Commit Graph

99 Commits

Author SHA1 Message Date
Xu Kuohai
d9ef13f727 bpf: Pass bpf_verifier_env to JIT
Pass bpf_verifier_env to bpf_int_jit_compile(). The follow-up patch will
use env->insn_aux_data in the JIT stage to detect indirect jump targets.

Since bpf_prog_select_runtime() can be called by cbpf and lib/test_bpf.c
code without verifier, introduce helper __bpf_prog_select_runtime()
to accept the env parameter.

Remove the call to bpf_prog_select_runtime() in bpf_prog_load(), and
switch to call __bpf_prog_select_runtime() in the verifier, with env
variable passed. The original bpf_prog_select_runtime() is preserved for
cbpf and lib/test_bpf.c, where env is NULL.

Now all constants blinding calls are moved into the verifier, except
the cbpf and lib/test_bpf.c cases. The instructions arrays are adjusted
by bpf_patch_insn_data() function for normal cases, so there is no need
to call adjust_insn_arrays() in bpf_jit_blind_constants(). Remove it.

Reviewed-by: Anton Protopopov <a.s.protopopov@gmail.com> # v8
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com> # v12
Acked-by: Hengqi Chen <hengqi.chen@gmail.com> # v14
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20260416064341.151802-3-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-04-16 07:03:40 -07:00
Xu Kuohai
d3e945223e bpf: Move constants blinding out of arch-specific JITs
During the JIT stage, constants blinding rewrites instructions but only
rewrites the private instruction copy of the JITed subprog, leaving the
global env->prog->insnsi and env->insn_aux_data untouched. This causes a
mismatch between subprog instructions and the global state, making it
difficult to use the global data in the JIT.

To avoid this mismatch, and given that all arch-specific JITs already
support constants blinding, move it to the generic verifier code, and
switch to rewrite the global env->prog->insnsi with the global states
adjusted, as other rewrites in the verifier do.

This removes the constants blinding calls in each JIT, which are largely
duplicated code across architectures.

Since constants blinding is only required for JIT, and there are two
JIT entry functions, jit_subprogs() for BPF programs with multiple
subprogs and bpf_prog_select_runtime() for programs with no subprogs,
move the constants blinding invocation into these two functions.

In the verifier path, bpf_patch_insn_data() is used to keep global
verifier auxiliary data in sync with patched instructions. A key
question is whether this global auxiliary data should be restored
on the failure path.

Besides instructions, bpf_patch_insn_data() adjusts:
  - prog->aux->poke_tab
  - env->insn_array_maps
  - env->subprog_info
  - env->insn_aux_data

For prog->aux->poke_tab, it is only used by JIT or only meaningful after
JIT succeeds, so it does not need to be restored on the failure path.

For env->insn_array_maps, when JIT fails, programs using insn arrays
are rejected by bpf_insn_array_ready() due to missing JIT addresses.
Hence, env->insn_array_maps is only meaningful for JIT and does not need
to be restored.

For subprog_info, if jit_subprogs fails and CONFIG_BPF_JIT_ALWAYS_ON
is not enabled, kernel falls back to interpreter. In this case,
env->subprog_info is used to determine subprogram stack depth. So it
must be restored on failure.

For env->insn_aux_data, it is freed by clear_insn_aux_data() at the
end of bpf_check(). Before freeing, clear_insn_aux_data() loops over
env->insn_aux_data to release jump targets recorded in it. The loop
uses env->prog->len as the array length, but this length no longer
matches the actual size of the adjusted env->insn_aux_data array after
constants blinding.

To address it, a simple approach is to keep insn_aux_data as adjusted
after failure, since it will be freed shortly, and record its actual size
for the loop in clear_insn_aux_data(). But since clear_insn_aux_data()
uses the same index to loop over both env->prog->insnsi and env->insn_aux_data,
this approach results in incorrect index for the insnsi array. So an
alternative approach is adopted: clone the original env->insn_aux_data
before blinding and restore it after failure, similar to env->prog.

For classic BPF programs, constants blinding works as before since it
is still invoked from bpf_prog_select_runtime().

