2022-10-22 23:09:14

by Jim Cromie

[permalink] [raw]
Subject: [PATCH 0/2] vmlinux.lds.h tweaks

hi Greg,

These 2 patches are "no functional change", but they are a simple step
towards de-duplicating the repetitive columms in the __dyndbg section.

For a DYNAMIC_DEBUG=y kernel with 5k pr_debugs/drm.debugs, the
footprint reduction should be ~100 KiB

Jim Cromie (2):
vmlinux.lds.h: add BOUNDED_SECTION* macros
vmlinux.lds.h: place optional header space in BOUNDED_SECTION

include/asm-generic/vmlinux.lds.h | 221 +++++++++++-------------------
1 file changed, 81 insertions(+), 140 deletions(-)

CC: Suren Baghdasaryan <[email protected]>
CC: Kent Overstreet <[email protected]>
Signed-off-by: Jim Cromie <[email protected]>

--
2.37.3


2022-10-22 23:09:15

by Jim Cromie

[permalink] [raw]
Subject: [PATCH 1/2] vmlinux.lds.h: add BOUNDED_SECTION* macros

vmlinux.lds.h has ~45 occurrences of this general pattern:

__start_foo = .;
KEEP(*(foo))
__stop_foo = .;

Reduce this pattern to a (group of 4) macros, and use them to reduce
linecount. This was inspired by the codetag patchset.

no functional change.

CC: Suren Baghdasaryan <[email protected]>
CC: Kent Overstreet <[email protected]>
Signed-off-by: Jim Cromie <[email protected]>
---

Shall we bikeshed the names ?
---
include/asm-generic/vmlinux.lds.h | 219 +++++++++++-------------------
1 file changed, 79 insertions(+), 140 deletions(-)

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index c15de165ec8f..9f6352171f88 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -193,100 +193,99 @@
# endif
#endif

+#define BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _s_, _e_) \
+ _s_##_label_ = .; \
+ KEEP(*(_sec_)) \
+ _e_##_label_ = .;
+
+#define BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _s_, _e_) \
+ _label_##_s_ = .; \
+ KEEP(*(_sec_)) \
+ _label_##_e_ = .;
+
+#define BOUNDED_SECTION_BY(_sec_, _label_) \
+ BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, __start, __stop)
+
+#define BOUNDED_SECTION(_sec) BOUNDED_SECTION_BY(_sec, _sec)
+
#ifdef CONFIG_TRACE_BRANCH_PROFILING
-#define LIKELY_PROFILE() __start_annotated_branch_profile = .; \
- KEEP(*(_ftrace_annotated_branch)) \
- __stop_annotated_branch_profile = .;
+#define LIKELY_PROFILE() \
+ BOUNDED_SECTION_BY(_ftrace_annotated_branch, _annotated_branch_profile)
#else
#define LIKELY_PROFILE()
#endif

#ifdef CONFIG_PROFILE_ALL_BRANCHES
-#define BRANCH_PROFILE() __start_branch_profile = .; \
- KEEP(*(_ftrace_branch)) \
- __stop_branch_profile = .;
+#define BRANCH_PROFILE() \
+ BOUNDED_SECTION_BY(_ftrace_branch, _branch_profile)
#else
#define BRANCH_PROFILE()
#endif

#ifdef CONFIG_KPROBES
-#define KPROBE_BLACKLIST() . = ALIGN(8); \
- __start_kprobe_blacklist = .; \
- KEEP(*(_kprobe_blacklist)) \
- __stop_kprobe_blacklist = .;
+#define KPROBE_BLACKLIST() \
+ . = ALIGN(8); \
+ BOUNDED_SECTION(_kprobe_blacklist)
#else
#define KPROBE_BLACKLIST()
#endif

#ifdef CONFIG_FUNCTION_ERROR_INJECTION
-#define ERROR_INJECT_WHITELIST() STRUCT_ALIGN(); \
- __start_error_injection_whitelist = .; \
- KEEP(*(_error_injection_whitelist)) \
- __stop_error_injection_whitelist = .;
+#define ERROR_INJECT_WHITELIST() \
+ STRUCT_ALIGN(); \
+ BOUNDED_SECTION(_error_injection_whitelist)
#else
#define ERROR_INJECT_WHITELIST()
#endif

