* [PATCH v10 0/8] powerpc/bpf: address missing verifier selftest coverage
@ 2026-08-05 6:06 Saket Kumar Bhaskar
2026-08-06 17:34 ` Hari Bathini
2026-08-07 11:42 ` [PATCH v11 " Saket Kumar Bhaskar
0 siblings, 2 replies; 5+ messages in thread
From: Saket Kumar Bhaskar @ 2026-08-05 6:06 UTC (permalink / raw)
To: bpf, linuxppc-dev
Cc: hbathini, maddy, ast, andrii, daniel, shuah, linux-kselftest,
stable, venkat88, yeswanth, skb99
From: Abhishek Dubey <adubey@linux.ibm.com>
The verifier selftest validates JITed instructions by matching expected
disassembly output. The first two patches fix issues in powerpc instruction
disassembly that were causing test flow failures. The fix is common for
64-bit & 32-bit powerpc. Add support for the powerpc-specific "__powerpc64"
architecture tag in the third patch, enabling proper test filtering in
verifier test files. Introduce verifier testcases for tailcalls on powerpc64.
The first patch in series is fix patch, correcting memory alignment with
8-byte boundary for long branch address field. The subsequent patches
enables verifier selftests on powerpc. The fifth patch in the series fixes
incorrect comparator usage for comparing tailcall info with tailcall
threshold. The last two patches fix JIT buffer overflow for large BPF progs
and private stack memory leak (identified by bot during reviews).
Issue Details:
--------------
The Long branch stub in the trampoline implementation[1] provides
flexibility to handles short as well as long branch distance to
actual trampoline. Whereas, the 8 bytes long dummy_tramp_addr field
sitting before long branch stub leads to failure when enabling
verifier based seltest for ppc64.
The verifier selftests require disassembing the final jited image
to get native instructions. Later the disassembled instruction
sequence is matched against sequence of instructions provided in
test-file under __jited() wrapper. The final jited image contains
Out-of-line stub and Long branch stub as part of epilogue jitting
for a bpf program. The 8 bytes space for dummy_tramp is sandwiched
between both above mentioned stubs. These 8 bytes contain memory
address of dummy trampoline during trampoline invocation which don't
correspond to any powerpc instructions. So, disassembly fails
resulting in failure of verifier selftests.
The following code snippet shows the problem with current arrangement
made for dummy_tramp_addr.
/* Out-of-line stub */
mflr r0
[b|bl] tramp
mtlr r0 //only with OOL
b bpf_func + 4
/* Long branch stub */
.long <dummy_tramp_addr> <---Invalid bytes sequence, disassembly fails
mflr r11
bcl 20,31,$+4
mflr r12
ld r12, -8-SZL(r12)
mtctr r12
mtlr r11 //retain ftrace ABI
bctr
Consider test program binary of size 112 bytes:
0: 00000060 10004de8 00002039 f8ff21f9 81ff21f8 7000e1fb 3000e13b
28: 3000e13b 2a006038 f8ff7ff8 00000039 7000e1eb 80002138 7843037d
56: 2000804e a602087c 00000060 a603087c bcffff4b c0341d00 000000c0
84: a602687d 05009f42 a602887d f0ff8ce9 a603897d a603687d 2004804e
Disassembly output of above binary for ppc64le:
pc:0 left:112 00 00 00 60 : nop
pc:4 left:108 10 00 4d e8 : ld 2, 16(13)
pc:8 left:104 00 00 20 39 : li 9, 0
pc:12 left:100 f8 ff 21 f9 : std 9, -8(1)
pc:16 left:96 81 ff 21 f8 : stdu 1, -128(1)
pc:20 left:92 70 00 e1 fb : std 31, 112(1)
pc:24 left:88 30 00 e1 3b : addi 31, 1, 48
pc:28 left:84 30 00 e1 3b : addi 31, 1, 48
pc:32 left:80 2a 00 60 38 : li 3, 42
pc:36 left:76 f8 ff 7f f8 : std 3, -8(31)
pc:40 left:72 00 00 00 39 : li 8, 0
pc:44 left:68 70 00 e1 eb : ld 31, 112(1)
pc:48 left:64 80 00 21 38 : addi 1, 1, 128
pc:52 left:60 78 43 03 7d : mr 3, 8
pc:56 left:56 20 00 80 4e : blr
pc:60 left:52 a6 02 08 7c : mflr 0
pc:64 left:48 00 00 00 60 : nop
pc:68 left:44 a6 03 08 7c : mtlr 0
pc:72 left:40 bc ff ff 4b : b .-68
pc:76 left:36 c0 34 1d 00 :
...
Failure log:
Can't disasm instruction at offset 76: c0 34 1d 00 00 00 00 c0 a6 02 68 7d 05 00 9f 42
--------------------------------------
Observation:
Can't disasm instruction at offset 76 as this address has
".long <dummy_tramp_addr>" (0xc0341d00000000c0)
But valid instructions follow at offset 84 onwards.
Move the long branch address space to the bottom of the long
branch stub. This allows uninterrupted disassembly until the
last 8 bytes. Exclude these last bytes from the overall
program length to prevent failure in assembly generation.
Following is disassembler output for same test program with moved down
dummy_tramp_addr field:
.....
.....
pc:68 left:44 a6 03 08 7c : mtlr 0
pc:72 left:40 bc ff ff 4b : b .-68
pc:76 left:36 a6 02 68 7d : mflr 11
pc:80 left:32 05 00 9f 42 : bcl 20, 31, .+4
pc:84 left:28 a6 02 88 7d : mflr 12
pc:88 left:24 14 00 8c e9 : ld 12, 20(12)
pc:92 left:20 a6 03 89 7d : mtctr 12
pc:96 left:16 a6 03 68 7d : mtlr 11
pc:100 left:12 20 04 80 4e : bctr
pc:104 left:8 c0 34 1d 00 :
Failure log:
Can't disasm instruction at offset 104: c0 34 1d 00 00 00 00 c0
---------------------------------------
Disassembly logic can truncate at 104, ignoring last 8 bytes.
Update the dummy_tramp_addr field offset calculation from the end
of the program to reflect its new location, for bpf_arch_text_poke()
to update the actual trampoline's address in this field.
[1] https://lore.kernel.org/all/20241030070850.1361304-18-hbathini@linux.ibm.com
v9->v10:
Modified expected JIT instruction in selftest for
CONFIG_PPC_KERNEL_PCREL incase of PPC_LI64 instruction.