Reviewed-by: Anton Protopopov <a.s.protopopov@gmail.com> # v8
Reviewed-by: Hari Bathini <hbathini@linux.ibm.com> # powerpc jit
Reviewed-by: Pu Lehui <pulehui@huawei.com> # riscv jit
Acked-by: Hengqi Chen <hengqi.chen@gmail.com> # loongarch jit
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20260416064341.151802-2-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-04-16 07:03:40 -07:00
Abhishek Dubey
1e4bac7eb9 powerpc/bpf: Add support for instruction array
On loading the BPF program, the verifier might adjust/omit some
instructions. The adjusted instruction offset is accounted in the
map containing original instruction -> xlated mapping. This patch
add ppc64 JIT support to additionally build the xlated->jitted
mapping for every instruction present in instruction array. This
change is needed to enable support for indirect jumps, added in a
subsequent patch.

Invoke bpf_prog_update_insn_ptrs() with offset pair of xlated_offset
and jited_offset. The offset mapping is already available, which is
being used for bpf_prog_fill_jited_linfo() and can be directly used
for bpf_prog_update_insn_ptrs() as well.

Additional details present at:

commit b4ce5923e7 ("bpf, x86: add new map type: instructions array")

Signed-off-by: Abhishek Dubey <adubey@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260401152133.42544-2-adubey@linux.ibm.com
2026-04-03 14:14:25 +05:30
Abhishek Dubey
92258b5bf1 powerpc32/bpf: Add fsession support
Extend JIT support of fsession in powerpc64 trampoline, since
ppc64 and ppc32 shares common trampoline implementation.
Arch specific helpers handle 64-bit data copy using 32 bit regs.

Need to validate fsession support along with trampoline support.

Signed-off-by: Abhishek Dubey <adubey@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260401141043.41513-2-adubey@linux.ibm.com
2026-04-03 14:10:48 +05:30
Abhishek Dubey
6fab063bd8 powerpc64/bpf: Implement fsession support
Implement JIT support for fsession in powerpc64 trampoline.
The trampoline stack now accommodate session cookies and
function metadata in place of function argument. fentry/fexit
programs consume corresponding function metadata. This mirrors
existing x86 behavior and enable session cookies on powerpc64.

# ./test_progs -t fsession
#135/1   fsession_test/fsession_test:OK
#135/2   fsession_test/fsession_reattach:OK
#135/3   fsession_test/fsession_cookie:OK
#135     fsession_test:OK
Summary: 1/3 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Abhishek Dubey <adubey@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260401141043.41513-1-adubey@linux.ibm.com
2026-04-03 14:10:48 +05:30
Abhishek Dubey
156d985123 powerpc64/bpf: Implement JIT support for private stack
Provision the private stack as a per-CPU allocation during
bpf_int_jit_compile(). Align the stack to 16 bytes and place guard
regions at both ends to detect runtime stack overflow and underflow.

Round the private stack size up to the nearest 16-byte boundary.
Make each guard region 16 bytes to preserve the required overall
16-byte alignment. When private stack is set, skip bpf stack size
accounting in kernel stack.

There is no stack pointer in powerpc. Stack referencing during JIT
is done using frame pointer. Frame pointer calculation goes like:

BPF frame pointer = Priv stack allocation start address +
                    Overflow guard +
                    Actual stack size defined by verifier

Memory layout:

High Addr          +--------------------------------------------------+
                   |                                                  |
                   | 16 bytes Underflow guard (0xEB9F12345678eb9fULL) |
                   |                                                  |
         BPF FP -> +--------------------------------------------------+
                   |                                                  |
                   | Private stack - determined by verifier           |
                   | 16-bytes aligned                                 |
                   |                                                  |
                   +--------------------------------------------------+
                   |                                                  |
Lower Addr         | 16 byte Overflow guard (0xEB9F12345678eb9fULL)   |
                   |                                                  |
Priv stack alloc ->+--------------------------------------------------+
start

Update BPF_REG_FP to point to the calculated offset within the
allocated private stack buffer. Now, BPF stack usage reference
in the allocated private stack.

Signed-off-by: Abhishek Dubey <adubey@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260401103215.104438-1-adubey@linux.ibm.com
2026-04-03 14:09:43 +05:30
Hari Bathini
01b6ac7272 powerpc64/bpf: fix kfunc call support
Commit 61688a82e0 ("powerpc/bpf: enable kfunc call") inadvertently
enabled kfunc call support for 32-bit powerpc but that support will
not be possible until ABI mismatch between 32-bit powerpc and eBPF is
handled in 32-bit powerpc JIT code. Till then, advertise support only
for 64-bit powerpc. Also, in powerpc ABI, caller needs to extend the
arguments properly based on signedness. The JIT code is responsible
for handling this explicitly for kfunc calls as verifier can't handle
this for each architecture-specific ABI needs. But this was not taken
care of while kfunc call support was enabled for powerpc. Fix it by
handling this with bpf_jit_find_kfunc_model() and using zero_extend()
& sign_extend() helper functions.