#ifdef CONFIG_EVENT_TRACING
-#define FTRACE_EVENTS() . = ALIGN(8); \
- __start_ftrace_events = .; \
- KEEP(*(_ftrace_events)) \
- __stop_ftrace_events = .; \
- __start_ftrace_eval_maps = .; \
- KEEP(*(_ftrace_eval_map)) \
- __stop_ftrace_eval_maps = .;
+#define FTRACE_EVENTS() \
+ . = ALIGN(8); \
+ BOUNDED_SECTION(_ftrace_events) \
+ BOUNDED_SECTION_BY(_ftrace_eval_map, _ftrace_eval_maps)
#else
#define FTRACE_EVENTS()
#endif

#ifdef CONFIG_TRACING
-#define TRACE_PRINTKS() __start___trace_bprintk_fmt = .; \
- KEEP(*(__trace_printk_fmt)) /* Trace_printk fmt' pointer */ \
- __stop___trace_bprintk_fmt = .;
-#define TRACEPOINT_STR() __start___tracepoint_str = .; \
- KEEP(*(__tracepoint_str)) /* Trace_printk fmt' pointer */ \
- __stop___tracepoint_str = .;
+#define TRACE_PRINTKS() BOUNDED_SECTION_BY(__trace_printk_fmt, ___trace_bprintk_fmt)
+#define TRACEPOINT_STR() BOUNDED_SECTION_BY(__tracepoint_str, ___tracepoint_str)
#else
#define TRACE_PRINTKS()
#define TRACEPOINT_STR()
#endif

#ifdef CONFIG_FTRACE_SYSCALLS
-#define TRACE_SYSCALLS() . = ALIGN(8); \
- __start_syscalls_metadata = .; \
- KEEP(*(__syscalls_metadata)) \
- __stop_syscalls_metadata = .;
+#define TRACE_SYSCALLS() \
+ . = ALIGN(8); \
+ BOUNDED_SECTION_BY(__syscalls_metadata, _syscalls_metadata)
#else
#define TRACE_SYSCALLS()
#endif

#ifdef CONFIG_BPF_EVENTS
-#define BPF_RAW_TP() STRUCT_ALIGN(); \
- __start__bpf_raw_tp = .; \
- KEEP(*(__bpf_raw_tp_map)) \
- __stop__bpf_raw_tp = .;
+#define BPF_RAW_TP() STRUCT_ALIGN(); \
+ BOUNDED_SECTION_BY(__bpf_raw_tp_map, __bpf_raw_tp)
#else
#define BPF_RAW_TP()
#endif

#ifdef CONFIG_SERIAL_EARLYCON
-#define EARLYCON_TABLE() . = ALIGN(8); \
- __earlycon_table = .; \
- KEEP(*(__earlycon_table)) \
- __earlycon_table_end = .;
+#define EARLYCON_TABLE() \
+ . = ALIGN(8); \
+ BOUNDED_SECTION_POST_LABEL(__earlycon_table, __earlycon_table, , _end)
#else
#define EARLYCON_TABLE()
#endif

