* Re: [PATCH bpf-next v3 3/6] bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME
[not found] ` <20251118123639.688444-4-dongml2@chinatelecom.cn>
@ 2025-12-18 14:45 ` Andreas Schwab
2025-12-18 15:05 ` Menglong Dong
2025-12-19 2:22 ` Menglong Dong
0 siblings, 2 replies; 10+ messages in thread
From: Andreas Schwab @ 2025-12-18 14:45 UTC (permalink / raw)
To: Menglong Dong
Cc: ast, rostedt, daniel, john.fastabend, andrii, martin.lau, eddyz87,
song, yonghong.song, kpsingh, sdf, haoluo, jolsa, mhiramat,
mark.rutland, mathieu.desnoyers, jiang.biao, bpf, linux-kernel,
linux-trace-kernel, linux-riscv
On Nov 18 2025, Menglong Dong wrote:
> Some places calculate the origin_call by checking if
> BPF_TRAMP_F_SKIP_FRAME is set. However, it should use
> BPF_TRAMP_F_ORIG_STACK for this propose. Just fix them.
>
> Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
> Acked-by: Alexei Starovoitov <ast@kernel.org>
This breaks RISC-V:
[ 8.584381][ T1] systemd[1]: bpf-restrict-fs: LSM BPF program attached
[ 8.588359][ T1] Insufficient stack space to handle exception!
[ 8.588823][ T1] Task stack: [0xff20000000010000..0xff20000000014000]
[ 8.589219][ T1] Overflow stack: [0xff600000ffdad070..0xff600000ffdae070]
[ 8.590133][ T1] CPU: 1 UID: 0 PID: 1 Comm: systemd Not tainted 6.18.0-rc5+ #15 PREEMPT(voluntary) c900881ed1c1988ec5cf3e914d0edeb1b4d83ca3
[ 8.590898][ T1] Hardware name: riscv-virtio qemu/qemu, BIOS 2025.10 10/01/2025
[ 8.591494][ T1] epc : copy_from_kernel_nofault+0xa/0x198
[ 8.592292][ T1] ra : bpf_probe_read_kernel+0x20/0x60
[ 8.592658][ T1] epc : ffffffff802b732a ra : ffffffff801e6070 sp : ff2000000000ffe0
[ 8.593121][ T1] gp : ffffffff82262ed0 tp : 0000000000000000 t0 : ffffffff80022320
[ 8.593566][ T1] t1 : ffffffff801e6056 t2 : 0000000000000000 s0 : ff20000000010040
[ 8.593997][ T1] s1 : 0000000000000008 a0 : ff20000000010050 a1 : ff60000083b3d320
[ 8.594446][ T1] a2 : 0000000000000008 a3 : 0000000000000097 a4 : 0000000000000000
[ 8.594940][ T1] a5 : 0000000000000000 a6 : 0000000000000021 a7 : 0000000000000003
[ 8.595396][ T1] s2 : ff20000000010050 s3 : ff6000008459fc18 s4 : ff60000083b3d340
[ 8.595831][ T1] s5 : ff20000000010060 s6 : 0000000000000000 s7 : ff20000000013aa8
[ 8.596215][ T1] s8 : 0000000000000000 s9 : 0000000000008000 s10: 000000000058dcb0
[ 8.596641][ T1] s11: 000000000058dca7 t3 : 000000006925116d t4 : ff6000008090f026
[ 8.597065][ T1] t5 : 00007fff9b0cbaa8 t6 : 0000000000000016
[ 8.597363][ T1] status: 0000000200000120 badaddr: 0000000000000000 cause: 8000000000000005
[ 8.598033][ T1] Kernel panic - not syncing: Kernel stack overflow
[ 8.598597][ T1] CPU: 1 UID: 0 PID: 1 Comm: systemd Not tainted 6.18.0-rc5+ #15 PREEMPT(voluntary) c900881ed1c1988ec5cf3e914d0edeb1b4d83ca3
[ 8.599244][ T1] Hardware name: riscv-virtio qemu/qemu, BIOS 2025.10 10/01/2025
[ 8.599659][ T1] Call Trace:
[ 8.600117][ T1] [<ffffffff8001a1f8>] dump_backtrace+0x28/0x38
[ 8.600517][ T1] [<ffffffff80002502>] show_stack+0x3a/0x50
[ 8.600844][ T1] [<ffffffff800122be>] dump_stack_lvl+0x56/0x80
[ 8.601176][ T1] [<ffffffff80012300>] dump_stack+0x18/0x22
[ 8.601518][ T1] [<ffffffff80002abe>] vpanic+0xf6/0x328
[ 8.601819][ T1] [<ffffffff80002d2e>] panic+0x3e/0x40
[ 8.602088][ T1] [<ffffffff80019ef0>] handle_bad_stack+0x98/0xa0
[ 8.602395][ T1] [<ffffffff801e6070>] bpf_probe_read_kernel+0x20/0x60
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH bpf-next v3 3/6] bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME
2025-12-18 14:45 ` [PATCH bpf-next v3 3/6] bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME Andreas Schwab
@ 2025-12-18 15:05 ` Menglong Dong
2025-12-19 2:22 ` Menglong Dong
1 sibling, 0 replies; 10+ messages in thread
From: Menglong Dong @ 2025-12-18 15:05 UTC (permalink / raw)
To: Andreas Schwab
Cc: ast, rostedt, daniel, john.fastabend, andrii, martin.lau, eddyz87,
song, yonghong.song, kpsingh, sdf, haoluo, jolsa, mhiramat,
mark.rutland, mathieu.desnoyers, jiang.biao, bpf, linux-kernel,
linux-trace-kernel, linux-riscv
On Thu, Dec 18, 2025 at 10:45 PM Andreas Schwab <schwab@linux-m68k.org> wrote:
>
> On Nov 18 2025, Menglong Dong wrote:
>
> > Some places calculate the origin_call by checking if
> > BPF_TRAMP_F_SKIP_FRAME is set. However, it should use
> > BPF_TRAMP_F_ORIG_STACK for this propose. Just fix them.
> >
> > Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
> > Acked-by: Alexei Starovoitov <ast@kernel.org>
>
> This breaks RISC-V:
It's weird, as the 2 flags should be set together all the time
in RISC-V. Sorry that I'm already in bed, I'll check it tomorrow
morning.
Thanks!
Menglong Dong
>
> [ 8.584381][ T1] systemd[1]: bpf-restrict-fs: LSM BPF program attached
> [ 8.588359][ T1] Insufficient stack space to handle exception!
> [ 8.588823][ T1] Task stack: [0xff20000000010000..0xff20000000014000]
> [ 8.589219][ T1] Overflow stack: [0xff600000ffdad070..0xff600000ffdae070]
> [ 8.590133][ T1] CPU: 1 UID: 0 PID: 1 Comm: systemd Not tainted 6.18.0-rc5+ #15 PREEMPT(voluntary) c900881ed1c1988ec5cf3e914d0edeb1b4d83ca3
> [ 8.590898][ T1] Hardware name: riscv-virtio qemu/qemu, BIOS 2025.10 10/01/2025
> [ 8.591494][ T1] epc : copy_from_kernel_nofault+0xa/0x198
> [ 8.592292][ T1] ra : bpf_probe_read_kernel+0x20/0x60
> [ 8.592658][ T1] epc : ffffffff802b732a ra : ffffffff801e6070 sp : ff2000000000ffe0
> [ 8.593121][ T1] gp : ffffffff82262ed0 tp : 0000000000000000 t0 : ffffffff80022320
> [ 8.593566][ T1] t1 : ffffffff801e6056 t2 : 0000000000000000 s0 : ff20000000010040
> [ 8.593997][ T1] s1 : 0000000000000008 a0 : ff20000000010050 a1 : ff60000083b3d320
> [ 8.594446][ T1] a2 : 0000000000000008 a3 : 0000000000000097 a4 : 0000000000000000
> [ 8.594940][ T1] a5 : 0000000000000000 a6 : 0000000000000021 a7 : 0000000000000003
