[Bug gas/27411] New: [ARM] Wrong error message when assembler cannot honor width suffix ("lo register required")
https://sourceware.org/bugzilla/show_bug.cgi?id=27411
Bug ID: 27411
Summary: [ARM] Wrong error message when assembler cannot honor
width suffix ("lo register required")
Product: binutils
Version: 2.35.1
Status: UNCONFIRMED
Severity: minor
Priority: P2
Component: gas
Assignee: unassigned at sourceware dot org
Reporter: kordalski.wojciech at gmail dot com
Target Milestone: ---
Created attachment 13223
--> https://sourceware.org/bugzilla/attachment.cgi?id=13223&action=edit
Code that generates wrong assembler error message
For some instructions GAS returns wrong error message.
Code:
```
.syntax unified
.thumb
.align 2
.type f1, %function
.thumb_func
f1:
add.n r4, #8
```
gives error message:
test.s:8: Error: lo register required -- `add.n r4,#8'
Same for `sub.n` instruction.
The right error message would be the one returned for `lsl.n` instruction:
test.s:8: Error: cannot honor width suffix -- `lsl.n r4,#8'
--
You are receiving this mail because:
You are on the CC list for the bug.
[Bug gas/27412] New: Suspicious "setting incorrect section attributes for .note.Linux" warnings on linux kernel
https://sourceware.org/bugzilla/show_bug.cgi?id=27412
Bug ID: 27412
Summary: Suspicious "setting incorrect section attributes for
.note.Linux" warnings on linux kernel
Product: binutils
Version: unspecified
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: gas
Assignee: unassigned at sourceware dot org
Reporter: slyfox at inbox dot ru
CC: amodra at gmail dot com, hjl.tools at gmail dot com
Target Milestone: ---
When building current linux-5.10 (or master) with gcc-11/binutins-2.36 gas
complains about incorrect (used) section flags. Minimal reproducer:
$ cat bug.c
static const int _note_55 __attribute__((__used__))
__attribute__((section(".note.Linux"))) = 42;
$ gcc-11.0.0 -c bug.c -o bug-11.o -fno-ident
/tmp/ccJ9p7TD.s: Assembler messages:
/tmp/ccJ9p7TD.s:3: Warning: setting incorrect section attributes for
.note.Linux
$ gcc-10.2.0 -c bug.c -o bug-11.o -fno-ident
gcc-11 generates the following code:
$ gcc-11.0.0 -S bug.c -o bug-11.s -fno-ident && cat bug-11.s
.file "bug.c"
.text
.section.note.Linux,"aR"
.align 4
.type _note_55, @object
.size _note_55, 4
_note_55:
.long 42
.section.note.GNU-stack,"",@progbits
gcc-10 for completeness:
$ gcc-10.2.0 -S bug.c -o bug-11.s -fno-ident && cat bug-11.s
.file "bug.c"
.text
.section.note.Linux,"a"
.align 4
.type _note_55, @object
.size _note_55, 4
_note_55:
.long 42
.section.note.GNU-stack,"",@progbits
Original code comes from:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/elfnote.h#n71
Is it a real problem or a false positive warning? Currently
gcc-11/binutils-2.36 generates kernels that can't load some modules and
complain about a bunch of orphan sections. I wonder if this warhing is related
and somehow affects future linking.
--
You are receiving this mail because:
You are on the CC list for the bug.
[Bug gas/27412] Suspicious "setting incorrect section attributes for .note.Linux" warnings on linux kernel
https://sourceware.org/bugzilla/show_bug.cgi?id=27412
H.J. Lu changed:
What|Removed |Added
Status|UNCONFIRMED |WAITING
Last reconfirmed||2021-02-13
Ever confirmed|0 |1
--- Comment #1 from H.J. Lu ---
(In reply to Sergei Trofimovich from comment #0)
> When building current linux-5.10 (or master) with gcc-11/binutins-2.36 gas
> complains about incorrect (used) section flags. Minimal reproducer:
>
> $ cat bug.c
> static const int _note_55 __attribute__((__used__))
> __attribute__((section(".note.Linux"))) = 42;
>
> $ gcc-11.0.0 -c bug.c -o bug-11.o -fno-ident
> /tmp/ccJ9p7TD.s: Assembler messages:
> /tmp/ccJ9p7TD.s:3: Warning: setting incorrect section attributes for
> .note.Linux
This is an assembler bug.