Fix for stale entries in exception table
Update ARCH_POWERPC64 enum value to 0x40 to resolve rebase
conflict with ARCH_LOONGARCH (0x20).
v8->v9:
Dynamic pass handling until code keeps shrinking
Fix private stack memory leak
v7->v8:
Fixed bot identified issues of alt_exit_addr and BPF_EXIT
Fixed 32-bit ppc function signature mismatch
v6->v7:
Fixed JIT buffer overflow in case of large BPF progs
Addressed remaining bot comments
v5->v6:
Changed alignment NOP emittion dependency on fimage layout
Adjust tail truncate length for 32-bit ppc
Addressed few minor bot comments
v4->v5:
Handled alignment NOP emit logic and corresponding stub offsets
Handled image buffer overflow problem in last pass
Above changes took care of other bot reviews
Included LLVMDisposeMessage() for graceful freeing
Adjusted parameters in bpf_jit_build_fentry_stubs for ppc32
Adjusted expected JIT inst. in tailcall test for
CONFIG_PPC_KERNEL_PCREL config
Added fix patch at last for inaccurate use of cmplwi inst.
v3->v4:
Changed logic for emitting alignment NOP
v2->v3:
Removed fixed NOP from bottom of long branch stub
Rebased on top of bpf-next
v1->v2:
Added fix-patch to correct memory alignment in-place
Moved the optional alignmnet NOP before OOL stub
[v1]: https://lore.kernel.org/bpf/20260225013627.22098-1-adubey@linux.ibm.com
[v2]: https://lore.kernel.org/bpf/20260403004011.44417-1-adubey@linux.ibm.com
[v3]: https://lore.kernel.org/bpf/20260411221413.44304-1-adubey@linux.ibm.com
[v4]: https://lore.kernel.org/bpf/20260517214043.12975-1-adubey@linux.ibm.com
[v5]: https://lore.kernel.org/bpf/20260519233812.18787-1-adubey@linux.ibm.com
[v6]: https://lore.kernel.org/bpf/20260529015855.364704-1-adubey@linux.ibm.com
[v7]: https://lore.kernel.org/bpf/20260611153826.31187-1-adubey@linux.ibm.com
[v8]: https://lore.kernel.org/bpf/20260616164741.32252-1-adubey@linux.ibm.com
[v9]: https://lore.kernel.org/bpf/20260623231411.6216-1-adubey@linux.ibm.com/
Abhishek Dubey (8):
powerpc/bpf: fix alignment of long branch trampoline address
powerpc/bpf: Move out dummy_tramp_addr after Long branch stub
selftest/bpf: Fixing powerpc JIT disassembly failure
selftest/bpf: Enable verifier selftest for powerpc64
powerpc64/bpf: fix compare instruction emitted for tailcall
selftest/bpf: Add tailcall verifier selftest for powerpc64
powerpc/bpf: fix buffer overflow in JIT for large BPF programs
powerpc64/bpf: fix percpu private stack leak on JIT failure
arch/powerpc/net/bpf_jit.h | 20 +++-
arch/powerpc/net/bpf_jit_comp.c | 102 +++++++++++++-----
arch/powerpc/net/bpf_jit_comp32.c | 7 +-
arch/powerpc/net/bpf_jit_comp64.c | 15 +--
.../selftests/bpf/jit_disasm_helpers.c | 25 ++++-
tools/testing/selftests/bpf/progs/bpf_misc.h | 1 +
.../bpf/progs/verifier_tailcall_jit.c | 74 +++++++++++++
tools/testing/selftests/bpf/test_loader.c | 5 +
8 files changed, 209 insertions(+), 40 deletions(-)
--
2.54.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v10 0/8] powerpc/bpf: address missing verifier selftest coverage
2026-08-05 6:06 [PATCH v10 0/8] powerpc/bpf: address missing verifier selftest coverage Saket Kumar Bhaskar
@ 2026-08-06 17:34 ` Hari Bathini
2026-08-07 3:21 ` Madhavan Srinivasan
2026-08-07 11:47 ` Saket Kumar Bhaskar
2026-08-07 11:42 ` [PATCH v11 " Saket Kumar Bhaskar
1 sibling, 2 replies; 5+ messages in thread
From: Hari Bathini @ 2026-08-06 17:34 UTC (permalink / raw)
To: Saket Kumar Bhaskar, bpf, linuxppc-dev
Cc: maddy, ast, andrii, daniel, shuah, linux-kselftest, stable,
venkat88, yeswanth
On 05/08/26 11:36 am, Saket Kumar Bhaskar wrote:
> From: Abhishek Dubey <adubey@linux.ibm.com>
>
> The verifier selftest validates JITed instructions by matching expected
> disassembly output. The first two patches fix issues in powerpc instruction
> disassembly that were causing test flow failures. The fix is common for
> 64-bit & 32-bit powerpc. Add support for the powerpc-specific "__powerpc64"
> architecture tag in the third patch, enabling proper test filtering in
> verifier test files. Introduce verifier testcases for tailcalls on powerpc64.
>
> The first patch in series is fix patch, correcting memory alignment with
> 8-byte boundary for long branch address field. The subsequent patches
> enables verifier selftests on powerpc. The fifth patch in the series fixes
> incorrect comparator usage for comparing tailcall info with tailcall
> threshold. The last two patches fix JIT buffer overflow for large BPF progs
> and private stack memory leak (identified by bot during reviews).
>
> Issue Details:
> --------------
>
> The Long branch stub in the trampoline implementation[1] provides
> flexibility to handles short as well as long branch distance to
> actual trampoline. Whereas, the 8 bytes long dummy_tramp_addr field
> sitting before long branch stub leads to failure when enabling
> verifier based seltest for ppc64.
>
> The verifier selftests require disassembing the final jited image
> to get native instructions. Later the disassembled instruction
> sequence is matched against sequence of instructions provided in
> test-file under __jited() wrapper. The final jited image contains
> Out-of-line stub and Long branch stub as part of epilogue jitting
> for a bpf program. The 8 bytes space for dummy_tramp is sandwiched
> between both above mentioned stubs. These 8 bytes contain memory
> address of dummy trampoline during trampoline invocation which don't
> correspond to any powerpc instructions. So, disassembly fails
> resulting in failure of verifier selftests.
>
> The following code snippet shows the problem with current arrangement
> made for dummy_tramp_addr.
