+
+static char *find_executable(const char *command)
+{
+ char *path_env = getenv("PATH");
+ char *executable_path;
+ char *path_copy;
+ char *path;
+ int n;
+
+ if (!path_env)
+ return NULL;
+
+ path_copy = strdup(path_env);
+ if (!path_copy)
+ return NULL;
+
+ path = strtok(path_copy, ":");
+ while (path) {
+ n = snprintf(0, 0, "%s/%s", path, command);
+ executable_path = (char *)malloc(n + 1);
+ snprintf(executable_path, n + 1, "%s/%s", path, command);
+ if (access(executable_path, X_OK) == 0) {
+ free(path_copy);
+ return executable_path;
+ }
+
+ path = strtok(NULL, ":");
+ free(executable_path);
+ executable_path = NULL;
+ }
+
+ free(path_copy);
+ if (executable_path)
+ free(executable_path);
+ return NULL;
+}
+
+const char *get_addr2line(int mode)
+{
+ char *buf = "";
+
+ switch (mode) {
+ case A2L_CROSS:
+ buf = getenv("CROSS_COMPILE");
+ memcpy(addr2line_cmd, buf, strlen(buf));
+ case A2L_DEFAULT:
+ memcpy(addr2line_cmd + strlen(buf), ADDR2LINE, strlen(ADDR2LINE));
+ buf = find_executable(addr2line_cmd);
+ if (buf) {
+ memcpy(addr2line_cmd, buf, strlen(buf));
+ free(buf);
+ }
+ return addr2line_cmd;
+ case A2L_LLVM:
+ default:
+ return NULL;
+ }
+}
+
+char *get_vmlinux(char *input)
+{
+ const char *match_string1 = ".syms";
+ const char *match_string2 = ".tmp_vmlinux.kallsyms";
+ char *result = NULL;
+ char *match_pos;
+
+ match_pos = strstr(input, match_string1);
+ if (!match_pos)
+ return NULL;
+
+ match_pos = strstr(input, match_string2);
+ if (!match_pos)
+ return NULL;
+
+ result = strdup(input);
+ match_pos = strstr(result, match_string1);
+ *match_pos = '\0';
+ return result;
+}
diff --git a/scripts/kas_alias/a2l.h b/scripts/kas_alias/a2l.h
new file mode 100644
index 000000000000..ca6419229dde
--- /dev/null
+++ b/scripts/kas_alias/a2l.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef A2L_H
+#define A2L_H
+#include <stdint.h>
+
+#define ADDR2LINE "addr2line"
+#define ADDR2LINE_ARGS "-fe"
+//#define VMLINUX "vmlinux"
+#define MAX_BUF 4096
+#define MAX_CMD_LEN 256
+#define P_READ 0
+#define P_WRITE 1
+#define A2L_DEFAULT 1
+#define A2L_CROSS 2
+#define A2L_LLVM 3
+#define A2L_MAKE_VALUE 2
+
+extern int addr2line_pid;
+extern int a2l_in[2];
+extern int a2l_out[2];
+extern char line[MAX_BUF];
+extern char vmlinux_path[MAX_BUF];
+extern char addr2line_cmd[MAX_CMD_LEN];
+
+int addr2line_init(const char *cmd, const char *vmlinux);
+char *addr2line_get_lines(uint64_t address);
+int addr2line_cleanup(void);
+const char *remove_subdir(const char *home, const char *f_path);
+const char *get_addr2line(int mode);
+char *get_vmlinux(char *input);
+
+#endif
diff --git a/scripts/kas_alias/duplicates_list.c b/scripts/kas_alias/duplicates_list.c
new file mode 100644
index 000000000000..e7a3d2917937
--- /dev/null
+++ b/scripts/kas_alias/duplicates_list.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+#include "item_list.h"
+#include "duplicates_list.h"
+
+struct duplicate_item *find_duplicates(struct item *list)
+{
+ struct duplicate_item *current_duplicate = NULL;
+ struct duplicate_item *duplicates = NULL;
+ struct duplicate_item *new_duplicate;
+ struct item *current_item = list;
+ bool prev_was_duplicate = false;
+ struct item *prev_item = NULL;
+
+ while (current_item) {
+ if ((prev_item && (strcmp(current_item->symb_name, prev_item->symb_name) == 0)) ||
+ prev_was_duplicate) {
+ if (!duplicates) {
+ duplicates = malloc(sizeof(struct duplicate_item));