>
> Is it a real problem or a false positive warning? Currently
> gcc-11/binutils-2.36 generates kernels that can't load some modules and
> complain about a bunch of orphan sections. I wonder if this warhing is
> related and somehow affects future linking.
Please try:
https://github.com/hjl-tools/linux/commit/d97c4aeb041b756861bb16ee895e2616f4b4061a
--
You are receiving this mail because:
You are on the CC list for the bug.
[Bug gas/27412] Suspicious "setting incorrect section attributes for .note.Linux" warnings on linux kernel
https://sourceware.org/bugzilla/show_bug.cgi?id=27412
--- Comment #2 from Sergei Trofimovich ---
(In reply to H.J. Lu from comment #1)
> (In reply to Sergei Trofimovich from comment #0)
> > When building current linux-5.10 (or master) with gcc-11/binutins-2.36 gas
> > complains about incorrect (used) section flags. Minimal reproducer:
> >
> > $ cat bug.c
> > static const int _note_55 __attribute__((__used__))
> > __attribute__((section(".note.Linux"))) = 42;
> >
> > $ gcc-11.0.0 -c bug.c -o bug-11.o -fno-ident
> > /tmp/ccJ9p7TD.s: Assembler messages:
> > /tmp/ccJ9p7TD.s:3: Warning: setting incorrect section attributes for
> > .note.Linux
>
> This is an assembler bug.
Aha. I'll ignore the warning for now then.
> > Is it a real problem or a false positive warning? Currently
> > gcc-11/binutils-2.36 generates kernels that can't load some modules and
> > complain about a bunch of orphan sections. I wonder if this warhing is
> > related and somehow affects future linking.
> Please try:
>
> https://github.com/hjl-tools/linux/commit/
> d97c4aeb041b756861bb16ee895e2616f4b4061a
Did not help. More details of what I see:
When I try to load mei-me.ko kernel crashes in jump_labels init as if there are
no certain sections (maybe data sections?):
$ modprobe mei-me
$ dmesg
BUG: unable to handle page fault for address: c006eb90
#PF: supervisor write access in kernel mode
#PF: error_code(0x0003) - permissions violation
PGD 12840b067 P4D 12840b067 PUD 12840d067 PMD 100323067 PTE 80010178e161
Oops: 0003 [#1] PREEMPT SMP
CPU: 1 PID: 116 Comm: modprobe Not tainted 5.11.0-rc7-00091-g34add6d4b676 #209
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
?-20190711_202441-buildvm-armv7-10.arm.fedoraproject.org-2.fc31 04/01/2014
RIP: 0010:jump_label_add_module+0x1b4/0x280
Code: 00 48 8b 43 08 a8 02 0f 85 a7 00 00 00 48 83 e0 fc 48 c7 02 00 00 00 00
48 89 42 08 48 8b 43 08 83 e0 03 48 09 c2 48 83 ca 02 <48> 89 53 08 4d 89 6e 10
49 89 6e 08 48 8b 43 08 a8 02 74 6b 48 83
RSP: 0018:b48e001b7d88 EFLAGS: 00010282
RAX: RBX: c006eb88 RCX:
RDX: a43a802f53c2 RSI: a41d2cc8 RDI: a41d2cc8
RBP: c004d1f0 R08: 0001 R09: 0012
R10: 1000 R11: a43a816d9001 R12: c004d5b0
R13: c004ea00 R14: a43a802f53a0 R15: c004d1f8
FS: 019f53c0() GS:a43abbc8() knl GS:
CS: 0010 DS: ES: CR0: 80050033
CR2: c006eb90 CR3: 0001016fe003 CR4: 00060ee0
Call Trace:
jump_label_module_notify+0x53/0x90
blocking_notifier_call_chain_robust+0x6c/0xd0
load_module+0x58e/0x810
__do_sys_init_module+0x115/0x160
do_syscall_64+0x2d/0x70
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x55ce39
Code: 0c 00 b8 ca 00 00 00 0f 05 eb a5 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48
89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01
c3 48 c7 c1 e0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:7ffc3a5e37c8 EFLAGS: 0246 ORIG_RAX: 00af
RAX: ffda RBX: RCX: 0055ce39
RDX: 006042ca RSI: 00042078 RDI: 7fb66fff7010
RBP: 7fb66fff7010 R08: 01a0b890 R09: 00042078
R10: 0007 R11: 0246 R12: 006042ca
R13: R14: 01a08054 R15: 7fb66ffd6ad0
Modules linked in: mei_me(+) mei
CR2: c006eb90
---[ end trace d7a0c94b086625bf ]---
Seemingly related linker warnings are in form of:
...