>
> /* Out-of-line stub */
> mflr r0
> [b|bl] tramp
> mtlr r0 //only with OOL
> b bpf_func + 4
> /* Long branch stub */
> .long <dummy_tramp_addr> <---Invalid bytes sequence, disassembly fails
> mflr r11
> bcl 20,31,$+4
> mflr r12
> ld r12, -8-SZL(r12)
> mtctr r12
> mtlr r11 //retain ftrace ABI
> bctr
>
> Consider test program binary of size 112 bytes:
> 0: 00000060 10004de8 00002039 f8ff21f9 81ff21f8 7000e1fb 3000e13b
> 28: 3000e13b 2a006038 f8ff7ff8 00000039 7000e1eb 80002138 7843037d
> 56: 2000804e a602087c 00000060 a603087c bcffff4b c0341d00 000000c0
> 84: a602687d 05009f42 a602887d f0ff8ce9 a603897d a603687d 2004804e
>
> Disassembly output of above binary for ppc64le:
> pc:0 left:112 00 00 00 60 : nop
> pc:4 left:108 10 00 4d e8 : ld 2, 16(13)
> pc:8 left:104 00 00 20 39 : li 9, 0
> pc:12 left:100 f8 ff 21 f9 : std 9, -8(1)
> pc:16 left:96 81 ff 21 f8 : stdu 1, -128(1)
> pc:20 left:92 70 00 e1 fb : std 31, 112(1)
> pc:24 left:88 30 00 e1 3b : addi 31, 1, 48
> pc:28 left:84 30 00 e1 3b : addi 31, 1, 48
> pc:32 left:80 2a 00 60 38 : li 3, 42
> pc:36 left:76 f8 ff 7f f8 : std 3, -8(31)
> pc:40 left:72 00 00 00 39 : li 8, 0
> pc:44 left:68 70 00 e1 eb : ld 31, 112(1)
> pc:48 left:64 80 00 21 38 : addi 1, 1, 128
> pc:52 left:60 78 43 03 7d : mr 3, 8
> pc:56 left:56 20 00 80 4e : blr
> pc:60 left:52 a6 02 08 7c : mflr 0
> pc:64 left:48 00 00 00 60 : nop
> pc:68 left:44 a6 03 08 7c : mtlr 0
> pc:72 left:40 bc ff ff 4b : b .-68
> pc:76 left:36 c0 34 1d 00 :
> ...
>
> Failure log:
> Can't disasm instruction at offset 76: c0 34 1d 00 00 00 00 c0 a6 02 68 7d 05 00 9f 42
> --------------------------------------
>
> Observation:
> Can't disasm instruction at offset 76 as this address has
> ".long <dummy_tramp_addr>" (0xc0341d00000000c0)
> But valid instructions follow at offset 84 onwards.
>
> Move the long branch address space to the bottom of the long
> branch stub. This allows uninterrupted disassembly until the
> last 8 bytes. Exclude these last bytes from the overall
> program length to prevent failure in assembly generation.
>
> Following is disassembler output for same test program with moved down
> dummy_tramp_addr field:
> .....
> .....
> pc:68 left:44 a6 03 08 7c : mtlr 0
> pc:72 left:40 bc ff ff 4b : b .-68
> pc:76 left:36 a6 02 68 7d : mflr 11
> pc:80 left:32 05 00 9f 42 : bcl 20, 31, .+4
> pc:84 left:28 a6 02 88 7d : mflr 12
> pc:88 left:24 14 00 8c e9 : ld 12, 20(12)
> pc:92 left:20 a6 03 89 7d : mtctr 12
> pc:96 left:16 a6 03 68 7d : mtlr 11
> pc:100 left:12 20 04 80 4e : bctr
> pc:104 left:8 c0 34 1d 00 :
>
> Failure log:
> Can't disasm instruction at offset 104: c0 34 1d 00 00 00 00 c0
> ---------------------------------------
> Disassembly logic can truncate at 104, ignoring last 8 bytes.
>
> Update the dummy_tramp_addr field offset calculation from the end
> of the program to reflect its new location, for bpf_arch_text_poke()
> to update the actual trampoline's address in this field.
>
> [1] https://lore.kernel.org/all/20241030070850.1361304-18-hbathini@linux.ibm.com
>
> v9->v10:
> Modified expected JIT instruction in selftest for
> CONFIG_PPC_KERNEL_PCREL incase of PPC_LI64 instruction.
> Fix for stale entries in exception table
> Update ARCH_POWERPC64 enum value to 0x40 to resolve rebase
> conflict with ARCH_LOONGARCH (0x20).
>
> v8->v9:
> Dynamic pass handling until code keeps shrinking
> Fix private stack memory leak
>
> v7->v8:
> Fixed bot identified issues of alt_exit_addr and BPF_EXIT
> Fixed 32-bit ppc function signature mismatch
>
> v6->v7:
> Fixed JIT buffer overflow in case of large BPF progs
> Addressed remaining bot comments
>
> v5->v6:
> Changed alignment NOP emittion dependency on fimage layout
> Adjust tail truncate length for 32-bit ppc
> Addressed few minor bot comments
>
> v4->v5:
> Handled alignment NOP emit logic and corresponding stub offsets
> Handled image buffer overflow problem in last pass
> Above changes took care of other bot reviews
> Included LLVMDisposeMessage() for graceful freeing
> Adjusted parameters in bpf_jit_build_fentry_stubs for ppc32
> Adjusted expected JIT inst. in tailcall test for
> CONFIG_PPC_KERNEL_PCREL config
> Added fix patch at last for inaccurate use of cmplwi inst.
>
> v3->v4:
> Changed logic for emitting alignment NOP
>
> v2->v3:
> Removed fixed NOP from bottom of long branch stub
> Rebased on top of bpf-next
>
> v1->v2:
> Added fix-patch to correct memory alignment in-place
> Moved the optional alignmnet NOP before OOL stub
>
> [v1]: https://lore.kernel.org/bpf/20260225013627.22098-1-adubey@linux.ibm.com
> [v2]: https://lore.kernel.org/bpf/20260403004011.44417-1-adubey@linux.ibm.com
> [v3]: https://lore.kernel.org/bpf/20260411221413.44304-1-adubey@linux.ibm.com
> [v4]: https://lore.kernel.org/bpf/20260517214043.12975-1-adubey@linux.ibm.com
> [v5]: https://lore.kernel.org/bpf/20260519233812.18787-1-adubey@linux.ibm.com
> [v6]: https://lore.kernel.org/bpf/20260529015855.364704-1-adubey@linux.ibm.com
> [v7]: https://lore.kernel.org/bpf/20260611153826.31187-1-adubey@linux.ibm.com
> [v8]: https://lore.kernel.org/bpf/20260616164741.32252-1-adubey@linux.ibm.com
> [v9]: https://lore.kernel.org/bpf/20260623231411.6216-1-adubey@linux.ibm.com/
>
> Abhishek Dubey (8):
> powerpc/bpf: fix alignment of long branch trampoline addres to t
> powerpc/bpf: Move out dummy_tramp_addr after Long branch stub
> selftest/bpf: Fixing powerpc JIT disassembly failure
> selftest/bpf: Enable verifier selftest for powerpc64
> powerpc64/bpf: fix compare instruction emitted for tailcall
> selftest/bpf: Add tailcall verifier selftest for powerpc64
> powerpc/bpf: fix buffer overflow in JIT for large BPF programs
> powerpc64/bpf: fix percpu private stack leak on JIT failure
>
> arch/powerpc/net/bpf_jit.h | 20 +++-
> arch/powerpc/net/bpf_jit_comp.c | 102 +++++++++++++-----
> arch/powerpc/net/bpf_jit_comp32.c | 7 +-
> arch/powerpc/net/bpf_jit_comp64.c | 15 +--
> .../selftests/bpf/jit_disasm_helpers.c | 25 ++++-
> tools/testing/selftests/bpf/progs/bpf_misc.h | 1 +
> .../bpf/progs/verifier_tailcall_jit.c | 74 +++++++++++++
> tools/testing/selftests/bpf/test_loader.c | 5 +
> 8 files changed, 209 insertions(+), 40 deletions(-)
>
Alexei, Maddy,
Given this has changes in common code too, should this go via bpf tree?
