From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Alan Maguire <alan.maguire@oracle.com>
Cc: Jiri Olsa <jolsa@kernel.org>,
Clark Williams <williams@redhat.com>,
dwarves@vger.kernel.org, bpf@vger.kernel.org,
Andrii Nakryiko <andrii@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: [PATCH 31/31] btfdiff: Remove --flat_arrays now that pahole encodes multi dim arrays in BTF
Date: Wed, 29 Jul 2026 16:07:31 -0300 [thread overview]
Message-ID: <20260729190733.72876-32-acme@kernel.org> (raw)
In-Reply-To: <20260729190733.72876-1-acme@kernel.org>
From: Arnaldo Carvalho de Melo <acme@redhat.com>
With it, i.e. flattening DWARF arrays we get:
acme@number:~/git/build/v7.2-rc3+$ btfdiff vmlinux
--- /tmp/btfdiff.dwarf.sXVla7 2026-07-16 18:53:09.744346444 -0300
+++ /tmp/btfdiff.btf.uzBSIz 2026-07-16 18:53:04.975270734 -0300
@@ -21905,7 +21905,7 @@ struct amd_iommu {
/* typedef u32 -> __u32 */ unsigned int stored_addr_lo; /* 336 4 */
/* typedef u32 -> __u32 */ unsigned int stored_addr_hi; /* 340 4 */
- /* typedef u32 -> __u32 */ unsigned int stored_l1[108]; /* 344 432 */
+ /* typedef u32 -> __u32 */ unsigned int stored_l1[6][18]; /* 344 432 */
/* --- cacheline 12 boundary (768 bytes) was 8 bytes ago --- */
/* typedef u32 -> __u32 */ unsigned int stored_l2[131]; /* 776 524 */
/* --- cacheline 20 boundary (1280 bytes) was 20 bytes ago --- */
@@ -22489,7 +22489,7 @@ struct amd_mdb_pcie {
/* --- cacheline 6 boundary (384 bytes) --- */
struct pci_eq_presets {
/* typedef u16 -> __u16 */ short unsigned int eq_presets_8gts[16]; /* 384 32 */
- /* typedef u8 -> __u8 */ unsigned char eq_presets_Ngts[48]; /* 416 48 */
+ /* typedef u8 -> __u8 */ unsigned char eq_presets_Ngts[3][16]; /* 416 48 */
} presets; /* 384 80 */
/* --- cacheline 7 boundary (448 bytes) was 16 bytes ago --- */
struct pci_config_window * cfg; /* 464 8 */
@@ -29007,7 +29007,7 @@ struct audit_aux_data_pids {
} bpf; /* 296 4 */
} target_ref[16]; /* 272 512 */
/* --- cacheline 12 boundary (768 bytes) was 16 bytes ago --- */
- char target_comm[256]; /* 784 256 */
+ char target_comm[16][16]; /* 784 256 */
/* --- cacheline 16 boundary (1024 bytes) was 16 bytes ago --- */
int pid_count; /* 1040 4 */
@@ -30613,7 +30613,7 @@ struct automaton_nomiss {
char * event_names[7]; /* 40 56 */
/* --- cacheline 1 boundary (64 bytes) was 32 bytes ago --- */
char * env_names[3]; /* 96 24 */
- unsigned char function[35]; /* 120 35 */
+ unsigned char function[5][7]; /* 120 35 */
/* --- cacheline 2 boundary (128 bytes) was 27 bytes ago --- */
unsigned char initial_state; /* 155 1 */
/* typedef bool */ _Bool final_states[5]; /* 156 5 */
@@ -30627,7 +30627,7 @@ struct automaton_stall {
char * event_names[4]; /* 24 32 */
char * env_names[1]; /* 56 8 */
/* --- cacheline 1 boundary (64 bytes) --- */
- unsigned char function[12]; /* 64 12 */
+ unsigned char function[3][4]; /* 64 12 */
unsigned char initial_state; /* 76 1 */
/* typedef bool */ _Bool final_states[3]; /* 77 3 */
@@ -30637,7 +30637,7 @@ struct automaton_stall {
struct automaton_wip {
char * state_names[2]; /* 0 16 */
char * event_names[3]; /* 16 24 */
- unsigned char function[6]; /* 40 6 */
+ unsigned char function[2][3]; /* 40 6 */
unsigned char initial_state; /* 46 1 */
/* typedef bool */ _Bool final_states[2]; /* 47 2 */
@@ -30648,7 +30648,7 @@ struct automaton_wip {
struct automaton_wwnr {
char * state_names[2]; /* 0 16 */
char * event_names[3]; /* 16 24 */
- unsigned char function[6]; /* 40 6 */
+ unsigned char function[2][3]; /* 40 6 */
unsigned char initial_state; /* 46 1 */
/* typedef bool */ _Bool final_states[2]; /* 47 2 */
@@ -136221,7 +136221,7 @@ struct dw_pcie {
/* --- cacheline 6 boundary (384 bytes) --- */
struct pci_eq_presets {
/* typedef u16 -> __u16 */ short unsigned int eq_presets_8gts[16]; /* 384 32 */
- /* typedef u8 -> __u8 */ unsigned char eq_presets_Ngts[48]; /* 416 48 */
+ /* typedef u8 -> __u8 */ unsigned char eq_presets_Ngts[3][16]; /* 416 48 */
} presets; /* 384 80 */
/* --- cacheline 7 boundary (448 bytes) was 16 bytes ago --- */
struct pci_config_window * cfg; /* 464 8 */
@@ -136582,7 +136582,7 @@ struct dw_pcie_rp {
struct pci_eq_presets {
/* typedef u16 -> __u16 */ short unsigned int eq_presets_8gts[16]; /* 288 32 */
