linux/include
Masahiro Yamada 0bfde8c9bb arch: fix broken BuildID for arm64 and riscv
commit 99cb0d917f upstream.

Dennis Gilmore reports that the BuildID is missing in the arm64 vmlinux
since commit 994b7ac169 ("arm64: remove special treatment for the
link order of head.o").

The issue is that the type of .notes section, which contains the BuildID,
changed from NOTES to PROGBITS.

Ard Biesheuvel figured out that whichever object gets linked first gets
to decide the type of a section. The PROGBITS type is the result of the
compiler emitting .note.GNU-stack as PROGBITS rather than NOTE.

While Ard provided a fix for arm64, I want to fix this globally because
the same issue is happening on riscv since commit 2348e6bf44 ("riscv:
remove special treatment for the link order of head.o"). This problem
will happen in general for other architectures if they start to drop
unneeded entries from scripts/head-object-list.txt.

Discard .note.GNU-stack in include/asm-generic/vmlinux.lds.h.

Link: https://lore.kernel.org/lkml/CAABkxwuQoz1CTbyb57n0ZX65eSYiTonFCU8-LCQc=74D=xE=rA@mail.gmail.com/
Fixes: 994b7ac169 ("arm64: remove special treatment for the link order of head.o")
Fixes: 2348e6bf44 ("riscv: remove special treatment for the link order of head.o")
Reported-by: Dennis Gilmore <dennis@ausil.us>
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
[Tom: stable backport 5.15.y, 5.10.y, 5.4.y]

Though the above "Fixes:" commits are not in this kernel, the conditions
which lead to a missing Build ID in arm64 vmlinux are similar.

Evidence points to these conditions:
1. ld version > 2.36 (exact binutils commit documented in a494398bde)
2. first object which gets linked (head.o) has a PROGBITS .note.GNU-stack segment

These conditions can be observed when:
- 5.15.60+ OR 5.10.136+ OR 5.4.210+
- AND ld version > 2.36
- AND arch=arm64
- AND CONFIG_MODVERSIONS=y

There are notable differences in the vmlinux elf files produced
before(bad) and after(good) applying this series.

Good: p_type:PT_NOTE segment exists.
 Bad: p_type:PT_NOTE segment is missing.

Good: sh_name_str:.notes section has sh_type:SHT_NOTE
 Bad: sh_name_str:.notes section has sh_type:SHT_PROGBITS

`readelf -n` (as of v2.40) searches for Build Id
by processing only the very first note in sh_type:SHT_NOTE sections.

This was previously bisected to the stable backport of 0d362be5b1.
Follow-up experiments were discussed here: https://lore.kernel.org/all/20221221235413.xaisboqmr7dkqwn6@oracle.com/
which strongly hints at condition 2.
Signed-off-by: Tom Saeger <tom.saeger@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 08:49:03 +01:00
..
acpi ACPI: APEI: Fix integer overflow in ghes_estatus_pool_init() 2022-11-10 18:15:34 +01:00
asm-generic arch: fix broken BuildID for arm64 and riscv 2023-03-17 08:49:03 +01:00
clocksource
crypto crypto: blake2s - remove shash module 2022-08-17 14:24:19 +02:00
drm drm/mipi-dsi: Fix byte order of 16-bit DCS set/get brightness 2023-03-10 09:39:24 +01:00
dt-bindings clk: imx8mn: rename vpu_pll to m7_alt_pll 2022-12-31 13:14:12 +01:00
keys
kunit
kvm
linux PCI: Add SolidRun vendor ID 2023-03-17 08:49:02 +01:00
math-emu
media media: dvbdev: fix build warning due to comments 2022-12-31 13:14:47 +01:00
memory memory: renesas-rpc-if: Fix HF/OSPI data transfer in Manual Mode 2022-05-09 09:14:34 +02:00
misc
net netfilter: tproxy: fix deadlock due to missing BH disable 2023-03-17 08:48:55 +01:00
pcmcia
ras Revert "mm/memory-failure.c: fix race with changing page compound again" 2022-07-12 16:35:17 +02:00
rdma RDMA/netlink: Add __maybe_unused to static inline in C file 2021-11-25 09:49:07 +01:00
scsi scsi: iscsi_tcp: Fix UAF during logout when accessing the shost ipaddress 2023-02-09 11:26:39 +01:00
soc ARM: at91: pm: avoid soft resetting AC DLL 2022-11-26 09:24:34 +01:00
sound ASoC: soc-dapm.h: fixup warning struct snd_pcm_substream not declared 2023-03-10 09:39:31 +01:00
target scsi: target: Fix ordered tag handling 2021-11-25 09:48:29 +01:00
trace tracing: Use alignof__(struct {type b;}) instead of offsetof() 2023-01-24 07:22:48 +01:00
uapi usb: uvc: Enumerate valid values for color matching 2023-03-11 13:57:37 +01:00
vdso
video video: of_display_timing.h: include errno.h 2022-07-12 16:35:10 +02:00
xen xen/gnttab: fix gnttab_end_foreign_access() without page specified 2022-03-11 12:22:37 +01:00