If yes, @Saket can you post the next revision with bpf tag to make
it explicit...
- Hari
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v10 0/8] powerpc/bpf: address missing verifier selftest coverage
2026-08-06 17:34 ` Hari Bathini
@ 2026-08-07 3:21 ` Madhavan Srinivasan
2026-08-07 11:47 ` Saket Kumar Bhaskar
1 sibling, 0 replies; 5+ messages in thread
From: Madhavan Srinivasan @ 2026-08-07 3:21 UTC (permalink / raw)
To: Hari Bathini, Saket Kumar Bhaskar, bpf, linuxppc-dev
Cc: ast, andrii, daniel, shuah, linux-kselftest, stable, venkat88,
yeswanth
On 8/6/26 11:04 PM, Hari Bathini wrote:
>
>
> On 05/08/26 11:36 am, Saket Kumar Bhaskar wrote:
>> From: Abhishek Dubey <adubey@linux.ibm.com>
>>
>> The verifier selftest validates JITed instructions by matching expected
>> disassembly output. The first two patches fix issues in powerpc
>> instruction
>> disassembly that were causing test flow failures. The fix is common for
>> 64-bit & 32-bit powerpc. Add support for the powerpc-specific
>> "__powerpc64"
>> architecture tag in the third patch, enabling proper test filtering in
>> verifier test files. Introduce verifier testcases for tailcalls on
>> powerpc64.
>>
>> The first patch in series is fix patch, correcting memory alignment with
>> 8-byte boundary for long branch address field. The subsequent patches
>> enables verifier selftests on powerpc. The fifth patch in the series
>> fixes
>> incorrect comparator usage for comparing tailcall info with tailcall
>> threshold. The last two patches fix JIT buffer overflow for large BPF
>> progs
>> and private stack memory leak (identified by bot during reviews).
>>
>> Issue Details:
>> --------------
>>
>> The Long branch stub in the trampoline implementation[1] provides
>> flexibility to handles short as well as long branch distance to
>> actual trampoline. Whereas, the 8 bytes long dummy_tramp_addr field
>> sitting before long branch stub leads to failure when enabling
>> verifier based seltest for ppc64.
>> The verifier selftests require disassembing the final jited
>> image
>> to get native instructions. Later the disassembled instruction
>> sequence is matched against sequence of instructions provided in
>> test-file under __jited() wrapper. The final jited image contains
>> Out-of-line stub and Long branch stub as part of epilogue jitting
>> for a bpf program. The 8 bytes space for dummy_tramp is sandwiched
>> between both above mentioned stubs. These 8 bytes contain memory
>> address of dummy trampoline during trampoline invocation which
>> don't
>> correspond to any powerpc instructions. So, disassembly fails
>> resulting in failure of verifier selftests.
>> The following code snippet shows the problem with current
>> arrangement
>> made for dummy_tramp_addr.
>> /* Out-of-line stub */
>> mflr r0
>> [b|bl] tramp
>> mtlr r0 //only with OOL
>> b bpf_func + 4
>> /* Long branch stub */
>> .long <dummy_tramp_addr> <---Invalid bytes sequence,
>> disassembly fails
>> mflr r11
>> bcl 20,31,$+4
>> mflr r12
>> ld r12, -8-SZL(r12)
>> mtctr r12
>> mtlr r11 //retain ftrace ABI
>> bctr
>>
>> Consider test program binary of size 112 bytes:
>> 0: 00000060 10004de8 00002039 f8ff21f9 81ff21f8 7000e1fb 3000e13b
>> 28: 3000e13b 2a006038 f8ff7ff8 00000039 7000e1eb 80002138 7843037d
>> 56: 2000804e a602087c 00000060 a603087c bcffff4b c0341d00 000000c0
>> 84: a602687d 05009f42 a602887d f0ff8ce9 a603897d a603687d 2004804e
>>
>> Disassembly output of above binary for ppc64le:
>> pc:0 left:112 00 00 00 60 : nop
>> pc:4 left:108 10 00 4d e8 : ld 2, 16(13)
>> pc:8 left:104 00 00 20 39 : li 9, 0
>> pc:12 left:100 f8 ff 21 f9 : std 9, -8(1)
>> pc:16 left:96 81 ff 21 f8 : stdu 1, -128(1)
>> pc:20 left:92 70 00 e1 fb : std 31, 112(1)
>> pc:24 left:88 30 00 e1 3b : addi 31, 1, 48
>> pc:28 left:84 30 00 e1 3b : addi 31, 1, 48
>> pc:32 left:80 2a 00 60 38 : li 3, 42
>> pc:36 left:76 f8 ff 7f f8 : std 3, -8(31)
>> pc:40 left:72 00 00 00 39 : li 8, 0
>> pc:44 left:68 70 00 e1 eb : ld 31, 112(1)
>> pc:48 left:64 80 00 21 38 : addi 1, 1, 128
>> pc:52 left:60 78 43 03 7d : mr 3, 8
>> pc:56 left:56 20 00 80 4e : blr
>> pc:60 left:52 a6 02 08 7c : mflr 0
>> pc:64 left:48 00 00 00 60 : nop
>> pc:68 left:44 a6 03 08 7c : mtlr 0
>> pc:72 left:40 bc ff ff 4b : b .-68
>> pc:76 left:36 c0 34 1d 00 :
>> ...
>>
>> Failure log:
>> Can't disasm instruction at offset 76: c0 34 1d 00 00 00 00 c0
>> a6 02 68 7d 05 00 9f 42
>> --------------------------------------
>>
>> Observation:
>> Can't disasm instruction at offset 76 as this address has
>> ".long <dummy_tramp_addr>" (0xc0341d00000000c0)
>> But valid instructions follow at offset 84 onwards.
>>
>> Move the long branch address space to the bottom of the long
>> branch stub. This allows uninterrupted disassembly until the
>> last 8 bytes. Exclude these last bytes from the overall
>> program length to prevent failure in assembly generation.
>>
>> Following is disassembler output for same test program with
>> moved down
>> dummy_tramp_addr field:
>> .....
>> .....
>> pc:68 left:44 a6 03 08 7c : mtlr 0
>> pc:72 left:40 bc ff ff 4b : b .-68
>> pc:76 left:36 a6 02 68 7d : mflr 11
>> pc:80 left:32 05 00 9f 42 : bcl 20, 31, .+4
>> pc:84 left:28 a6 02 88 7d : mflr 12
>> pc:88 left:24 14 00 8c e9 : ld 12, 20(12)
>> pc:92 left:20 a6 03 89 7d : mtctr 12
>> pc:96 left:16 a6 03 68 7d : mtlr 11
>> pc:100 left:12 20 04 80 4e : bctr
>> pc:104 left:8 c0 34 1d 00 :
>>
>> Failure log:
>> Can't disasm instruction at offset 104: c0 34 1d 00 00 00 00 c0
>> ---------------------------------------
>> Disassembly logic can truncate at 104, ignoring last 8 bytes.