+ if (!duplicates)
+ return NULL;
+
+ duplicates->original_item = prev_item;
+ duplicates->next = NULL;
+ current_duplicate = duplicates;
+ } else {
+ new_duplicate = malloc(sizeof(struct duplicate_item));
+ if (!new_duplicate) {
+ free_duplicates(&duplicates);
+ return NULL;
+ }
+
+ new_duplicate->original_item = prev_item;
+ new_duplicate->next = NULL;
+ current_duplicate->next = new_duplicate;
+ current_duplicate = new_duplicate;
+
+ if ((strcmp(current_item->symb_name, prev_item->symb_name) != 0) &&
+ (prev_was_duplicate))
+ prev_was_duplicate = false;
+ else
+ prev_was_duplicate = true;
+ }
+ }
+
+ prev_item = current_item;
+ current_item = current_item->next;
+ }
+
+ return duplicates;
+}
+
+void free_duplicates(struct duplicate_item **duplicates)
+{
+ struct duplicate_item *duplicates_iterator = *duplicates;
+ struct duplicate_item *app;
+
+ while (duplicates_iterator) {
+ app = duplicates_iterator;
+ duplicates_iterator = duplicates_iterator->next;
+ free(app);
+ }
+
+ *duplicates = NULL;
+}
diff --git a/scripts/kas_alias/duplicates_list.h b/scripts/kas_alias/duplicates_list.h
new file mode 100644
index 000000000000..76aa73e584bc
--- /dev/null
+++ b/scripts/kas_alias/duplicates_list.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef DUPLICATES_LIST_H
+#define DUPLICATES_LIST_H
+
+#include "item_list.h"
+
+struct duplicate_item {
+ struct item *original_item;
+ struct duplicate_item *next;
+};
+
+struct duplicate_item *find_duplicates(struct item *list);
+void free_duplicates(struct duplicate_item **duplicates);
+
+#endif
diff --git a/scripts/kas_alias/item_list.c b/scripts/kas_alias/item_list.c
new file mode 100644
index 000000000000..48f2e525592a
--- /dev/null
+++ b/scripts/kas_alias/item_list.c
@@ -0,0 +1,230 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdbool.h>
+#include <assert.h>
+#include "item_list.h"
+
+#define CHECK_ORDER_BY_ADDRESS(sort_by, current, temp, op) \
+ ((sort_by) == BY_ADDRESS && (current)->addr op (temp)->addr)
+#define CHECK_ORDER_BY_NAME(sort_by, current, temp, op) \
+ ((sort_by) == BY_NAME && strcmp((current)->symb_name, (temp)->symb_name) op 0)
+
+struct item *list_index[96] = {0};
+
+void build_index(struct item *list)
+{
+ char current_first_letter = ' ';
+ struct item *current = list;
+
+ while (current) {
+ if (current->symb_name[0] != current_first_letter) {
+ current_first_letter = current->symb_name[0];
+ list_index[current_first_letter - 32] = current;
+ }
+ current = current->next;
+ }
+}
+
+struct item *add_item(struct item **list, const char *name, char stype, uint64_t addr)
+{
+ struct item *new_item;
+ struct item *current;
+
+ new_item = malloc(sizeof(struct item));
+ if (!new_item)
+ return NULL;
+
+ strncpy(new_item->symb_name, name, MAX_NAME_SIZE);
+ new_item->symb_name[MAX_NAME_SIZE - 1] = '\0';
+ new_item->addr = addr;
+ new_item->stype = stype;
+ new_item->next = NULL;
+
+ if (!(*list)) {
+ *list = new_item;
+ } else {
+ current = *list;
+ while (current->next)
+ current = current->next;
+
+ current->next = new_item;
+ }
+ return new_item;
+}
+
+void sort_list(struct item **list, int sort_by)
+{
+ struct item *current = *list;
+ struct item *sorted = NULL;
+ struct item *next_item;
+ struct item *temp;
+
+ if (!(*list) || !((*list)->next))
+ return;
+
+ while (current) {
+ next_item = current->next;
+ if (!sorted ||
+ (CHECK_ORDER_BY_ADDRESS(sort_by, current, sorted, <) ||
