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Fix two tailcall-related issues #9231

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Pull request for series with
subject: Fix two tailcall-related issues
version: 1
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=977599

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Upstream branch: c4b1be9
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=977599
version: 1

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Upstream branch: 26d0e53
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=977599
version: 1

@kernel-patches-daemon-bpf kernel-patches-daemon-bpf bot force-pushed the series/977599=>bpf-next branch from cd40ace to f95d8b5 Compare July 1, 2025 19:40
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Upstream branch: 0df1a55
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=977599
version: 1

@kernel-patches-daemon-bpf kernel-patches-daemon-bpf bot force-pushed the series/977599=>bpf-next branch from f95d8b5 to 9d88f12 Compare July 1, 2025 19:43
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Upstream branch: cce3fee
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=977599
version: 1

@kernel-patches-daemon-bpf kernel-patches-daemon-bpf bot force-pushed the series/977599=>bpf-next branch from 9d88f12 to 6e49da5 Compare July 1, 2025 19:48
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Upstream branch: 1230be8
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=977599
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@kernel-patches-daemon-bpf kernel-patches-daemon-bpf bot force-pushed the series/977599=>bpf-next branch from 6e49da5 to 0e2ea17 Compare July 1, 2025 20:33
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Upstream branch: 212ec92
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=977599
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@kernel-patches-daemon-bpf kernel-patches-daemon-bpf bot force-pushed the series/977599=>bpf-next branch from 0e2ea17 to a12940e Compare July 1, 2025 20:54
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Upstream branch: 621af19
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=977599
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@kernel-patches-daemon-bpf kernel-patches-daemon-bpf bot force-pushed the series/977599=>bpf-next branch from a12940e to bf36eca Compare July 2, 2025 15:04
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Upstream branch: 564606f
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=977599
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@kernel-patches-daemon-bpf kernel-patches-daemon-bpf bot force-pushed the series/977599=>bpf-next branch from bf36eca to 7dd92d3 Compare July 2, 2025 15:46
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Upstream branch: 38d95be
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=977599
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@kernel-patches-daemon-bpf kernel-patches-daemon-bpf bot force-pushed the series/977599=>bpf-next branch from 7dd92d3 to bf06e5c Compare July 2, 2025 18:48
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Upstream branch: ad97cb2
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=979921
version: 2

@kernel-patches-daemon-bpf kernel-patches-daemon-bpf bot force-pushed the series/977599=>bpf-next branch from 3f6e3a7 to 3b3103c Compare July 9, 2025 02:02
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Upstream branch: ea2aecd
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=979921
version: 2

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Upstream branch: e860a98
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=979921
version: 2

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Upstream branch: e860a98
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=979921
version: 2

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Upstream branch: 1f48966
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=979921
version: 2

Haoran Jiang added 2 commits July 16, 2025 18:33
LoongArch: BPF: Optimize the calculation method of jmp_offset in the …
d7d8bab 
…emit_bpf_tail_call function

The extra pass of bpf_int_jit_compile() skips JIT context initialization
which essentially skips offset calculation leaving out_offset = -1,
the jmp_offset in emit_bpf_tail_call is calculated
by #define jmp_offset (out_offset - (cur_offset)) is a negative number,
which does not meet expectations.The final generated assembly as follow.

54:	bgeu        	$a2, $t1, -8	    # 0x0000004c
58:	addi.d      	$a6, $s5, -1
5c:	bltz        	$a6, -16	    # 0x0000004c
60:	alsl.d      	$t2, $a2, $a1, 0x3
64:	ld.d        	$t2, $t2, 264
68:	beq         	$t2, $zero, -28	    # 0x0000004c

Before apply this patch, the follow test case will reveal soft lock issues.

cd tools/testing/selftests/bpf/
./test_progs --allow=tailcalls/tailcall_bpf2bpf_1

dmesg:
watchdog: BUG: soft lockup - CPU#2 stuck for 26s! [test_progs:25056]

Fixes: 5dc6155 ("LoongArch: Add BPF JIT support")
Signed-off-by: Haoran Jiang <[email protected]>
Reviewed-by: Hengqi Chen <[email protected]>
LoongArch: BPF: Fix tailcall hierarchy
a61bd40 
In specific use cases combining tailcalls and BPF-to-BPF calls，
MAX_TAIL_CALL_CNT won't work because of missing tail_call_cnt
back-propagation from callee to caller。This patch fixes this
tailcall issue caused by abusing the tailcall in bpf2bpf feature
on LoongArch like the way of "bpf, x64: Fix tailcall hierarchy".

push tail_call_cnt_ptr and tail_call_cnt into the stack,
tail_call_cnt_ptr is passed between tailcall and bpf2bpf,
uses tail_call_cnt_ptr to increment tail_call_cnt.

Fixes: bb035ef ("LoongArch: BPF: Support mixing bpf2bpf and tailcalls")
Fixes: 5dc6155 ("LoongArch: Add BPF JIT support")
Signed-off-by: Haoran Jiang <[email protected]>
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At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=979921 irrelevant now. Closing PR.

@kernel-patches-daemon-bpf kernel-patches-daemon-bpf bot deleted the series/977599=>bpf-next branch July 17, 2025 01:40
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