>>
>> Update the dummy_tramp_addr field offset calculation from the end
>> of the program to reflect its new location, for
>> bpf_arch_text_poke()
>> to update the actual trampoline's address in this field.
>>
>> [1]
>> https://lore.kernel.org/all/20241030070850.1361304-18-hbathini@linux.ibm.com
>>
>> v9->v10:
>> Modified expected JIT instruction in selftest for
>> CONFIG_PPC_KERNEL_PCREL incase of PPC_LI64 instruction.
>> Fix for stale entries in exception table
>> Update ARCH_POWERPC64 enum value to 0x40 to resolve rebase
>> conflict with ARCH_LOONGARCH (0x20).
>>
>> v8->v9:
>> Dynamic pass handling until code keeps shrinking
>> Fix private stack memory leak
>>
>> v7->v8:
>> Fixed bot identified issues of alt_exit_addr and BPF_EXIT
>> Fixed 32-bit ppc function signature mismatch
>>
>> v6->v7:
>> Fixed JIT buffer overflow in case of large BPF progs
>> Addressed remaining bot comments
>>
>> v5->v6:
>> Changed alignment NOP emittion dependency on fimage layout
>> Adjust tail truncate length for 32-bit ppc
>> Addressed few minor bot comments
>>
>> v4->v5:
>> Handled alignment NOP emit logic and corresponding stub offsets
>> Handled image buffer overflow problem in last pass
>> Above changes took care of other bot reviews
>> Included LLVMDisposeMessage() for graceful freeing
>> Adjusted parameters in bpf_jit_build_fentry_stubs for ppc32
>> Adjusted expected JIT inst. in tailcall test for
>> CONFIG_PPC_KERNEL_PCREL config
>> Added fix patch at last for inaccurate use of cmplwi inst.
>>
>> v3->v4:
>> Changed logic for emitting alignment NOP
>>
>> v2->v3:
>> Removed fixed NOP from bottom of long branch stub
>> Rebased on top of bpf-next
>>
>> v1->v2:
>> Added fix-patch to correct memory alignment in-place
>> Moved the optional alignmnet NOP before OOL stub
>>
>> [v1]:
>> https://lore.kernel.org/bpf/20260225013627.22098-1-adubey@linux.ibm.com
>> [v2]:
>> https://lore.kernel.org/bpf/20260403004011.44417-1-adubey@linux.ibm.com
>> [v3]:
>> https://lore.kernel.org/bpf/20260411221413.44304-1-adubey@linux.ibm.com
>> [v4]:
>> https://lore.kernel.org/bpf/20260517214043.12975-1-adubey@linux.ibm.com
>> [v5]:
>> https://lore.kernel.org/bpf/20260519233812.18787-1-adubey@linux.ibm.com
>> [v6]:
>> https://lore.kernel.org/bpf/20260529015855.364704-1-adubey@linux.ibm.com
>> [v7]:
>> https://lore.kernel.org/bpf/20260611153826.31187-1-adubey@linux.ibm.com
>> [v8]:
>> https://lore.kernel.org/bpf/20260616164741.32252-1-adubey@linux.ibm.com
>> [v9]:
>> https://lore.kernel.org/bpf/20260623231411.6216-1-adubey@linux.ibm.com/
>>
>> Abhishek Dubey (8):
>> powerpc/bpf: fix alignment of long branch trampoline addres to t
>> powerpc/bpf: Move out dummy_tramp_addr after Long branch stub
>> selftest/bpf: Fixing powerpc JIT disassembly failure
>> selftest/bpf: Enable verifier selftest for powerpc64
>> powerpc64/bpf: fix compare instruction emitted for tailcall
>> selftest/bpf: Add tailcall verifier selftest for powerpc64
>> powerpc/bpf: fix buffer overflow in JIT for large BPF programs
>> powerpc64/bpf: fix percpu private stack leak on JIT failure
>>
>> arch/powerpc/net/bpf_jit.h | 20 +++-
>> arch/powerpc/net/bpf_jit_comp.c | 102 +++++++++++++-----
>> arch/powerpc/net/bpf_jit_comp32.c | 7 +-
>> arch/powerpc/net/bpf_jit_comp64.c | 15 +--
>> .../selftests/bpf/jit_disasm_helpers.c | 25 ++++-
>> tools/testing/selftests/bpf/progs/bpf_misc.h | 1 +
>> .../bpf/progs/verifier_tailcall_jit.c | 74 +++++++++++++
>> tools/testing/selftests/bpf/test_loader.c | 5 +
>> 8 files changed, 209 insertions(+), 40 deletions(-)
>>
>
> Alexei, Maddy,
>
> Given this has changes in common code too, should this go via bpf tree?
> If yes, @Saket can you post the next revision with bpf tag to make
> it explicit...
If I get an ack from Alexei, I can take this via ppc tree.
Maddy
>
> - Hari
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v11 0/8] powerpc/bpf: address missing verifier selftest coverage
2026-08-05 6:06 [PATCH v10 0/8] powerpc/bpf: address missing verifier selftest coverage Saket Kumar Bhaskar
2026-08-06 17:34 ` Hari Bathini
@ 2026-08-07 11:42 ` Saket Kumar Bhaskar
1 sibling, 0 replies; 5+ messages in thread
From: Saket Kumar Bhaskar @ 2026-08-07 11:42 UTC (permalink / raw)
To: bpf, linuxppc-dev
Cc: hbathini, maddy, ast, andrii, daniel, shuah, linux-kselftest,
stable, venkat88, yeswanth, skb99
From: Abhishek Dubey <adubey@linux.ibm.com>
The verifier selftest validates JITed instructions by matching expected
disassembly output. The first two patches fix issues in powerpc instruction
disassembly that were causing test flow failures. The fix is common for
64-bit & 32-bit powerpc. Add support for the powerpc-specific "__powerpc64"
architecture tag in the third patch, enabling proper test filtering in
verifier test files. Introduce verifier testcases for tailcalls on
powerpc64.
The first patch in series is fix patch, correcting memory alignment with
8-byte boundary for long branch address field. The subsequent patches
enables verifier selftests on powerpc. The fifth patch in the series fixes
incorrect comparator usage for comparing tailcall info with tailcall
threshold. The last two patches fix JIT buffer overflow for large BPF progs
and private stack memory leak (identified by bot during reviews).
Issue Details:
--------------
The Long branch stub in the trampoline implementation[1] provides
flexibility to handles short as well as long branch distance to
actual trampoline. Whereas, the 8 bytes long dummy_tramp_addr field
sitting before long branch stub leads to failure when enabling
verifier based seltest for ppc64.