#ifdef CONFIG_SECURITY
-#define LSM_TABLE() . = ALIGN(8); \
- __start_lsm_info = .; \
- KEEP(*(.lsm_info.init)) \
- __end_lsm_info = .;
-#define EARLY_LSM_TABLE() . = ALIGN(8); \
- __start_early_lsm_info = .; \
- KEEP(*(.early_lsm_info.init)) \
- __end_early_lsm_info = .;
+#define LSM_TABLE() \
+ . = ALIGN(8); \
+ BOUNDED_SECTION_PRE_LABEL(.lsm_info.init, _lsm_info, __start, __end)
+
+#define EARLY_LSM_TABLE() \
+ . = ALIGN(8); \
+ BOUNDED_SECTION_PRE_LABEL(.early_lsm_info.init, _early_lsm_info, __start, __end)
#else
#define LSM_TABLE()
#define EARLY_LSM_TABLE()
@@ -312,9 +311,8 @@
#ifdef CONFIG_ACPI
#define ACPI_PROBE_TABLE(name) \
. = ALIGN(8); \
- __##name##_acpi_probe_table = .; \
- KEEP(*(__##name##_acpi_probe_table)) \
- __##name##_acpi_probe_table_end = .;
+ BOUNDED_SECTION_POST_LABEL(__##name##_acpi_probe_table, \
+ __##name##_acpi_probe_table,, _end)
#else
#define ACPI_PROBE_TABLE(name)
#endif
@@ -322,9 +320,8 @@
#ifdef CONFIG_THERMAL
#define THERMAL_TABLE(name) \
. = ALIGN(8); \
- __##name##_thermal_table = .; \
- KEEP(*(__##name##_thermal_table)) \
- __##name##_thermal_table_end = .;
+ BOUNDED_SECTION_POST_LABEL(__##name##_thermal_table, \
+ __##name##_thermal_table,, _end)
#else
#define THERMAL_TABLE(name)
#endif
@@ -353,12 +350,8 @@
*(__tracepoints) \
/* implement dynamic printk debug */ \
. = ALIGN(8); \
- __start___dyndbg_classes = .; \
- KEEP(*(__dyndbg_classes)) \
- __stop___dyndbg_classes = .; \
- __start___dyndbg = .; \
- KEEP(*(__dyndbg)) \
- __stop___dyndbg = .; \
+ BOUNDED_SECTION_BY(__dyndbg_classes, ___dyndbg_classes) \
+ BOUNDED_SECTION_BY(__dyndbg, ___dyndbg) \
LIKELY_PROFILE() \
BRANCH_PROFILE() \
TRACE_PRINTKS() \
@@ -401,19 +394,13 @@

#define JUMP_TABLE_DATA \
. = ALIGN(8); \
- __start___jump_table = .; \
- KEEP(*(__jump_table)) \
- __stop___jump_table = .;
+ BOUNDED_SECTION_BY(__jump_table, ___jump_table)