Fixes: 61688a82e0 ("powerpc/bpf: enable kfunc call")
Cc: stable@vger.kernel.org
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260303181031.390073-7-hbathini@linux.ibm.com
2026-03-07 16:02:26 +05:30
Hari Bathini
2d347d10f8 powerpc64/bpf: remove BPF redzone protection in trampoline stack
Since bpf2bpf tailcall support is enabled for 64-bit powerpc with
kernel commit 2ed2d8f6fb ("powerpc64/bpf: Support tailcalls with
subprogs"), 'tailcalls/tailcall_bpf2bpf_hierarchy_fexit' BPF selftest
is triggering "corrupted stack end detected inside scheduler" with the
config option CONFIG_SCHED_STACK_END_CHECK enabled. While reviewing
the stack layout for BPF trampoline, observed that the dummy frame is
trying to protect the redzone of BPF program. This is because tail
call info and NVRs save area are in redzone at the time of tailcall
as the current BPF program stack frame is teared down before the
tailcall. But saving this redzone in the dummy frame of trampoline
is unnecessary because of the follow reasons:

  1) Firstly, trampoline can be attached to BPF entry/main program
     or subprog. But prologue part of the BPF entry/main program,
     where the trampoline attachpoint is, is skipped during tailcall.
     So, protecting the redzone does not arise when the trampoline is
     not even triggered in this scenario.
  2) In case of subprog, the caller's stackframe is already setup
     and the subprog's stackframe is yet to be setup. So, nothing
     on the redzone to be protected.

Also, using dummy frame in BPF trampoline, wastes critically scarce
kernel stack space, especially in tailcall sequence, for marginal
benefit in stack unwinding. So, drop setting up the dummy frame.
Instead, save return address in bpf trampoline frame and use it as
appropriate. Pruning this unnecessary stack usage mitigates the
likelihood of stack overflow in scenarios where bpf2bpf tailcalls
and fexit programs are mixed.

Reported-by: Saket Kumar Bhaskar <skb99@linux.ibm.com>
Fixes: 2ed2d8f6fb ("powerpc64/bpf: Support tailcalls with subprogs")
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260303181031.390073-5-hbathini@linux.ibm.com
2026-03-07 16:02:26 +05:30
Hari Bathini
3727d6ec13 powerpc64/bpf: use consistent tailcall offset in trampoline
Ideally, the offset used to load the tail call info field and to find
the pass by reference address for tail call field should be the same.
But while setting up the tail call info in the trampoline, this was
not followed. This can be misleading and can lead to unpredictable
results if and when bpf_has_stack_frame() ends up returning true
for trampoline frame. Since commit 15513beeb6 ("powerpc64/bpf:
Moving tail_call_cnt to bottom of frame") and commit 2ed2d8f6fb
("powerpc64/bpf: Support tailcalls with subprogs") ensured tail call
field is at the bottom of the stack frame for BPF programs as well as
BPF trampoline, avoid relying on bpf_jit_stack_tailcallinfo_offset()
and bpf_has_stack_frame() for trampoline frame and always calculate
tail call field offset with reference to older frame.

Fixes: 2ed2d8f6fb ("powerpc64/bpf: Support tailcalls with subprogs")
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260303181031.390073-4-hbathini@linux.ibm.com
2026-03-07 16:02:26 +05:30
Hari Bathini
157820264a powerpc64/bpf: fix the address returned by bpf_get_func_ip
bpf_get_func_ip() helper function returns the address of the traced
function. It relies on the IP address stored at ctx - 16 by the bpf
trampoline. On 64-bit powerpc, this address is recovered from LR
accounting for OOL trampoline. But the address stored here was off
by 4-bytes. Ensure the address is the actual start of the traced
function.