> [ 8.595396][ T1] s2 : ff20000000010050 s3 : ff6000008459fc18 s4 : ff60000083b3d340
> [ 8.595831][ T1] s5 : ff20000000010060 s6 : 0000000000000000 s7 : ff20000000013aa8
> [ 8.596215][ T1] s8 : 0000000000000000 s9 : 0000000000008000 s10: 000000000058dcb0
> [ 8.596641][ T1] s11: 000000000058dca7 t3 : 000000006925116d t4 : ff6000008090f026
> [ 8.597065][ T1] t5 : 00007fff9b0cbaa8 t6 : 0000000000000016
> [ 8.597363][ T1] status: 0000000200000120 badaddr: 0000000000000000 cause: 8000000000000005
> [ 8.598033][ T1] Kernel panic - not syncing: Kernel stack overflow
> [ 8.598597][ T1] CPU: 1 UID: 0 PID: 1 Comm: systemd Not tainted 6.18.0-rc5+ #15 PREEMPT(voluntary) c900881ed1c1988ec5cf3e914d0edeb1b4d83ca3
> [ 8.599244][ T1] Hardware name: riscv-virtio qemu/qemu, BIOS 2025.10 10/01/2025
> [ 8.599659][ T1] Call Trace:
> [ 8.600117][ T1] [<ffffffff8001a1f8>] dump_backtrace+0x28/0x38
> [ 8.600517][ T1] [<ffffffff80002502>] show_stack+0x3a/0x50
> [ 8.600844][ T1] [<ffffffff800122be>] dump_stack_lvl+0x56/0x80
> [ 8.601176][ T1] [<ffffffff80012300>] dump_stack+0x18/0x22
> [ 8.601518][ T1] [<ffffffff80002abe>] vpanic+0xf6/0x328
> [ 8.601819][ T1] [<ffffffff80002d2e>] panic+0x3e/0x40
> [ 8.602088][ T1] [<ffffffff80019ef0>] handle_bad_stack+0x98/0xa0
> [ 8.602395][ T1] [<ffffffff801e6070>] bpf_probe_read_kernel+0x20/0x60
>
> --
> Andreas Schwab, schwab@linux-m68k.org
> GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
> "And now for something completely different."
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH bpf-next v3 3/6] bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME
2025-12-18 14:45 ` [PATCH bpf-next v3 3/6] bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME Andreas Schwab
2025-12-18 15:05 ` Menglong Dong
@ 2025-12-19 2:22 ` Menglong Dong
2025-12-19 11:41 ` Andreas Schwab
1 sibling, 1 reply; 10+ messages in thread
From: Menglong Dong @ 2025-12-19 2:22 UTC (permalink / raw)
To: Menglong Dong, Andreas Schwab
Cc: ast, rostedt, daniel, john.fastabend, andrii, martin.lau, eddyz87,
song, yonghong.song, kpsingh, sdf, haoluo, jolsa, mhiramat,
mark.rutland, mathieu.desnoyers, jiang.biao, bpf, linux-kernel,
linux-trace-kernel, linux-riscv
On 2025/12/18 22:45 Andreas Schwab <schwab@linux-m68k.org> write:
> On Nov 18 2025, Menglong Dong wrote:
>
> > Some places calculate the origin_call by checking if
> > BPF_TRAMP_F_SKIP_FRAME is set. However, it should use
> > BPF_TRAMP_F_ORIG_STACK for this propose. Just fix them.
> >
> > Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
> > Acked-by: Alexei Starovoitov <ast@kernel.org>
>
> This breaks RISC-V:
Hi, Andreas. Can you offer more information here? After my analysis,
I didn't see the problem. BPF_TRAMP_F_SKIP_FRAME and
BPF_TRAMP_F_ORIG_STACK are set together all the time in RISC-V, so
I changed BPF_TRAMP_F_SKIP_FRAME to BPF_TRAMP_F_ORIG_STACK
*should* have no influence.