x86_64-pc-linux-gnu-ld: warning: orphan section `.data.event_kfree_skb' from
`net/core/net-traces.o' being placed in section `.data.event_kfree_skb'
x86_64-pc-linux-gnu-ld: warning: orphan section `.data.event_bpf_test_finish'
from `net/bpf/test_run.o' being placed in section `.data.event_bpf_test_finish'
x86_64-pc-linux-gnu-ld: warning: orphan section `.data.event_fib6_table_lookup'
from `net/ipv6/route.o' being placed in section `.data.event_fib6_table_lookup'
...
These appeared after gcc-10 switch. gcc-10 seems to be very eager at placing
things to their own sections:
Minimal example:
$ cat net-traces.c
struct s {
void *print_fmt;
};
struct s print_fmt_napi_poll[1];
__attribute__((__used__)) struct s event_napi_poll = {print_fmt_napi_poll};
Note the
.section.data.event_napi_poll,"awR"
vs
.data
in:
$ gcc-11.0.0 -fno-PIE -S net-traces.c -fno-ident && cat net-traces.s
.file "net-traces.c"
.text
.globl print_fmt_napi_poll
.bss
.align 8
.type print_fmt_napi_poll, @object
.size print_fmt_napi_poll, 8
print_fmt_napi_poll:
.zero 8
.globl event_napi_poll
.section.data.event_napi_poll,"awR"
.align 8
.type event_napi_poll, @object
.size event_napi_poll, 8
event_napi_poll:
.quad print_fmt_napi_poll
.section.note.GNU-stack
[Bug gas/27412] Suspicious "setting incorrect section attributes for .note.Linux" warnings on linux kernel
https://sourceware.org/bugzilla/show_bug.cgi?id=27412 H.J. Lu changed: What|Removed |Added Status|WAITING |NEW --- Comment #3 from H.J. Lu --- A patch is posted at https://sourceware.org/pipermail/binutils/2021-February/115343.html -- You are receiving this mail because: You are on the CC list for the bug.
[Bug gas/27412] Suspicious "setting incorrect section attributes for .note.Linux" warnings on linux kernel
https://sourceware.org/bugzilla/show_bug.cgi?id=27412 --- Comment #4 from Sergei Trofimovich --- (In reply to H.J. Lu from comment #3) > A patch is posted at > > https://sourceware.org/pipermail/binutils/2021-February/115343.html Works for me. Thank you! -- You are receiving this mail because: You are on the CC list for the bug.
[Bug gas/27415] New: eZ80 relocation computation fails unexpectedly
https://sourceware.org/bugzilla/show_bug.cgi?id=27415 Bug ID: 27415 Summary: eZ80 relocation computation fails unexpectedly Product: binutils Version: 2.36.1 Status: UNCONFIRMED Severity: normal Priority: P2 Component: gas Assignee: unassigned at sourceware dot org Reporter: stp+sw334 at bje dot id.au Target Milestone: --- The test case `z80_reloc.s` tests a variety of shift and mask expressions involving undefined symbols. Several expressions I would expect to work do not: .assume adl=1 ld hl, data24 >> 8 Should produce: 0: 21 00 00 00 ld hl,0x 1: r_word1 data24 Or possibly as r_byte1 and r_byte2 at 1: and 2: respectively. dw data24 >> 8 Should produce: 0: 00 00 0: r_word1 data24 Instead, these expressions result in an error: Error: invalid operands (*UND* and *ABS* sections) for `>>' This may be a documentation fault where `BFD_RELOC_Z80_WORD1` is described as "Highest 16 bits of multibyte (32 or 24 bit) value.", but is only used as the highest 16 bits of a 32 bit value. -- You are receiving this mail because: You are on the CC list for the bug.