+ CHECK_ORDER_BY_NAME(sort_by, current, sorted, >=))) {
+ current->next = sorted;
+ sorted = current;
+ } else {
+ temp = sorted;
+ while (temp->next &&
+ (CHECK_ORDER_BY_ADDRESS(sort_by, current, temp->next, >=) ||
+ CHECK_ORDER_BY_NAME(sort_by, current, temp->next, >=)))
+ temp = temp->next;
+
+ current->next = temp->next;
+ temp->next = current;
+ }
+ current = next_item;
+ }
+
+ *list = sorted;
+}
+
+struct item *merge(struct item *left, struct item *right, int sort_by)
+{
+ struct item *current = NULL;
+ struct item *result = NULL;
+
+ if (!left)
+ return right;
+ if (!right)
+ return left;
+
+ if (sort_by == BY_NAME) {
+ if (strcmp(left->symb_name, right->symb_name) <= 0) {
+ result = left;
+ left = left->next;
+ } else {
+ result = right;
+ right = right->next;
+ }
+ } else {
+ if (sort_by == BY_ADDRESS) {
+ if (left->addr <= right->addr) {
+ result = left;
+ left = left->next;
+ } else {
+ result = right;
+ right = right->next;
+ }
+ }
+ }
+
+ current = result;
+
+ while (left && right) {
+ if (sort_by == BY_NAME) {
+ if (strcmp(left->symb_name, right->symb_name) <= 0) {
+ current->next = left;
+ left = left->next;
+ } else {
+ current->next = right;
+ right = right->next;
+ }
+ } else {
+ if (sort_by == BY_ADDRESS) {
+ if (left->addr <= right->addr) {
+ current->next = left;
+ left = left->next;
+ } else {
+ current->next = right;
+ right = right->next;
+ }
+ }
+ }
+
+ current = current->next;
+ }
+
+ if (left) {
+ current->next = left;
+ } else {
+ if (right)
+ current->next = right;
+ }
+
+ return result;
+}
+
+struct item *merge_sort(struct item *head, int sort_by)
+{
+ struct item *right;
+ struct item *slow;
+ struct item *fast;
+ struct item *left;
+
+ if (!head || !head->next)
+ return head;
+
+ slow = head;
+ fast = head->next;
+
+ while (fast && fast->next) {
+ slow = slow->next;
+ fast = fast->next->next;
+ }
+
+ left = head;
+ right = slow->next;
+ slow->next = NULL;
+
+ left = merge_sort(left, sort_by);
+ right = merge_sort(right, sort_by);
+
+ return merge(left, right, sort_by);
+}
+
+void sort_list_m(struct item **head, int sort_by)
+{
+ if (!(*head) || !((*head)->next))
+ return;
+
+ *head = merge_sort(*head, sort_by);
+}
+
+int insert_after(struct item *list, const uint64_t search_addr,
+ const char *name, uint64_t addr, char stype)
+{
+ struct item *new_item;
+ struct item *current;
+ int ret = 0;
+
+ current = (list_index[name[0] - 32]) ? list_index[name[0] - 32] : list;
+ while (current) {
+ if (current->addr == search_addr) {
+ new_item = malloc(sizeof(struct item));
+ if (!new_item)
+ return ret;
+ strncpy(new_item->symb_name, name, MAX_NAME_SIZE);
+ new_item->symb_name[MAX_NAME_SIZE - 1] = '\0';
+ new_item->addr = addr;
+ new_item->stype = stype;
+ new_item->next = current->next;
+ current->next = new_item;
+ ret = 1;
+ break;
+ }
+ current = current->next;
+ }
+ return ret;
+}
+
+void free_items(struct item **head)
+{
+ struct item *app, *item_iterator = *head;
+
+ while (item_iterator) {
+ app = item_iterator;
+ item_iterator = item_iterator->next;
+ free(app);
+ }
+ *head = NULL;
+}
diff --git a/scripts/kas_alias/item_list.h b/scripts/kas_alias/item_list.h
new file mode 100644
index 000000000000..b4891cb088ee
--- /dev/null
+++ b/scripts/kas_alias/item_list.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef ITEM_LIST_H
+#define ITEM_LIST_H
+#include <stdint.h>
+
+#define MAX_NAME_SIZE 256