The verifier selftests require disassembing the final jited image
to get native instructions. Later the disassembled instruction
sequence is matched against sequence of instructions provided in
test-file under __jited() wrapper. The final jited image contains
Out-of-line stub and Long branch stub as part of epilogue jitting
for a bpf program. The 8 bytes space for dummy_tramp is sandwiched
between both above mentioned stubs. These 8 bytes contain memory
address of dummy trampoline during trampoline invocation which don't
correspond to any powerpc instructions. So, disassembly fails
resulting in failure of verifier selftests.
The following code snippet shows the problem with current arrangement
made for dummy_tramp_addr.
/* Out-of-line stub */
mflr r0
[b|bl] tramp
mtlr r0 //only with OOL
b bpf_func + 4
/* Long branch stub */
.long <dummy_tramp_addr> <---Invalid bytes sequence, disassembly fails
mflr r11
bcl 20,31,$+4
mflr r12
ld r12, -8-SZL(r12)
mtctr r12
mtlr r11 //retain ftrace ABI
bctr
Consider test program binary of size 112 bytes:
0: 00000060 10004de8 00002039 f8ff21f9 81ff21f8 7000e1fb 3000e13b
28: 3000e13b 2a006038 f8ff7ff8 00000039 7000e1eb 80002138 7843037d
56: 2000804e a602087c 00000060 a603087c bcffff4b c0341d00 000000c0
84: a602687d 05009f42 a602887d f0ff8ce9 a603897d a603687d 2004804e
Disassembly output of above binary for ppc64le:
pc:0 left:112 00 00 00 60 : nop
pc:4 left:108 10 00 4d e8 : ld 2, 16(13)
pc:8 left:104 00 00 20 39 : li 9, 0
pc:12 left:100 f8 ff 21 f9 : std 9, -8(1)
pc:16 left:96 81 ff 21 f8 : stdu 1, -128(1)
pc:20 left:92 70 00 e1 fb : std 31, 112(1)
pc:24 left:88 30 00 e1 3b : addi 31, 1, 48
pc:28 left:84 30 00 e1 3b : addi 31, 1, 48
pc:32 left:80 2a 00 60 38 : li 3, 42
pc:36 left:76 f8 ff 7f f8 : std 3, -8(31)
pc:40 left:72 00 00 00 39 : li 8, 0
pc:44 left:68 70 00 e1 eb : ld 31, 112(1)
pc:48 left:64 80 00 21 38 : addi 1, 1, 128
pc:52 left:60 78 43 03 7d : mr 3, 8
pc:56 left:56 20 00 80 4e : blr
pc:60 left:52 a6 02 08 7c : mflr 0
pc:64 left:48 00 00 00 60 : nop
pc:68 left:44 a6 03 08 7c : mtlr 0
pc:72 left:40 bc ff ff 4b : b .-68
pc:76 left:36 c0 34 1d 00 :
...
Failure log:
Can't disasm instruction at offset 76: c0 34 1d 00 00 00 00 c0 a6 02 68 7d 05 00 9f 42
--------------------------------------
Observation:
Can't disasm instruction at offset 76 as this address has
".long <dummy_tramp_addr>" (0xc0341d00000000c0)
But valid instructions follow at offset 84 onwards.
Move the long branch address space to the bottom of the long
branch stub. This allows uninterrupted disassembly until the
last 8 bytes. Exclude these last bytes from the overall
program length to prevent failure in assembly generation.
Following is disassembler output for same test program with moved down
dummy_tramp_addr field:
.....
.....
pc:68 left:44 a6 03 08 7c : mtlr 0
pc:72 left:40 bc ff ff 4b : b .-68
pc:76 left:36 a6 02 68 7d : mflr 11
pc:80 left:32 05 00 9f 42 : bcl 20, 31, .+4
pc:84 left:28 a6 02 88 7d : mflr 12
pc:88 left:24 14 00 8c e9 : ld 12, 20(12)
pc:92 left:20 a6 03 89 7d : mtctr 12
pc:96 left:16 a6 03 68 7d : mtlr 11
pc:100 left:12 20 04 80 4e : bctr
pc:104 left:8 c0 34 1d 00 :
Failure log:
Can't disasm instruction at offset 104: c0 34 1d 00 00 00 00 c0
---------------------------------------
Disassembly logic can truncate at 104, ignoring last 8 bytes.
Update the dummy_tramp_addr field offset calculation from the end
of the program to reflect its new location, for bpf_arch_text_poke()
to update the actual trampoline's address in this field.
[1] https://lore.kernel.org/all/20241030070850.1361304-18-hbathini@linux.ibm.com
v10->v11:
Moved function prototype change from patch 2 to patch 1
Fixed commit message for patch 1 and patch 4
Fixed extable entry generation condition
Added reviewed and acked tags by Hari
v9->v10:
Modified expected JIT instruction in selftest for
CONFIG_PPC_KERNEL_PCREL incase of PPC_LI64 instruction.
Fix for stale entries in exception table
Update ARCH_POWERPC64 enum value to 0x40 to resolve rebase
conflict with ARCH_LOONGARCH (0x20).
v8->v9:
Dynamic pass handling until code keeps shrinking
Fix private stack memory leak
v7->v8:
Fixed bot identified issues of alt_exit_addr and BPF_EXIT
Fixed 32-bit ppc function signature mismatch
v6->v7:
Fixed JIT buffer overflow in case of large BPF progs
Addressed remaining bot comments
v5->v6:
Changed alignment NOP emittion dependency on fimage layout
Adjust tail truncate length for 32-bit ppc
Addressed few minor bot comments
v4->v5:
Handled alignment NOP emit logic and corresponding stub offsets
Handled image buffer overflow problem in last pass
Above changes took care of other bot reviews
Included LLVMDisposeMessage() for graceful freeing
Adjusted parameters in bpf_jit_build_fentry_stubs for ppc32
Adjusted expected JIT inst. in tailcall test for
CONFIG_PPC_KERNEL_PCREL config
Added fix patch at last for inaccurate use of cmplwi inst.