Reported-by: Abhishek Dubey <adubey@linux.ibm.com>
Fixes: d243b62b7b ("powerpc64/bpf: Add support for bpf trampolines")
Cc: stable@vger.kernel.org
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260303181031.390073-3-hbathini@linux.ibm.com
2026-03-07 16:02:26 +05:30
Linus Torvalds
bf4afc53b7 Convert 'alloc_obj' family to use the new default GFP_KERNEL argument
This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21 17:09:51 -08:00
Kees Cook
69050f8d6d treewide: Replace kmalloc with kmalloc_obj for non-scalar types
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-21 01:02:28 -08:00
Linus Torvalds
136114e0ab Merge tag 'mm-nonmm-stable-2026-02-12-10-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:

 - "ocfs2: give ocfs2 the ability to reclaim suballocator free bg" saves
   disk space by teaching ocfs2 to reclaim suballocator block group
   space (Heming Zhao)

 - "Add ARRAY_END(), and use it to fix off-by-one bugs" adds the
   ARRAY_END() macro and uses it in various places (Alejandro Colomar)

 - "vmcoreinfo: support VMCOREINFO_BYTES larger than PAGE_SIZE" makes
   the vmcore code future-safe, if VMCOREINFO_BYTES ever exceeds the
   page size (Pnina Feder)

 - "kallsyms: Prevent invalid access when showing module buildid" cleans
   up kallsyms code related to module buildid and fixes an invalid
   access crash when printing backtraces (Petr Mladek)

 - "Address page fault in ima_restore_measurement_list()" fixes a
   kexec-related crash that can occur when booting the second-stage
   kernel on x86 (Harshit Mogalapalli)

 - "kho: ABI headers and Documentation updates" updates the kexec
   handover ABI documentation (Mike Rapoport)

 - "Align atomic storage" adds the __aligned attribute to atomic_t and
   atomic64_t definitions to get natural alignment of both types on
   csky, m68k, microblaze, nios2, openrisc and sh (Finn Thain)

 - "kho: clean up page initialization logic" simplifies the page
   initialization logic in kho_restore_page() (Pratyush Yadav)

 - "Unload linux/kernel.h" moves several things out of kernel.h and into
   more appropriate places (Yury Norov)

 - "don't abuse task_struct.group_leader" removes the usage of
   ->group_leader when it is "obviously unnecessary" (Oleg Nesterov)

 - "list private v2 & luo flb" adds some infrastructure improvements to
   the live update orchestrator (Pasha Tatashin)

* tag 'mm-nonmm-stable-2026-02-12-10-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (107 commits)
  watchdog/hardlockup: simplify perf event probe and remove per-cpu dependency
  procfs: fix missing RCU protection when reading real_parent in do_task_stat()
  watchdog/softlockup: fix sample ring index wrap in need_counting_irqs()
  kcsan, compiler_types: avoid duplicate type issues in BPF Type Format
  kho: fix doc for kho_restore_pages()
  tests/liveupdate: add in-kernel liveupdate test
  liveupdate: luo_flb: introduce File-Lifecycle-Bound global state
  liveupdate: luo_file: Use private list
  list: add kunit test for private list primitives
  list: add primitives for private list manipulations
  delayacct: fix uapi timespec64 definition
  panic: add panic_force_cpu= parameter to redirect panic to a specific CPU
  netclassid: use thread_group_leader(p) in update_classid_task()
  RDMA/umem: don't abuse current->group_leader
  drm/pan*: don't abuse current->group_leader
  drm/amd: kill the outdated "Only the pthreads threading model is supported" checks
  drm/amdgpu: don't abuse current->group_leader
  android/binder: use same_thread_group(proc->tsk, current) in binder_mmap()
  android/binder: don't abuse current->group_leader
  kho: skip memoryless NUMA nodes when reserving scratch areas
  ...
2026-02-12 12:13:01 -08:00
Abhishek Dubey
c169930292 powerpc64/bpf: Support exceptions
The modified prologue/epilogue generation code now
enables exception-callback to use the stack frame of
the program marked as exception boundary, where callee
saved registers are stored.

As per ppc64 ABIv2 documentation[1], r14-r31 are callee
saved registers. BPF programs on ppc64 already saves
r26-r31 registers. Saving the remaining set of callee
saved registers(r14-r25) is handled in the next patch.

[1] https://ftp.rtems.org/pub/rtems/people/sebh/ABI64BitOpenPOWERv1.1_16July2015_pub.pdf

Signed-off-by: Abhishek Dubey <adubey@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260124075223.6033-6-adubey@linux.ibm.com
2026-01-29 09:06:01 +05:30
Abhishek Dubey
88cb7f4034 powerpc64/bpf: Avoid tailcall restore from trampoline
Back propagation of tailcall count is no longer needed for
powerpc64 due to use of reference, which updates the tailcall
count in the tail_call_info field in the frame of the main
program only.