+#define BY_ADDRESS 1
+#define BY_NAME 2
+
+struct item {
+ char symb_name[MAX_NAME_SIZE];
+ uint64_t addr;
+ char stype;
+ struct item *next;
+};
+
+void build_index(struct item *list);
+struct item *add_item(struct item **list, const char *name, char stype, uint64_t addr);
+void sort_list(struct item **list, int sort_by);
+struct item *merge(struct item *left, struct item *right, int sort_by);
+struct item *merge_sort(struct item *head, int sort_by);
+void sort_list_m(struct item **head, int sort_by);
+int insert_after(struct item *list, const uint64_t search_addr,
+ const char *name, uint64_t addr, char stype);
+void free_items(struct item **head);
+#endif
diff --git a/scripts/kas_alias/kas_alias.c b/scripts/kas_alias/kas_alias.c
new file mode 100644
index 000000000000..532aeb39f851
--- /dev/null
+++ b/scripts/kas_alias/kas_alias.c
@@ -0,0 +1,217 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdbool.h>
+#include <stdarg.h>
+#include <regex.h>
+
+#include "item_list.h"
+#include "duplicates_list.h"
+#include "a2l.h"
+
+#define SYMB_IS_TEXT(s) ((((s)->stype) == 't') || (((s)->stype) == 'T'))
+#define SYMB_IS_DATA(s) ((((s)->stype) == 'b') || (((s)->stype) == 'B') || \
+ (((s)->stype) == 'd') || (((s)->stype) == 'D') || \
+ (((s)->stype) == 'r') || (((s)->stype) == 'R'))
+#ifdef CONFIG_KALLSYMS_ALIAS_DATA
+#define SYMB_NEEDS_ALIAS(s) (SYMB_IS_TEXT(s) || SYMB_IS_DATA(s))
+#else
+#define SYMB_NEEDS_ALIAS(s) SYMB_IS_TEXT(s)
+#endif
+#define FNOMATCH 0
+#define FMATCH 1
+#define EREGEX 2
+
+const char *ignore_regex[] = {
+ "^__cfi_.*$", // __cfi_ preamble
+#ifndef CONFIG_KALLSYMS_ALIAS_DATA_ALL
+ "^_*TRACE_SYSTEM.*$",
+ "^__already_done\\.[0-9]+$", // Call a function once data
+ "^___tp_str\\.[0-9]+$",
+ "^___done\\.[0-9]+$",
+ "^__print_once\\.[0-9]+$",
+ "^_rs\\.[0-9]+$",
+ "^__compound_literal\\.[0-9]+$",
+ "^___once_key\\.[0-9]+$",
+ "^__func__\\.[0-9]+$",
+ "^__msg\\.[0-9]+$",
+ "^CSWTCH\\.[0-9]+$",
+ "^__flags\\.[0-9]+$",
+ "^__wkey.*$",
+ "^__mkey.*$",
+ "^__key.*$",
+#endif
+ "^__pfx_.*$" // NOP-padding
+};
+
+int suffix_serial;
+
+static inline void verbose_msg(bool verbose, const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ if (verbose)
+ printf(fmt, args);
+
+ va_end(args);
+}
+
+static void create_suffix(const char *name, char *output_suffix)
+{
+ sprintf(output_suffix, "%s__alias__%d", name, suffix_serial++);
+}
+
+static void create_file_suffix(const char *name, uint64_t address, char *output_suffix, char *cwd)
+{
+ const char *f_path;
+ char *buf;
+ int i = 0;
+
+ buf = addr2line_get_lines(address);
+ f_path = remove_subdir(cwd, buf);
+ if (f_path) {
+ sprintf(output_suffix, "%s@%s", name, f_path);
+ while (*(output_suffix + i) != '\0') {
+ switch (*(output_suffix + i)) {
+ case '/':
+ case ':':
+ case '.':
+ *(output_suffix + i) = '_';
+ break;
+ default:
+ }
+ i++;
+ }
+ } else {
+ create_suffix(name, output_suffix);
+ }
+}
+
+static int filter_symbols(char *symbol, const char **ignore_list, int regex_no)
+{
+ regex_t regex;
+ int res, i;
+
+ for (i = 0; i < regex_no; i++) {
+ res = regcomp(&regex, ignore_list[i], REG_EXTENDED);
+ if (res)
+ return -EREGEX;
+
+ res = regexec(&regex, symbol, 0, NULL, 0);
+ regfree(&regex);
+ switch (res) {
+ case 0:
+ return FMATCH;
+ case REG_NOMATCH:
+ break;
+ default:
+ return -EREGEX;
+ }
+ }
+
+ return FNOMATCH;
+}
+
+int main(int argc, char *argv[])
+{