Thanks!
Menglong Dong
>
> [ 8.584381][ T1] systemd[1]: bpf-restrict-fs: LSM BPF program attached
> [ 8.588359][ T1] Insufficient stack space to handle exception!
> [ 8.588823][ T1] Task stack: [0xff20000000010000..0xff20000000014000]
> [ 8.589219][ T1] Overflow stack: [0xff600000ffdad070..0xff600000ffdae070]
> [ 8.590133][ T1] CPU: 1 UID: 0 PID: 1 Comm: systemd Not tainted 6.18.0-rc5+ #15 PREEMPT(voluntary) c900881ed1c1988ec5cf3e914d0edeb1b4d83ca3
> [ 8.590898][ T1] Hardware name: riscv-virtio qemu/qemu, BIOS 2025.10 10/01/2025
> [ 8.591494][ T1] epc : copy_from_kernel_nofault+0xa/0x198
> [ 8.592292][ T1] ra : bpf_probe_read_kernel+0x20/0x60
> [ 8.592658][ T1] epc : ffffffff802b732a ra : ffffffff801e6070 sp : ff2000000000ffe0
> [ 8.593121][ T1] gp : ffffffff82262ed0 tp : 0000000000000000 t0 : ffffffff80022320
> [ 8.593566][ T1] t1 : ffffffff801e6056 t2 : 0000000000000000 s0 : ff20000000010040
> [ 8.593997][ T1] s1 : 0000000000000008 a0 : ff20000000010050 a1 : ff60000083b3d320
> [ 8.594446][ T1] a2 : 0000000000000008 a3 : 0000000000000097 a4 : 0000000000000000
> [ 8.594940][ T1] a5 : 0000000000000000 a6 : 0000000000000021 a7 : 0000000000000003
> [ 8.595396][ T1] s2 : ff20000000010050 s3 : ff6000008459fc18 s4 : ff60000083b3d340
> [ 8.595831][ T1] s5 : ff20000000010060 s6 : 0000000000000000 s7 : ff20000000013aa8
> [ 8.596215][ T1] s8 : 0000000000000000 s9 : 0000000000008000 s10: 000000000058dcb0
> [ 8.596641][ T1] s11: 000000000058dca7 t3 : 000000006925116d t4 : ff6000008090f026
> [ 8.597065][ T1] t5 : 00007fff9b0cbaa8 t6 : 0000000000000016
> [ 8.597363][ T1] status: 0000000200000120 badaddr: 0000000000000000 cause: 8000000000000005
> [ 8.598033][ T1] Kernel panic - not syncing: Kernel stack overflow
> [ 8.598597][ T1] CPU: 1 UID: 0 PID: 1 Comm: systemd Not tainted 6.18.0-rc5+ #15 PREEMPT(voluntary) c900881ed1c1988ec5cf3e914d0edeb1b4d83ca3
> [ 8.599244][ T1] Hardware name: riscv-virtio qemu/qemu, BIOS 2025.10 10/01/2025
> [ 8.599659][ T1] Call Trace:
> [ 8.600117][ T1] [<ffffffff8001a1f8>] dump_backtrace+0x28/0x38
> [ 8.600517][ T1] [<ffffffff80002502>] show_stack+0x3a/0x50
> [ 8.600844][ T1] [<ffffffff800122be>] dump_stack_lvl+0x56/0x80
> [ 8.601176][ T1] [<ffffffff80012300>] dump_stack+0x18/0x22
> [ 8.601518][ T1] [<ffffffff80002abe>] vpanic+0xf6/0x328
> [ 8.601819][ T1] [<ffffffff80002d2e>] panic+0x3e/0x40
> [ 8.602088][ T1] [<ffffffff80019ef0>] handle_bad_stack+0x98/0xa0
> [ 8.602395][ T1] [<ffffffff801e6070>] bpf_probe_read_kernel+0x20/0x60
>
> --
> Andreas Schwab, schwab@linux-m68k.org
> GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
> "And now for something completely different."