#ifdef CONFIG_HAVE_STATIC_CALL_INLINE
#define STATIC_CALL_DATA \
. = ALIGN(8); \
- __start_static_call_sites = .; \
- KEEP(*(.static_call_sites)) \
- __stop_static_call_sites = .; \
- __start_static_call_tramp_key = .; \
- KEEP(*(.static_call_tramp_key)) \
- __stop_static_call_tramp_key = .;
+ BOUNDED_SECTION_BY(.static_call_sites, _static_call_sites) \
+ BOUNDED_SECTION_BY(.static_call_tramp_key, _static_call_tramp_key)
#else
#define STATIC_CALL_DATA
#endif
@@ -439,9 +426,7 @@
#ifdef CONFIG_ARCH_USES_CFI_TRAPS
#define KCFI_TRAPS \
__kcfi_traps : AT(ADDR(__kcfi_traps) - LOAD_OFFSET) { \
- __start___kcfi_traps = .; \
- KEEP(*(.kcfi_traps)) \
- __stop___kcfi_traps = .; \
+ BOUNDED_SECTION_BY(.kcfi_traps, ___kcfi_traps) \
}
#else
#define KCFI_TRAPS
@@ -459,9 +444,7 @@
SCHED_DATA \
RO_AFTER_INIT_DATA /* Read only after init */ \
. = ALIGN(8); \
- __start___tracepoints_ptrs = .; \
- KEEP(*(__tracepoints_ptrs)) /* Tracepoints: pointer array */ \
- __stop___tracepoints_ptrs = .; \
+ BOUNDED_SECTION_BY(__tracepoints_ptrs, ___tracepoints_ptrs) \
*(__tracepoints_strings)/* Tracepoints: strings */ \
} \
\
@@ -471,30 +454,14 @@
\
/* PCI quirks */ \
.pci_fixup : AT(ADDR(.pci_fixup) - LOAD_OFFSET) { \
- __start_pci_fixups_early = .; \
- KEEP(*(.pci_fixup_early)) \
- __end_pci_fixups_early = .; \
- __start_pci_fixups_header = .; \
- KEEP(*(.pci_fixup_header)) \
- __end_pci_fixups_header = .; \
- __start_pci_fixups_final = .; \
- KEEP(*(.pci_fixup_final)) \
- __end_pci_fixups_final = .; \
- __start_pci_fixups_enable = .; \
- KEEP(*(.pci_fixup_enable)) \
- __end_pci_fixups_enable = .; \
- __start_pci_fixups_resume = .; \
- KEEP(*(.pci_fixup_resume)) \
- __end_pci_fixups_resume = .; \
- __start_pci_fixups_resume_early = .; \
- KEEP(*(.pci_fixup_resume_early)) \
- __end_pci_fixups_resume_early = .; \
- __start_pci_fixups_suspend = .; \
- KEEP(*(.pci_fixup_suspend)) \
- __end_pci_fixups_suspend = .; \
- __start_pci_fixups_suspend_late = .; \
- KEEP(*(.pci_fixup_suspend_late)) \
- __end_pci_fixups_suspend_late = .; \
+ BOUNDED_SECTION_PRE_LABEL(.pci_fixup_early, _pci_fixups_early, __start, __end) \
+ BOUNDED_SECTION_PRE_LABEL(.pci_fixup_header, _pci_fixups_header, __start, __end) \
+ BOUNDED_SECTION_PRE_LABEL(.pci_fixup_final, _pci_fixups_final, __start, __end) \
+ BOUNDED_SECTION_PRE_LABEL(.pci_fixup_enable, _pci_fixups_enable, __start, __end) \
+ BOUNDED_SECTION_PRE_LABEL(.pci_fixup_resume, _pci_fixups_resume, __start, __end) \
+ BOUNDED_SECTION_PRE_LABEL(.pci_fixup_suspend, _pci_fixups_suspend, __start, __end) \
+ BOUNDED_SECTION_PRE_LABEL(.pci_fixup_resume_early, _pci_fixups_resume_early, __start, __end) \
+ BOUNDED_SECTION_PRE_LABEL(.pci_fixup_suspend_late, _pci_fixups_suspend_late, __start, __end) \
} \
\
FW_LOADER_BUILT_IN_DATA \
@@ -544,16 +511,12 @@
\
/* Built-in module parameters. */ \
__param : AT(ADDR(__param) - LOAD_OFFSET) { \
- __start___param = .; \
- KEEP(*(__param)) \
- __stop___param = .; \
+ BOUNDED_SECTION_BY(__param, ___param) \
} \
\
/* Built-in module versions. */ \
__modver : AT(ADDR(__modver) - LOAD_OFFSET) { \
- __start___modver = .; \
- KEEP(*(__modver)) \
- __stop___modver = .; \
+ BOUNDED_SECTION_BY(__modver, ___modver) \
} \
\
KCFI_TRAPS \
@@ -663,9 +626,7 @@
#define EXCEPTION_TABLE(align) \
. = ALIGN(align); \
__ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) { \
- __start___ex_table = .; \
- KEEP(*(__ex_table)) \
- __stop___ex_table = .; \
+ BOUNDED_SECTION_BY(__ex_table, ___ex_table) \
}