/* --- cacheline 5 boundary (320 bytes) --- */
- /* typedef u8 -> __u8 */ unsigned char eq_presets_Ngts[48]; /* 320 48 */
+ /* typedef u8 -> __u8 */ unsigned char eq_presets_Ngts[3][16]; /* 320 48 */
} presets; /* 288 80 */
struct pci_config_window * cfg; /* 368 8 */
/* typedef bool */ _Bool ecam_enabled; /* 376 1 */
@@ -173280,7 +173280,7 @@ struct fu740_pcie {
/* --- cacheline 6 boundary (384 bytes) --- */
struct pci_eq_presets {
/* typedef u16 -> __u16 */ short unsigned int eq_presets_8gts[16]; /* 384 32 */
- /* typedef u8 -> __u8 */ unsigned char eq_presets_Ngts[48]; /* 416 48 */
+ /* typedef u8 -> __u8 */ unsigned char eq_presets_Ngts[3][16]; /* 416 48 */
} presets; /* 384 80 */
/* --- cacheline 7 boundary (448 bytes) was 16 bytes ago --- */
struct pci_config_window * cfg; /* 464 8 */
@@ -191392,10 +191392,10 @@ struct hugetlb_cgroup {
/* --- cacheline 832 boundary (53248 bytes) --- */
/* typedef atomic_long_t -> atomic64_t */ struct {
/* typedef s64 -> __s64 */ long long int counter; /* 53248 8 */
- } events[2]; /* 53248 16 */
+ } events[2][1]; /* 53248 16 */
/* typedef atomic_long_t -> atomic64_t */ struct {
/* typedef s64 -> __s64 */ long long int counter; /* 53264 8 */
- } events_local[2]; /* 53264 16 */
+ } events_local[2][1]; /* 53264 16 */
struct cgroup_file {
struct kernfs_node * kn; /* 53280 8 */
long unsigned int notified_at; /* 53288 8 */
@@ -234492,7 +234492,7 @@ struct intel_pcie {
/* --- cacheline 6 boundary (384 bytes) --- */
struct pci_eq_presets {
/* typedef u16 -> __u16 */ short unsigned int eq_presets_8gts[16]; /* 384 32 */
- /* typedef u8 -> __u8 */ unsigned char eq_presets_Ngts[48]; /* 416 48 */
+ /* typedef u8 -> __u8 */ unsigned char eq_presets_Ngts[3][16]; /* 416 48 */
} presets; /* 384 80 */
/* --- cacheline 7 boundary (448 bytes) was 16 bytes ago --- */
struct pci_config_window * cfg; /* 464 8 */
@@ -263257,7 +263257,7 @@ struct keembay_pcie {
/* --- cacheline 6 boundary (384 bytes) --- */
struct pci_eq_presets {
/* typedef u16 -> __u16 */ short unsigned int eq_presets_8gts[16]; /* 384 32 */
- /* typedef u8 -> __u8 */ unsigned char eq_presets_Ngts[48]; /* 416 48 */
+ /* typedef u8 -> __u8 */ unsigned char eq_presets_Ngts[3][16]; /* 416 48 */
} presets; /* 384 80 */
/* --- cacheline 7 boundary (448 bytes) was 16 bytes ago --- */
struct pci_config_window * cfg; /* 464 8 */
<Big SNIP>
@@ -617956,14 +617956,14 @@ struct xz_dec_microlzma {
struct lzma_len_dec {
/* typedef uint16_t -> u16 -> __u16 */ short unsigned int choice; /* 2824 2 */
/* typedef uint16_t -> u16 -> __u16 */ short unsigned int choice2; /* 2826 2 */
- /* typedef uint16_t -> u16 -> __u16 */ short unsigned int low[128]; /* 2828 256 */
+ /* typedef uint16_t -> u16 -> __u16 */ short unsigned int low[16][8]; /* 2828 256 */
/* --- cacheline 48 boundary (3072 bytes) was 12 bytes ago --- */
- /* typedef uint16_t -> u16 -> __u16 */ short unsigned int mid[128]; /* 3084 256 */
+ /* typedef uint16_t -> u16 -> __u16 */ short unsigned int mid[16][8]; /* 3084 256 */
/* --- cacheline 52 boundary (3328 bytes) was 12 bytes ago --- */
/* typedef uint16_t -> u16 -> __u16 */ short unsigned int high[256]; /* 3340 512 */
} rep_len_dec; /* 2824 1028 */
/* --- cacheline 60 boundary (3840 bytes) was 12 bytes ago --- */
- /* typedef uint16_t -> u16 -> __u16 */ short unsigned int literal[12288]; /* 3852 24576 */
+ /* typedef uint16_t -> u16 -> __u16 */ short unsigned int literal[16][768]; /* 3852 24576 */
} lzma; /* 124 28304 */
/* --- cacheline 444 boundary (28416 bytes) was 12 bytes ago --- */
struct {
Now, removing --flat_arrays makes it clean, meaning both DWARF and BTF
loaders support multi dimensional arrays and so does the BTF encoder.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
btfdiff | 1 -
1 file changed, 1 deletion(-)
diff --git a/btfdiff b/btfdiff
index 46348f46a08c50ab..18794dfd3e1562d4 100755
--- a/btfdiff
+++ b/btfdiff
@@ -24,7 +24,6 @@ dwarf_output=$(mktemp /tmp/btfdiff.dwarf.XXXXXX)
pahole_bin=${PAHOLE-"pahole"}
${pahole_bin} -E -F dwarf \
- --flat_arrays \
--sort \
--jobs \
--suppress_aligned_attribute \
--
2.55.0