Back propagation is still required for 32-bit powerpc.

Signed-off-by: Abhishek Dubey <adubey@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260124075223.6033-4-adubey@linux.ibm.com
2026-01-29 09:06:00 +05:30
Abhishek Dubey
2ed2d8f6fb powerpc64/bpf: Support tailcalls with subprogs
Enable tailcalls support in subprogs by passing tail call count as
reference instead of value. The actual tailcall count is always
maintained in the tailcall field present in the frame of main
function (also called entry function). The tailcall field in the
stack frame of subprogs contains reference to the tailcall field
in the stack frame of main BPF program. Accordingly, rename
tail_call_cnt field in the stack layout to tail_call_info.

Signed-off-by: Abhishek Dubey <adubey@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260124075223.6033-3-adubey@linux.ibm.com
2026-01-29 09:06:00 +05:30
Abhishek Dubey
15513beeb6 powerpc64/bpf: Moving tail_call_cnt to bottom of frame
To support tailcalls in subprogs, tail_call_cnt needs to be on the BPF
trampoline stack frame. In a regular BPF program or subprog stack
frame, the position of tail_call_cnt is after the NVR save area
(BPF_PPC_STACK_SAVE). To avoid complex logic in deducing offset for
tail_call_cnt, it has to be kept at the same offset on the trampoline
frame as well. But doing that wastes nearly all of BPF_PPC_STACK_SAVE
bytes on the BPF trampoline stack frame as the NVR save area is not
the same for BPF trampoline and regular BPF programs. Address this by
moving tail_call_cnt to the bottom of the frame.

This change avoids the need to account for BPF_PPC_STACK_SAVE bytes
in the BPF trampoline stack frame when support for tailcalls in BPF
subprogs is added later. Also, this change makes offset calculation
of tail_call_cnt field simpler all across.

Signed-off-by: Abhishek Dubey <adubey@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260124075223.6033-2-adubey@linux.ibm.com
2026-01-29 09:06:00 +05:30
Petr Mladek
cd6735896d kallsyms/bpf: rename __bpf_address_lookup() to bpf_address_lookup()
bpf_address_lookup() has been used only in kallsyms_lookup_buildid().  It
was supposed to set @modname and @modbuildid when the symbol was in a
module.

But it always just cleared @modname because BPF symbols were never in a
module.  And it did not clear @modbuildid because the pointer was not
passed.

The wrapper is no longer needed.  Both @modname and @modbuildid are now
always initialized to NULL in kallsyms_lookup_buildid().

Remove the wrapper and rename __bpf_address_lookup() to
bpf_address_lookup() because this variant is used everywhere.

[akpm@linux-foundation.org: fix loongarch]
Link: https://lkml.kernel.org/r/20251128135920.217303-6-pmladek@suse.com
Fixes: 9294523e37 ("module: add printk formats to add module build ID to stacktraces")
Signed-off-by: Petr Mladek <pmladek@suse.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Aaron Tomlin <atomlin@atomlin.com>
Cc: Daniel Borkman <daniel@iogearbox.net>
Cc: Daniel Gomez <da.gomez@samsung.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Luis Chamberalin <mcgrof@kernel.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20 19:44:22 -08:00
Saket Kumar Bhaskar
20ab1d1126 powerpc64/bpf: Inline bpf_get_smp_processor_id() and bpf_get_current_task/_btf()
Inline the calls to bpf_get_smp_processor_id() and bpf_get_current_task/_btf()
in the powerpc bpf jit.

powerpc saves the Logical processor number (paca_index) and pointer
to current task (__current) in paca.

Here is how the powerpc JITed assembly changes after this commit:

Before:

cpu = bpf_get_smp_processor_id();

addis 12, 2, -517
addi 12, 12, -29456
mtctr 12
bctrl
mr	8, 3

After:

cpu = bpf_get_smp_processor_id();

lhz 8, 8(13)

To evaluate the performance improvements introduced by this change,
the benchmark described in [1] was employed.