>
>
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH bpf-next v3 3/6] bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME
2025-12-19 2:22 ` Menglong Dong
@ 2025-12-19 11:41 ` Andreas Schwab
2025-12-19 12:27 ` Menglong Dong
0 siblings, 1 reply; 10+ messages in thread
From: Andreas Schwab @ 2025-12-19 11:41 UTC (permalink / raw)
To: Menglong Dong
Cc: Menglong Dong, ast, rostedt, daniel, john.fastabend, andrii,
martin.lau, eddyz87, song, yonghong.song, kpsingh, sdf, haoluo,
jolsa, mhiramat, mark.rutland, mathieu.desnoyers, jiang.biao, bpf,
linux-kernel, linux-trace-kernel, linux-riscv
On Dez 19 2025, Menglong Dong wrote:
> BPF_TRAMP_F_ORIG_STACK
How can that ever be set?
if (flags & (BPF_TRAMP_F_ORIG_STACK | BPF_TRAMP_F_SHARE_IPMODIFY))
return -ENOTSUPP;
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH bpf-next v3 3/6] bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME
2025-12-19 11:41 ` Andreas Schwab
@ 2025-12-19 12:27 ` Menglong Dong
2025-12-19 13:31 ` Menglong Dong
0 siblings, 1 reply; 10+ messages in thread
From: Menglong Dong @ 2025-12-19 12:27 UTC (permalink / raw)
To: Andreas Schwab
Cc: Menglong Dong, ast, rostedt, daniel, john.fastabend, andrii,
martin.lau, eddyz87, song, yonghong.song, kpsingh, sdf, haoluo,
jolsa, mhiramat, mark.rutland, mathieu.desnoyers, jiang.biao, bpf,
linux-kernel, linux-trace-kernel, linux-riscv
On 2025/12/19 19:41, Andreas Schwab wrote:
> On Dez 19 2025, Menglong Dong wrote:
>
> > BPF_TRAMP_F_ORIG_STACK
>
> How can that ever be set?
Oops, my bad! It should be BPF_TRAMP_F_CALL_ORIG here. I think
it is some kind of copy-paste mistake. I'll send a fix for it.
Thanks!
Menglong Dong
>
> if (flags & (BPF_TRAMP_F_ORIG_STACK | BPF_TRAMP_F_SHARE_IPMODIFY))
> return -ENOTSUPP;
>
>
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^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH bpf-next v3 3/6] bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME
2025-12-19 12:27 ` Menglong Dong
@ 2025-12-19 13:31 ` Menglong Dong
2025-12-19 13:48 ` Andreas Schwab
0 siblings, 1 reply; 10+ messages in thread
From: Menglong Dong @ 2025-12-19 13:31 UTC (permalink / raw)
To: ast
Cc: Andreas Schwab, Menglong Dong, rostedt, daniel, john.fastabend,
andrii, martin.lau, eddyz87, song, yonghong.song, kpsingh, sdf,
haoluo, jolsa, mhiramat, mark.rutland, mathieu.desnoyers,
jiang.biao, bpf, linux-kernel, linux-trace-kernel, linux-riscv
On 2025/12/19 20:27, Menglong Dong wrote:
> On 2025/12/19 19:41, Andreas Schwab wrote:
> > On Dez 19 2025, Menglong Dong wrote:
> >
> > > BPF_TRAMP_F_ORIG_STACK
> >
> > How can that ever be set?
>
> Oops, my bad! It should be BPF_TRAMP_F_CALL_ORIG here. I think
> it is some kind of copy-paste mistake. I'll send a fix for it.
I sent the following patch twice, but I didn't see it in the
mail list. I suspect there is something wrong with my gmail.
Hi, Alexei. Can you see my patch?