prev parent reply other threads:[~2026-07-29 19:08 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-29 19:07 [PATCHES 00/31] pahole: Bug fixes and small improvements Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 01/31] cmake: Update minimum required version from 3.5 to 3.10 Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 02/31] Fix -Wsign-compare warnings across the codebase Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 03/31] btf_encoder: Fix interior pointer free and missing NULL check Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 04/31] dwarves: Fix missing list head initialization in type__clone_members Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 05/31] pahole: Fix instance memory leak on early returns in prototype__stdio_fprintf_value Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 06/31] ctf_loader, libctf: Fix error path resource leaks Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 07/31] dwarves: Don't search for holes before member byte sizes are cached Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 08/31] dwarf_loader: Allocate type_dcu via dwarf_cu__new to fix dangling stack pointer Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 09/31] dwarf_loader: Fix annotation failure leaks in variable and typedef creation Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 10/31] btf_encoder: Use btf_encoder__tag_type() for all type ID computations Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 11/31] pahole: Fix --errno typo that decrements instead of negating Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 12/31] dwarves: Fix heap buffer overflow in languages__parse realloc Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 13/31] btf_encoder: Fix early cleanup crashes in btf_encoder__new/delete Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 14/31] btf_encoder, libctf: Add elf_strptr NULL checks and fix kfunc bounds Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 15/31] dwarf_loader: Fix --fixup_silly_bitfields condition check Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 16/31] dwarf_loader: Skip libdw__lock when elfutils is built thread-safe Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 17/31] dwarf_loader: Fix data race in tag__init() decl_file string cache Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 18/31] pahole: Fix parse_btf_features("all") being a silent no-op Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 19/31] dwarves: Fix variable shadowing in __cus__find_struct_by_name() Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 20/31] dutil: Add exec_objcopy() shell-injection-safe helper Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 21/31] btf_encoder: Fall back to objcopy when llvm-objcopy is not available Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 22/31] dwarf_loader, btf_loader: Replace stale FIXME/XXX comments with explanations Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 23/31] pahole: Skip inline expansions during BTF encoding Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 24/31] pahole: Use fseek for seekable files in --prettify and --seek_bytes Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 25/31] pahole: Guard pipe_seek() against negative offsets Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 26/31] gobuffer: Remove 5 dead functions found via coverage analysis Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 27/31] dwarves: Remove 6 " Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 28/31] pfunct, dwarves_fprintf: Mark file-local functions as static Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 29/31] btf_encoder: Fix multi-dimensional array encoding Arnaldo Carvalho de Melo
2026-07-29 19:07 ` [PATCH 30/31] btf_loader: Fix multi-dimensional array loading Arnaldo Carvalho de Melo
2026-07-29 19:07 ` Arnaldo Carvalho de Melo [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260729190733.72876-32-acme@kernel.org \
--to=acme@kernel.org \
--cc=acme@redhat.com \
--cc=alan.maguire@oracle.com \
--cc=andrii@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=dwarves@vger.kernel.org \
--cc=jolsa@kernel.org \
--cc=williams@redhat.com \
--cc=yonghong.song@linux.dev \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.