+---------------+-------------------+-------------------+--------------+
|      Name     |      Before       |        After      |   % change   |
|---------------+-------------------+-------------------+--------------|
| glob-arr-inc  | 40.701 ± 0.008M/s | 55.207 ± 0.021M/s |   + 35.64%   |
| arr-inc       | 39.401 ± 0.007M/s | 56.275 ± 0.023M/s |   + 42.42%   |
| hash-inc      | 24.944 ± 0.004M/s | 26.212 ± 0.003M/s |   +  5.08%   |
+---------------+-------------------+-------------------+--------------+

[1] https://github.com/anakryiko/linux/commit/8dec900975ef

Reviewed-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Saket Kumar Bhaskar <skb99@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/89abfdd6f6721fbe7897865e74f2f691e5f7824a.1765343385.git.skb99@linux.ibm.com
2026-01-07 09:32:40 +05:30
Saket Kumar Bhaskar
58a075adf3 powerpc64/bpf: Support internal-only MOV instruction to resolve per-CPU addrs
With the introduction of commit 7bdbf74463 ("bpf: add special
internal-only MOV instruction to resolve per-CPU addrs"),
a new BPF instruction BPF_MOV64_PERCPU_REG has been added to
resolve absolute addresses of per-CPU data from their per-CPU
offsets. This update requires enabling support for this
instruction in the powerpc JIT compiler.

As of commit 7a0268fa1a ("[PATCH] powerpc/64: per cpu data
optimisations"), the per-CPU data offset for the CPU is stored in
the paca.

To support this BPF instruction in the powerpc JIT, the following
powerpc instructions are emitted:
if (IS_ENABLED(CONFIG_SMP))
ld tmp1_reg, 48(13)		//Load per-CPU data offset from paca(r13) in tmp1_reg.
add dst_reg, src_reg, tmp1_reg	//Add the per cpu offset to the dst.
else if (src_reg != dst_reg)
mr dst_reg, src_reg		//Move src_reg to dst_reg, if src_reg != dst_reg

To evaluate the performance improvements introduced by this change,
the benchmark described in [1] was employed.

Before Change:
glob-arr-inc   :   41.580 ± 0.034M/s
arr-inc        :   39.592 ± 0.055M/s
hash-inc       :   25.873 ± 0.012M/s

After Change:
glob-arr-inc   :   42.024 ± 0.049M/s
arr-inc        :   55.447 ± 0.031M/s
hash-inc       :   26.565 ± 0.014M/s

[1] https://github.com/anakryiko/linux/commit/8dec900975ef

Reviewed-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Saket Kumar Bhaskar <skb99@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/667fdaa19c1564141f6cd82e75b2be86a42c0f96.1765343385.git.skb99@linux.ibm.com
2026-01-07 09:32:40 +05:30
Menglong Dong
ae4a3160d1 bpf: specify the old and new poke_type for bpf_arch_text_poke
In the origin logic, the bpf_arch_text_poke() assume that the old and new
instructions have the same opcode. However, they can have different opcode
if we want to replace a "call" insn with a "jmp" insn.

Therefore, add the new function parameter "old_t" along with the "new_t",
which are used to indicate the old and new poke type. Meanwhile, adjust
the implement of bpf_arch_text_poke() for all the archs.

"BPF_MOD_NOP" is added to make the code more readable. In
bpf_arch_text_poke(), we still check if the new and old address is NULL to
determine if nop insn should be used, which I think is more safe.

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Link: https://lore.kernel.org/r/20251118123639.688444-6-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-11-24 09:47:03 -08:00
Saket Kumar Bhaskar
0c1da35b01 powerpc64/bpf: Implement PROBE_ATOMIC instructions
powerpc supports BPF atomic operations using a loop around
Load-And-Reserve(LDARX/LWARX) and Store-Conditional(STDCX/STWCX)
instructions gated by sync instructions to enforce full ordering.

To implement arena_atomics, arena vm start address is added to the
dst_reg to be used for both the LDARX/LWARX and STDCX/STWCX instructions.
Further, an exception table entry is added for LDARX/LWARX
instruction to land after the loop on fault. At the end of sequence,
dst_reg is restored by subtracting arena vm start address.

bpf_jit_supports_insn() is introduced to selectively enable instruction
support as in other architectures like x86 and arm64.

Reviewed-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Saket Kumar Bhaskar <skb99@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250904100835.1100423-5-skb99@linux.ibm.com
2025-09-06 15:49:44 +05:30
Saket Kumar Bhaskar
a2485d06ca powerpc64/bpf: Implement bpf_addr_space_cast instruction
LLVM generates bpf_addr_space_cast instruction while translating
pointers between native (zero) address space and
__attribute__((address_space(N))). The addr_space=0 is reserved as
bpf_arena address space.

rY = addr_space_cast(rX, 0, 1) is processed by the verifier and
converted to normal 32-bit move: wX = wY.

rY = addr_space_cast(rX, 1, 0) : used to convert a bpf arena pointer to
a pointer in the userspace vma. This has to be converted by the JIT.