-->patch<--
From 5dbae5dcba3aa7fa10e506e9fd1a28a6802d9b00 Mon Sep 17 00:00:00 2001
From: Menglong Dong <dongml2@chinatelecom.cn>
Date: Fri, 19 Dec 2025 20:33:10 +0800
Subject: [PATCH RESEND bpf] riscv, bpf: fix incorrect usage of BPF_TRAMP_F_ORIG_STACK
The usage of BPF_TRAMP_F_ORIG_STACK in __arch_prepare_bpf_trampoline() is
wrong, and it should be BPF_TRAMP_F_CALL_ORIG, which caused crash as
Andreas reported:
Insufficient stack space to handle exception!
Task stack: [0xff20000000010000..0xff20000000014000]
Overflow stack: [0xff600000ffdad070..0xff600000ffdae070]
CPU: 1 UID: 0 PID: 1 Comm: systemd Not tainted 6.18.0-rc5+ #15 PREEMPT(voluntary)
Hardware name: riscv-virtio qemu/qemu, BIOS 2025.10 10/01/2025
epc : copy_from_kernel_nofault+0xa/0x198
ra : bpf_probe_read_kernel+0x20/0x60
epc : ffffffff802b732a ra : ffffffff801e6070 sp : ff2000000000ffe0
gp : ffffffff82262ed0 tp : 0000000000000000 t0 : ffffffff80022320
t1 : ffffffff801e6056 t2 : 0000000000000000 s0 : ff20000000010040
s1 : 0000000000000008 a0 : ff20000000010050 a1 : ff60000083b3d320
a2 : 0000000000000008 a3 : 0000000000000097 a4 : 0000000000000000
a5 : 0000000000000000 a6 : 0000000000000021 a7 : 0000000000000003
s2 : ff20000000010050 s3 : ff6000008459fc18 s4 : ff60000083b3d340
s5 : ff20000000010060 s6 : 0000000000000000 s7 : ff20000000013aa8
s8 : 0000000000000000 s9 : 0000000000008000 s10: 000000000058dcb0
s11: 000000000058dca7 t3 : 000000006925116d t4 : ff6000008090f026
t5 : 00007fff9b0cbaa8 t6 : 0000000000000016
status: 0000000200000120 badaddr: 0000000000000000 cause: 8000000000000005
Kernel panic - not syncing: Kernel stack overflow
CPU: 1 UID: 0 PID: 1 Comm: systemd Not tainted 6.18.0-rc5+ #15 PREEMPT(voluntary)
Hardware name: riscv-virtio qemu/qemu, BIOS 2025.10 10/01/2025
Call Trace:
[<ffffffff8001a1f8>] dump_backtrace+0x28/0x38
[<ffffffff80002502>] show_stack+0x3a/0x50
[<ffffffff800122be>] dump_stack_lvl+0x56/0x80
[<ffffffff80012300>] dump_stack+0x18/0x22
[<ffffffff80002abe>] vpanic+0xf6/0x328
[<ffffffff80002d2e>] panic+0x3e/0x40
[<ffffffff80019ef0>] handle_bad_stack+0x98/0xa0
[<ffffffff801e6070>] bpf_probe_read_kernel+0x20/0x60
Just fix it.
Fixes: 47c9214dcbea ("bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME")
Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Closes: https://lore.kernel.org/bpf/874ipnkfvt.fsf@igel.home/
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
---
arch/riscv/net/bpf_jit_comp64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
index 5f9457e910e8..09b70bf362d3 100644
--- a/arch/riscv/net/bpf_jit_comp64.c
+++ b/arch/riscv/net/bpf_jit_comp64.c
@@ -1134,7 +1134,7 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im,
store_args(nr_arg_slots, args_off, ctx);
/* skip to actual body of traced function */
- if (flags & BPF_TRAMP_F_ORIG_STACK)
+ if (flags & BPF_TRAMP_F_CALL_ORIG)
orig_call += RV_FENTRY_NINSNS * 4;
if (flags & BPF_TRAMP_F_CALL_ORIG) {
--
2.52.0
--<patch>--
>
> Thanks!