v3->v4:
Changed logic for emitting alignment NOP
v2->v3:
Removed fixed NOP from bottom of long branch stub
Rebased on top of bpf-next
v1->v2:
Added fix-patch to correct memory alignment in-place
Moved the optional alignmnet NOP before OOL stub
[v1]: https://lore.kernel.org/bpf/20260225013627.22098-1-adubey@linux.ibm.com
[v2]: https://lore.kernel.org/bpf/20260403004011.44417-1-adubey@linux.ibm.com
[v3]: https://lore.kernel.org/bpf/20260411221413.44304-1-adubey@linux.ibm.com
[v4]: https://lore.kernel.org/bpf/20260517214043.12975-1-adubey@linux.ibm.com
[v5]: https://lore.kernel.org/bpf/20260519233812.18787-1-adubey@linux.ibm.com
[v6]: https://lore.kernel.org/bpf/20260529015855.364704-1-adubey@linux.ibm.com
[v7]: https://lore.kernel.org/bpf/20260611153826.31187-1-adubey@linux.ibm.com
[v8]: https://lore.kernel.org/bpf/20260616164741.32252-1-adubey@linux.ibm.com
[v9]: https://lore.kernel.org/bpf/20260623231411.6216-1-adubey@linux.ibm.com/
[v10]: https://lore.kernel.org/all/26e8e6fa5d0279ec92281d5324678f00294e2cb7.1785906979.git.skb99@linux.ibm.com/
Abhishek Dubey (8):
powerpc/bpf: fix alignment of long branch trampoline address
powerpc/bpf: Move out dummy_tramp_addr after Long branch stub
selftest/bpf: Fixing powerpc JIT disassembly failure
selftest/bpf: Enable verifier selftest for powerpc64
powerpc64/bpf: fix compare instruction emitted for tailcall
selftest/bpf: Add tailcall verifier selftest for powerpc64
powerpc/bpf: fix buffer overflow in JIT for large BPF programs
powerpc64/bpf: fix percpu private stack leak on JIT failure
arch/powerpc/net/bpf_jit.h | 20 +++-
arch/powerpc/net/bpf_jit_comp.c | 102 +++++++++++++-----
arch/powerpc/net/bpf_jit_comp32.c | 7 +-
arch/powerpc/net/bpf_jit_comp64.c | 15 +--
.../selftests/bpf/jit_disasm_helpers.c | 25 ++++-
tools/testing/selftests/bpf/progs/bpf_misc.h | 1 +
.../bpf/progs/verifier_tailcall_jit.c | 74 +++++++++++++
tools/testing/selftests/bpf/test_loader.c | 5 +
8 files changed, 209 insertions(+), 40 deletions(-)
--
2.54.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v10 0/8] powerpc/bpf: address missing verifier selftest coverage
2026-08-06 17:34 ` Hari Bathini
2026-08-07 3:21 ` Madhavan Srinivasan
@ 2026-08-07 11:47 ` Saket Kumar Bhaskar
1 sibling, 0 replies; 5+ messages in thread
From: Saket Kumar Bhaskar @ 2026-08-07 11:47 UTC (permalink / raw)
To: Hari Bathini
Cc: bpf, linuxppc-dev, maddy, ast, andrii, daniel, shuah,
linux-kselftest, stable, venkat88, yeswanth
On Thu, Aug 06, 2026 at 11:04:04PM +0530, Hari Bathini wrote:
>
>
> On 05/08/26 11:36 am, Saket Kumar Bhaskar wrote:
> > From: Abhishek Dubey <adubey@linux.ibm.com>
> >
> > The verifier selftest validates JITed instructions by matching expected
> > disassembly output. The first two patches fix issues in powerpc instruction
> > disassembly that were causing test flow failures. The fix is common for
> > 64-bit & 32-bit powerpc. Add support for the powerpc-specific "__powerpc64"
> > architecture tag in the third patch, enabling proper test filtering in
> > verifier test files. Introduce verifier testcases for tailcalls on powerpc64.
> >
> > The first patch in series is fix patch, correcting memory alignment with
> > 8-byte boundary for long branch address field. The subsequent patches
> > enables verifier selftests on powerpc. The fifth patch in the series fixes
> > incorrect comparator usage for comparing tailcall info with tailcall
> > threshold. The last two patches fix JIT buffer overflow for large BPF progs
> > and private stack memory leak (identified by bot during reviews).
> >
> > Issue Details:
> > --------------
> >
> > The Long branch stub in the trampoline implementation[1] provides
> > flexibility to handles short as well as long branch distance to
> > actual trampoline. Whereas, the 8 bytes long dummy_tramp_addr field
> > sitting before long branch stub leads to failure when enabling
> > verifier based seltest for ppc64.
> > The verifier selftests require disassembing the final jited image
> > to get native instructions. Later the disassembled instruction
> > sequence is matched against sequence of instructions provided in
> > test-file under __jited() wrapper. The final jited image contains
> > Out-of-line stub and Long branch stub as part of epilogue jitting
> > for a bpf program. The 8 bytes space for dummy_tramp is sandwiched
> > between both above mentioned stubs. These 8 bytes contain memory
> > address of dummy trampoline during trampoline invocation which don't
> > correspond to any powerpc instructions. So, disassembly fails
> > resulting in failure of verifier selftests.
> > The following code snippet shows the problem with current arrangement
> > made for dummy_tramp_addr.
> > /* Out-of-line stub */
> > mflr r0
> > [b|bl] tramp
> > mtlr r0 //only with OOL
> > b bpf_func + 4
> > /* Long branch stub */
> > .long <dummy_tramp_addr> <---Invalid bytes sequence, disassembly fails
> > mflr r11
> > bcl 20,31,$+4
> > mflr r12
> > ld r12, -8-SZL(r12)
> > mtctr r12
> > mtlr r11 //retain ftrace ABI
> > bctr
> >
> > Consider test program binary of size 112 bytes:
> > 0: 00000060 10004de8 00002039 f8ff21f9 81ff21f8 7000e1fb 3000e13b
> > 28: 3000e13b 2a006038 f8ff7ff8 00000039 7000e1eb 80002138 7843037d
> > 56: 2000804e a602087c 00000060 a603087c bcffff4b c0341d00 000000c0
> > 84: a602687d 05009f42 a602887d f0ff8ce9 a603897d a603687d 2004804e
> >
> > Disassembly output of above binary for ppc64le:
> > pc:0 left:112 00 00 00 60 : nop
> > pc:4 left:108 10 00 4d e8 : ld 2, 16(13)
> > pc:8 left:104 00 00 20 39 : li 9, 0
> > pc:12 left:100 f8 ff 21 f9 : std 9, -8(1)
> > pc:16 left:96 81 ff 21 f8 : stdu 1, -128(1)
> > pc:20 left:92 70 00 e1 fb : std 31, 112(1)
> > pc:24 left:88 30 00 e1 3b : addi 31, 1, 48
> > pc:28 left:84 30 00 e1 3b : addi 31, 1, 48
> > pc:32 left:80 2a 00 60 38 : li 3, 42
> > pc:36 left:76 f8 ff 7f f8 : std 3, -8(31)
> > pc:40 left:72 00 00 00 39 : li 8, 0
> > pc:44 left:68 70 00 e1 eb : ld 31, 112(1)
> > pc:48 left:64 80 00 21 38 : addi 1, 1, 128
> > pc:52 left:60 78 43 03 7d : mr 3, 8
> > pc:56 left:56 20 00 80 4e : blr
> > pc:60 left:52 a6 02 08 7c : mflr 0
> > pc:64 left:48 00 00 00 60 : nop
> > pc:68 left:44 a6 03 08 7c : mtlr 0
> > pc:72 left:40 bc ff ff 4b : b .-68
> > pc:76 left:36 c0 34 1d 00 :
> > ...