PPC_RAW_RLDICL_DOT, a variant of PPC_RAW_RLDICL is introduced to set
condition register as well.

Reviewed-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Saket Kumar Bhaskar <skb99@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250904100835.1100423-3-skb99@linux.ibm.com
2025-09-06 15:49:43 +05:30
Saket Kumar Bhaskar
47c7f3b703 powerpc64/bpf: Implement PROBE_MEM32 pseudo instructions
Add support for [LDX | STX | ST], PROBE_MEM32, [B | H | W | DW]
instructions.  They are similar to PROBE_MEM instructions with the
following differences:
- PROBE_MEM32 supports store.
- PROBE_MEM32 relies on the verifier to clear upper 32-bit of the
src/dst register
- PROBE_MEM32 adds 64-bit kern_vm_start address (which is stored in _R26
in the prologue). Due to bpf_arena constructions such _R26 + reg +
off16 access is guaranteed to be within arena virtual range, so no
address check at run-time.
- PROBE_MEM32 allows STX and ST. If they fault the store is a nop. When
LDX faults the destination register is zeroed.

To support these on powerpc, we do tmp1 = _R26 + src/dst reg and then use
tmp1 as the new src/dst register. This allows us to reuse most of the
code for normal [LDX | STX | ST].

Additionally, bpf_jit_emit_probe_mem_store() is introduced to emit
instructions for storing memory values depending on the size (byte,
halfword, word, doubleword).

Stack layout is adjusted to introduce a new NVR (_R26) and to make
BPF_PPC_STACKFRAME quadword aligned (local_tmp_var is increased by
8 bytes).

Reviewed-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Saket Kumar Bhaskar <skb99@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250904100835.1100423-2-skb99@linux.ibm.com
2025-09-06 15:49:43 +05:30
Hari Bathini
59ba025948 powerpc/bpf: fix JIT code size calculation of bpf trampoline
arch_bpf_trampoline_size() provides JIT size of the BPF trampoline
before the buffer for JIT'ing it is allocated. The total number of
instructions emitted for BPF trampoline JIT code depends on where
the final image is located. So, the size arrived at with the dummy
pass in arch_bpf_trampoline_size() can vary from the actual size
needed in  arch_prepare_bpf_trampoline().  When the instructions
accounted in  arch_bpf_trampoline_size() is less than the number of
instructions emitted during the actual JIT compile of the trampoline,
the below warning is produced:

  WARNING: CPU: 8 PID: 204190 at arch/powerpc/net/bpf_jit_comp.c:981 __arch_prepare_bpf_trampoline.isra.0+0xd2c/0xdcc

which is:

  /* Make sure the trampoline generation logic doesn't overflow */
  if (image && WARN_ON_ONCE(&image[ctx->idx] >
  			(u32 *)rw_image_end - BPF_INSN_SAFETY)) {

So, during the dummy pass, instead of providing some arbitrary image
location, account for maximum possible instructions if and when there
is a dependency with image location for JIT'ing.

Fixes: d243b62b7b ("powerpc64/bpf: Add support for bpf trampolines")
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Closes: https://lore.kernel.org/all/6168bfc8-659f-4b5a-a6fb-90a916dde3b3@linux.ibm.com/
Cc: stable@vger.kernel.org # v6.13+
Acked-by: Naveen N Rao (AMD) <naveen@kernel.org>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250422082609.949301-1-hbathini@linux.ibm.com
2025-04-29 11:04:27 +05:30
Linus Torvalds
42d9e8b7cc Merge tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:

 - Rework kfence support for the HPT MMU to work on systems with >= 16TB
   of RAM.

 - Remove the powerpc "maple" platform, used by the "Yellow Dog
   Powerstation".

 - Add support for DYNAMIC_FTRACE_WITH_CALL_OPS,
   DYNAMIC_FTRACE_WITH_DIRECT_CALLS & BPF Trampolines.

 - Add support for running KVM nested guests on Power11.

 - Other small features, cleanups and fixes.