> Menglong Dong
>
> >
> > if (flags & (BPF_TRAMP_F_ORIG_STACK | BPF_TRAMP_F_SHARE_IPMODIFY))
> > return -ENOTSUPP;
> >
> >
>
>
>
>
>
>
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linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH bpf-next v3 3/6] bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME
2025-12-19 13:31 ` Menglong Dong
@ 2025-12-19 13:48 ` Andreas Schwab
2025-12-19 14:04 ` Menglong Dong
0 siblings, 1 reply; 10+ messages in thread
From: Andreas Schwab @ 2025-12-19 13:48 UTC (permalink / raw)
To: Menglong Dong
Cc: ast, Menglong Dong, rostedt, daniel, john.fastabend, andrii,
martin.lau, eddyz87, song, yonghong.song, kpsingh, sdf, haoluo,
jolsa, mhiramat, mark.rutland, mathieu.desnoyers, jiang.biao, bpf,
linux-kernel, linux-trace-kernel, linux-riscv
On Dez 19 2025, Menglong Dong wrote:
> diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
> index 5f9457e910e8..09b70bf362d3 100644
> --- a/arch/riscv/net/bpf_jit_comp64.c
> +++ b/arch/riscv/net/bpf_jit_comp64.c
> @@ -1134,7 +1134,7 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im,
> store_args(nr_arg_slots, args_off, ctx);
>
> /* skip to actual body of traced function */
> - if (flags & BPF_TRAMP_F_ORIG_STACK)
> + if (flags & BPF_TRAMP_F_CALL_ORIG)
> orig_call += RV_FENTRY_NINSNS * 4;
There are now three occurrences of that condition, and only the third
one uses orig_call. How about merging them?
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."
_______________________________________________
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^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH bpf-next v3 3/6] bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME
2025-12-19 13:48 ` Andreas Schwab
@ 2025-12-19 14:04 ` Menglong Dong
2025-12-19 14:50 ` Andreas Schwab
0 siblings, 1 reply; 10+ messages in thread
From: Menglong Dong @ 2025-12-19 14:04 UTC (permalink / raw)
To: Andreas Schwab
Cc: Menglong Dong, ast, rostedt, daniel, john.fastabend, andrii,
martin.lau, eddyz87, song, yonghong.song, kpsingh, sdf, haoluo,
jolsa, mhiramat, mark.rutland, mathieu.desnoyers, jiang.biao, bpf,
linux-kernel, linux-trace-kernel, linux-riscv
On Fri, Dec 19, 2025 at 9:49 PM Andreas Schwab <schwab@linux-m68k.org> wrote:
>
> On Dez 19 2025, Menglong Dong wrote:
>
> > diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
> > index 5f9457e910e8..09b70bf362d3 100644
> > --- a/arch/riscv/net/bpf_jit_comp64.c
> > +++ b/arch/riscv/net/bpf_jit_comp64.c
> > @@ -1134,7 +1134,7 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im,
> > store_args(nr_arg_slots, args_off, ctx);
> >
> > /* skip to actual body of traced function */
> > - if (flags & BPF_TRAMP_F_ORIG_STACK)
> > + if (flags & BPF_TRAMP_F_CALL_ORIG)
> > orig_call += RV_FENTRY_NINSNS * 4;
>
> There are now three occurrences of that condition, and only the third
> one uses orig_call. How about merging them?
Yeah, I think we can merge it to the third one, like this:
diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
index 5f9457e910e8..37888abee70c 100644
--- a/arch/riscv/net/bpf_jit_comp64.c
+++ b/arch/riscv/net/bpf_jit_comp64.c
@@ -1133,10 +1133,6 @@ static int __arch_prepare_bpf_trampoline(struct
bpf_tramp_image *im,
store_args(nr_arg_slots, args_off, ctx);
- /* skip to actual body of traced function */
- if (flags & BPF_TRAMP_F_ORIG_STACK)
- orig_call += RV_FENTRY_NINSNS * 4;
-
if (flags & BPF_TRAMP_F_CALL_ORIG) {
emit_imm(RV_REG_A0, ctx->insns ? (const s64)im :
RV_MAX_COUNT_IMM, ctx);
ret = emit_call((const u64)__bpf_tramp_enter, true, ctx);
@@ -1171,6 +1167,8 @@ static int __arch_prepare_bpf_trampoline(struct
bpf_tramp_image *im,
}
if (flags & BPF_TRAMP_F_CALL_ORIG) {
+ /* skip to actual body of traced function */
+ orig_call += RV_FENTRY_NINSNS * 4;
restore_args(min_t(int, nr_arg_slots,
RV_MAX_REG_ARGS), args_off, ctx);
restore_stack_args(nr_arg_slots - RV_MAX_REG_ARGS,
args_off, stk_arg_off, ctx);
ret = emit_call((const u64)orig_call, true, ctx);
>
> --
> Andreas Schwab, schwab@linux-m68k.org
> GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
> "And now for something completely different."