> >
> > Failure log:
> > Can't disasm instruction at offset 76: c0 34 1d 00 00 00 00 c0 a6 02 68 7d 05 00 9f 42
> > --------------------------------------
> >
> > Observation:
> > Can't disasm instruction at offset 76 as this address has
> > ".long <dummy_tramp_addr>" (0xc0341d00000000c0)
> > But valid instructions follow at offset 84 onwards.
> >
> > Move the long branch address space to the bottom of the long
> > branch stub. This allows uninterrupted disassembly until the
> > last 8 bytes. Exclude these last bytes from the overall
> > program length to prevent failure in assembly generation.
> >
> > Following is disassembler output for same test program with moved down
> > dummy_tramp_addr field:
> > .....
> > .....
> > pc:68 left:44 a6 03 08 7c : mtlr 0
> > pc:72 left:40 bc ff ff 4b : b .-68
> > pc:76 left:36 a6 02 68 7d : mflr 11
> > pc:80 left:32 05 00 9f 42 : bcl 20, 31, .+4
> > pc:84 left:28 a6 02 88 7d : mflr 12
> > pc:88 left:24 14 00 8c e9 : ld 12, 20(12)
> > pc:92 left:20 a6 03 89 7d : mtctr 12
> > pc:96 left:16 a6 03 68 7d : mtlr 11
> > pc:100 left:12 20 04 80 4e : bctr
> > pc:104 left:8 c0 34 1d 00 :
> >
> > Failure log:
> > Can't disasm instruction at offset 104: c0 34 1d 00 00 00 00 c0
> > ---------------------------------------
> > Disassembly logic can truncate at 104, ignoring last 8 bytes.
> >
> > Update the dummy_tramp_addr field offset calculation from the end
> > of the program to reflect its new location, for bpf_arch_text_poke()
> > to update the actual trampoline's address in this field.
> >
> > [1] https://lore.kernel.org/all/20241030070850.1361304-18-hbathini@linux.ibm.com
> >
> > v9->v10:
> > Modified expected JIT instruction in selftest for
> > CONFIG_PPC_KERNEL_PCREL incase of PPC_LI64 instruction.
> > Fix for stale entries in exception table
> > Update ARCH_POWERPC64 enum value to 0x40 to resolve rebase
> > conflict with ARCH_LOONGARCH (0x20).
> >
> > v8->v9:
> > Dynamic pass handling until code keeps shrinking
> > Fix private stack memory leak
> >
> > v7->v8:
> > Fixed bot identified issues of alt_exit_addr and BPF_EXIT
> > Fixed 32-bit ppc function signature mismatch
> >
> > v6->v7:
> > Fixed JIT buffer overflow in case of large BPF progs
> > Addressed remaining bot comments
> >
> > v5->v6:
> > Changed alignment NOP emittion dependency on fimage layout
> > Adjust tail truncate length for 32-bit ppc
> > Addressed few minor bot comments
> >
> > v4->v5:
> > Handled alignment NOP emit logic and corresponding stub offsets
> > Handled image buffer overflow problem in last pass
> > Above changes took care of other bot reviews
> > Included LLVMDisposeMessage() for graceful freeing
> > Adjusted parameters in bpf_jit_build_fentry_stubs for ppc32
> > Adjusted expected JIT inst. in tailcall test for
> > CONFIG_PPC_KERNEL_PCREL config
> > Added fix patch at last for inaccurate use of cmplwi inst.
> >
> > v3->v4:
> > Changed logic for emitting alignment NOP
> >
> > v2->v3:
> > Removed fixed NOP from bottom of long branch stub
> > Rebased on top of bpf-next
> >
> > v1->v2:
> > Added fix-patch to correct memory alignment in-place
> > Moved the optional alignmnet NOP before OOL stub
> >
> > [v1]: https://lore.kernel.org/bpf/20260225013627.22098-1-adubey@linux.ibm.com
> > [v2]: https://lore.kernel.org/bpf/20260403004011.44417-1-adubey@linux.ibm.com
> > [v3]: https://lore.kernel.org/bpf/20260411221413.44304-1-adubey@linux.ibm.com
> > [v4]: https://lore.kernel.org/bpf/20260517214043.12975-1-adubey@linux.ibm.com
> > [v5]: https://lore.kernel.org/bpf/20260519233812.18787-1-adubey@linux.ibm.com
> > [v6]: https://lore.kernel.org/bpf/20260529015855.364704-1-adubey@linux.ibm.com
> > [v7]: https://lore.kernel.org/bpf/20260611153826.31187-1-adubey@linux.ibm.com
> > [v8]: https://lore.kernel.org/bpf/20260616164741.32252-1-adubey@linux.ibm.com
> > [v9]: https://lore.kernel.org/bpf/20260623231411.6216-1-adubey@linux.ibm.com/
> >
> > Abhishek Dubey (8):
> > powerpc/bpf: fix alignment of long branch trampoline addres to t
> > powerpc/bpf: Move out dummy_tramp_addr after Long branch stub
> > selftest/bpf: Fixing powerpc JIT disassembly failure
> > selftest/bpf: Enable verifier selftest for powerpc64
> > powerpc64/bpf: fix compare instruction emitted for tailcall
> > selftest/bpf: Add tailcall verifier selftest for powerpc64
> > powerpc/bpf: fix buffer overflow in JIT for large BPF programs
> > powerpc64/bpf: fix percpu private stack leak on JIT failure
> >
> > arch/powerpc/net/bpf_jit.h | 20 +++-
> > arch/powerpc/net/bpf_jit_comp.c | 102 +++++++++++++-----
> > arch/powerpc/net/bpf_jit_comp32.c | 7 +-
> > arch/powerpc/net/bpf_jit_comp64.c | 15 +--
> > .../selftests/bpf/jit_disasm_helpers.c | 25 ++++-
> > tools/testing/selftests/bpf/progs/bpf_misc.h | 1 +
> > .../bpf/progs/verifier_tailcall_jit.c | 74 +++++++++++++
> > tools/testing/selftests/bpf/test_loader.c | 5 +
> > 8 files changed, 209 insertions(+), 40 deletions(-)
> >
>
> Alexei, Maddy,
>
> Given this has changes in common code too, should this go via bpf tree?
> If yes, @Saket can you post the next revision with bpf tag to make
> it explicit...
>
> - Hari
I have sent the v11 for this series
https://lore.kernel.org/all/27ec08c30f6c37b3f25ba735f9cd7f81ff9e98d5.1786099877.git.skb99@linux.ibm.com/
- Saket
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2026-08-07 11:47 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-08-05 6:06 [PATCH v10 0/8] powerpc/bpf: address missing verifier selftest coverage Saket Kumar Bhaskar
2026-08-06 17:34 ` Hari Bathini
2026-08-07 3:21 ` Madhavan Srinivasan
2026-08-07 11:47 ` Saket Kumar Bhaskar
2026-08-07 11:42 ` [PATCH v11 " Saket Kumar Bhaskar
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