/*
@@ -674,9 +635,7 @@
#ifdef CONFIG_DEBUG_INFO_BTF
#define BTF \
.BTF : AT(ADDR(.BTF) - LOAD_OFFSET) { \
- __start_BTF = .; \
- KEEP(*(.BTF)) \
- __stop_BTF = .; \
+ BOUNDED_SECTION_BY(.BTF, _BTF) \
} \
. = ALIGN(4); \
.BTF_ids : AT(ADDR(.BTF_ids) - LOAD_OFFSET) { \
@@ -853,9 +812,7 @@
#define BUG_TABLE \
. = ALIGN(8); \
__bug_table : AT(ADDR(__bug_table) - LOAD_OFFSET) { \
- __start___bug_table = .; \
- KEEP(*(__bug_table)) \
- __stop___bug_table = .; \
+ BOUNDED_SECTION_BY(__bug_table, ___bug_table) \
}
#else
#define BUG_TABLE
@@ -865,15 +822,11 @@
#define ORC_UNWIND_TABLE \
. = ALIGN(4); \
.orc_unwind_ip : AT(ADDR(.orc_unwind_ip) - LOAD_OFFSET) { \
- __start_orc_unwind_ip = .; \
- KEEP(*(.orc_unwind_ip)) \
- __stop_orc_unwind_ip = .; \
+ BOUNDED_SECTION_BY(.orc_unwind_ip, _orc_unwind_ip) \
} \
. = ALIGN(2); \
.orc_unwind : AT(ADDR(.orc_unwind) - LOAD_OFFSET) { \
- __start_orc_unwind = .; \
- KEEP(*(.orc_unwind)) \
- __stop_orc_unwind = .; \
+ BOUNDED_SECTION_BY(.orc_unwind, _orc_unwind) \
} \
text_size = _etext - _stext; \
. = ALIGN(4); \
@@ -891,9 +844,7 @@
#ifdef CONFIG_FW_LOADER
#define FW_LOADER_BUILT_IN_DATA \
.builtin_fw : AT(ADDR(.builtin_fw) - LOAD_OFFSET) ALIGN(8) { \
- __start_builtin_fw = .; \
- KEEP(*(.builtin_fw)) \
- __end_builtin_fw = .; \
+ BOUNDED_SECTION_PRE_LABEL(.builtin_fw, _builtin_fw, __start, __end) \
}
#else
#define FW_LOADER_BUILT_IN_DATA
@@ -903,9 +854,7 @@
#define TRACEDATA \
. = ALIGN(4); \
.tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) { \
- __tracedata_start = .; \
- KEEP(*(.tracedata)) \
- __tracedata_end = .; \
+ BOUNDED_SECTION_POST_LABEL(.tracedata, __tracedata, _start, _end) \
}
#else
#define TRACEDATA
@@ -914,9 +863,7 @@
#ifdef CONFIG_PRINTK_INDEX
#define PRINTK_INDEX \
.printk_index : AT(ADDR(.printk_index) - LOAD_OFFSET) { \
- __start_printk_index = .; \
- *(.printk_index) \
- __stop_printk_index = .; \
+ BOUNDED_SECTION_BY(.printk_index, _printk_index) \
}
#else
#define PRINTK_INDEX
@@ -924,17 +871,13 @@

#define NOTES \
.notes : AT(ADDR(.notes) - LOAD_OFFSET) { \
- __start_notes = .; \
- KEEP(*(.note.*)) \
- __stop_notes = .; \
+ BOUNDED_SECTION_BY(.note.*, _notes) \
} NOTES_HEADERS \
NOTES_HEADERS_RESTORE

#define INIT_SETUP(initsetup_align) \
. = ALIGN(initsetup_align); \
- __setup_start = .; \
- KEEP(*(.init.setup)) \
- __setup_end = .;
+ BOUNDED_SECTION_POST_LABEL(.init.setup, __setup, _start, _end)

#define INIT_CALLS_LEVEL(level) \
__initcall##level##_start = .; \
@@ -956,16 +899,12 @@
__initcall_end = .;

#define CON_INITCALL \
- __con_initcall_start = .; \
- KEEP(*(.con_initcall.init)) \
- __con_initcall_end = .;
+ BOUNDED_SECTION_POST_LABEL(.con_initcall.init, __con_initcall, _start, _end)

/* Alignment must be consistent with (kunit_suite *) in include/kunit/test.h */
#define KUNIT_TABLE() \
. = ALIGN(8); \
- __kunit_suites_start = .; \
- KEEP(*(.kunit_test_suites)) \
- __kunit_suites_end = .;
+ BOUNDED_SECTION_POST_LABEL(.kunit_test_suites, __kunit_suites, _start, _end)

#ifdef CONFIG_BLK_DEV_INITRD
#define INIT_RAM_FS \
--
2.37.3