+ char t, sym_name[MAX_NAME_SIZE], new_name[MAX_NAME_SIZE + 15];
+ struct duplicate_item *duplicate_iterator;
+ struct duplicate_item *duplicate;
+ struct item *head = {NULL};
+ bool need_2_process = true;
+ struct item *last = {NULL};
+ struct item *current;
+ int verbose_mode = 0;
+ uint64_t address;
+ FILE *fp;
+ int res;
+
+ if (argc < 2 || argc > 3) {
+ printf("Usage: %s <nmfile> [-verbose]\n", argv[0]);
+ return 1;
+ }
+
+ if (argc == 3 && strcmp(argv[2], "-verbose") == 0)
+ verbose_mode = 1;
+
+ verbose_msg(verbose_mode, "Scanning nm data(%s)\n", argv[1]);
+
+ fp = fopen(argv[1], "r");
+ if (!fp) {
+ printf("Can't open input file.\n");
+ return 1;
+ }
+
+ if (!addr2line_init(get_addr2line(A2L_DEFAULT), get_vmlinux(argv[1])))
+ return 1;
+
+ while (fscanf(fp, "%lx %c %99s\n", &address, &t, sym_name) == 3) {
+ if (strstr(sym_name, "@_")) {
+ if (verbose_mode && need_2_process)
+ printf("Already processed\n");
+ need_2_process = false;
+ }
+ last = add_item(&last, sym_name, t, address);
+ if (!last) {
+ printf("Error in allocate memory\n");
+ free_items(&head);
+ return 1;
+ }
+
+ if (!head)
+ head = last;
+ }
+
+ fclose(fp);
+
+ if (need_2_process) {
+ verbose_msg(verbose_mode, "Sorting nm data\n");
+ sort_list_m(&head, BY_NAME);
+ verbose_msg(verbose_mode, "Scanning nm data for duplicates\n");
+ duplicate = find_duplicates(head);
+ if (!duplicate) {
+ printf("Error in duplicates list\n");
+ return 1;
+ }
+
+ verbose_msg(verbose_mode, "Applying suffixes\n");
+ build_index(head);
+ duplicate_iterator = duplicate;
+ while (duplicate_iterator) {
+ res = filter_symbols(duplicate_iterator->original_item->symb_name,
+ ignore_regex, sizeof(ignore_regex) /
+ sizeof(ignore_regex[0]));
+ if (res != FMATCH &&
+ SYMB_NEEDS_ALIAS(duplicate_iterator->original_item)) {
+ if (res < 0)
+ return 1;
+
+ create_file_suffix(duplicate_iterator->original_item->symb_name,
+ duplicate_iterator->original_item->addr,
+ new_name, vmlinux_path);
+ if (!insert_after(head, duplicate_iterator->original_item->addr,
+ new_name, duplicate_iterator->original_item->addr,
+ duplicate_iterator->original_item->stype))
+ return 1;
+ }
+
+ duplicate_iterator = duplicate_iterator->next;
+ }
+
+ sort_list_m(&head, BY_ADDRESS);
+ }
+ current = head;
+ while (current) {
+ printf("%08lx %c %s\n", current->addr, current->stype, current->symb_name);
+ current = current->next;
+ }
+
+ free_items(&head);
+ free_duplicates(&duplicate);
+ addr2line_cleanup();
+ return 0;
+}
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index a432b171be82..cacf60b597ce 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -89,8 +89,9 @@ vmlinux_link()

ldflags="${ldflags} ${wl}--script=${objtree}/${KBUILD_LDS}"

- # The kallsyms linking does not need debug symbols included.
- if [ "$output" != "${output#.tmp_vmlinux.kallsyms}" ] ; then
+ # The kallsyms linking does not need debug symbols included, unless the KALLSYMS_ALIAS.
+ if [ ! is_enabled CONFIG_KALLSYMS_ALIAS ] && \
+ [ "$output" != "${output#.tmp_vmlinux.kallsyms}" ] ; then
ldflags="${ldflags} ${wl}--strip-debug"
fi

@@ -161,7 +162,11 @@ kallsyms()
fi

info KSYMS ${2}
- scripts/kallsyms ${kallsymopt} ${1} > ${2}
+ if is_enabled CONFIG_KALLSYMS_ALIAS; then
+ ALIAS=".alias"
+ scripts/kas_alias/kas_alias ${1} >${1}${ALIAS}
+ fi
+ scripts/kallsyms ${kallsymopt} ${1}${ALIAS} > ${2}
}

# Perform one step in kallsyms generation, including temporary linking of
--
2.34.1