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH bpf-next v3 3/6] bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME
2025-12-19 14:04 ` Menglong Dong
@ 2025-12-19 14:50 ` Andreas Schwab
2025-12-19 14:54 ` Menglong Dong
0 siblings, 1 reply; 10+ messages in thread
From: Andreas Schwab @ 2025-12-19 14:50 UTC (permalink / raw)
To: Menglong Dong
Cc: Menglong Dong, ast, rostedt, daniel, john.fastabend, andrii,
martin.lau, eddyz87, song, yonghong.song, kpsingh, sdf, haoluo,
jolsa, mhiramat, mark.rutland, mathieu.desnoyers, jiang.biao, bpf,
linux-kernel, linux-trace-kernel, linux-riscv
On Dez 19 2025, Menglong Dong wrote:
> @@ -1171,6 +1167,8 @@ static int __arch_prepare_bpf_trampoline(struct
> bpf_tramp_image *im,
> }
>
> if (flags & BPF_TRAMP_F_CALL_ORIG) {
> + /* skip to actual body of traced function */
> + orig_call += RV_FENTRY_NINSNS * 4;
Before this line, orig_call still contains the same value as func_addr,
with the latter being dead, so there is not much point in using a copy.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH bpf-next v3 3/6] bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME
2025-12-19 14:50 ` Andreas Schwab
@ 2025-12-19 14:54 ` Menglong Dong
0 siblings, 0 replies; 10+ messages in thread
From: Menglong Dong @ 2025-12-19 14:54 UTC (permalink / raw)
To: Andreas Schwab
Cc: Menglong Dong, ast, rostedt, daniel, john.fastabend, andrii,
martin.lau, eddyz87, song, yonghong.song, kpsingh, sdf, haoluo,
jolsa, mhiramat, mark.rutland, mathieu.desnoyers, jiang.biao, bpf,
linux-kernel, linux-trace-kernel, linux-riscv
On Fri, Dec 19, 2025 at 10:50 PM Andreas Schwab <schwab@linux-m68k.org> wrote:
>
> On Dez 19 2025, Menglong Dong wrote:
>
> > @@ -1171,6 +1167,8 @@ static int __arch_prepare_bpf_trampoline(struct
> > bpf_tramp_image *im,
> > }
> >
> > if (flags & BPF_TRAMP_F_CALL_ORIG) {
> > + /* skip to actual body of traced function */
> > + orig_call += RV_FENTRY_NINSNS * 4;
>
> Before this line, orig_call still contains the same value as func_addr,
> with the latter being dead, so there is not much point in using a copy.
Yeah, we can use "func_addr + RV_FENTRY_NINSNS * 4" here directly.
>
> --
> Andreas Schwab, schwab@linux-m68k.org
> GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
> "And now for something completely different."
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
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2025-12-18 14:45 ` [PATCH bpf-next v3 3/6] bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME Andreas Schwab
2025-12-18 15:05 ` Menglong Dong
2025-12-19 2:22 ` Menglong Dong
2025-12-19 11:41 ` Andreas Schwab
2025-12-19 12:27 ` Menglong Dong
2025-12-19 13:31 ` Menglong Dong
2025-12-19 13:48 ` Andreas Schwab
2025-12-19 14:04 ` Menglong Dong
2025-12-19 14:50 ` Andreas Schwab
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