Thanks to Amit Machhiwal, Arnd Bergmann, Christophe Leroy, Costa
Shulyupin, David Hunter, David Wang, Disha Goel, Gautam Menghani, Geert
Uytterhoeven, Hari Bathini, Julia Lawall, Kajol Jain, Keith Packard,
Lukas Bulwahn, Madhavan Srinivasan, Markus Elfring, Michal Suchanek,
Ming Lei, Mukesh Kumar Chaurasiya, Nathan Chancellor, Naveen N Rao,
Nicholas Piggin, Nysal Jan K.A, Paulo Miguel Almeida, Pavithra Prakash,
Ritesh Harjani (IBM), Rob Herring (Arm), Sachin P Bappalige, Shen
Lichuan, Simon Horman, Sourabh Jain, Thomas Weißschuh, Thorsten Blum,
Thorsten Leemhuis, Venkat Rao Bagalkote, Zhang Zekun, and zhang jiao.

* tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (89 commits)
  EDAC/powerpc: Remove PPC_MAPLE drivers
  powerpc/perf: Add per-task/process monitoring to vpa_pmu driver
  powerpc/kvm: Add vpa latency counters to kvm_vcpu_arch
  docs: ABI: sysfs-bus-event_source-devices-vpa-pmu: Document sysfs event format entries for vpa_pmu
  powerpc/perf: Add perf interface to expose vpa counters
  MAINTAINERS: powerpc: Mark Maddy as "M"
  powerpc/Makefile: Allow overriding CPP
  powerpc-km82xx.c: replace of_node_put() with __free
  ps3: Correct some typos in comments
  powerpc/kexec: Fix return of uninitialized variable
  macintosh: Use common error handling code in via_pmu_led_init()
  powerpc/powermac: Use of_property_match_string() in pmac_has_backlight_type()
  powerpc: remove dead config options for MPC85xx platform support
  powerpc/xive: Use cpumask_intersects()
  selftests/powerpc: Remove the path after initialization.
  powerpc/xmon: symbol lookup length fixed
  powerpc/ep8248e: Use %pa to format resource_size_t
  powerpc/ps3: Reorganize kerneldoc parameter names
  KVM: PPC: Book3S HV: Fix kmv -> kvm typo
  powerpc/sstep: make emulate_vsx_load and emulate_vsx_store static
  ...
2024-11-23 10:44:31 -08:00
Mike Rapoport (Microsoft)
0c3beacf68 asm-generic: introduce text-patching.h
Several architectures support text patching, but they name the header
files that declare patching functions differently.

Make all such headers consistently named text-patching.h and add an empty
header in asm-generic for architectures that do not support text patching.

Link: https://lkml.kernel.org/r/20241023162711.2579610-4-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Tested-by: kdevops <kdevops@lists.linux.dev>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Song Liu <song@kernel.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-07 14:25:15 -08:00
Naveen N Rao
d243b62b7b powerpc64/bpf: Add support for bpf trampolines
Add support for bpf_arch_text_poke() and arch_prepare_bpf_trampoline()
for 64-bit powerpc. While the code is generic, BPF trampolines are only
enabled on 64-bit powerpc. 32-bit powerpc will need testing and some
updates.

BPF Trampolines adhere to the existing ftrace ABI utilizing a
two-instruction profiling sequence, as well as the newer ABI utilizing a
three-instruction profiling sequence enabling return with a 'blr'. The
trampoline code itself closely follows x86 implementation.

BPF prog JIT is extended to mimic 64-bit powerpc approach for ftrace
having a single nop at function entry, followed by the function
profiling sequence out-of-line and a separate long branch stub for calls
to trampolines that are out of range. A dummy_tramp is provided to
simplify synchronization similar to arm64.

When attaching a bpf trampoline to a bpf prog, we can patch up to three
things:
- the nop at bpf prog entry to go to the out-of-line stub
- the instruction in the out-of-line stub to either call the bpf trampoline
directly, or to branch to the long_branch stub.
- the trampoline address before the long_branch stub.

We do not need any synchronization here since we always have a valid
branch target regardless of the order in which the above stores are
seen. dummy_tramp ensures that the long_branch stub goes to a valid
destination on other cpus, even when the branch to the long_branch stub
is seen before the updated trampoline address.

However, when detaching a bpf trampoline from a bpf prog, or if changing
the bpf trampoline address, we need synchronization to ensure that other
cpus can no longer branch into the older trampoline so that it can be
safely freed. bpf_tramp_image_put() uses rcu_tasks to ensure all cpus
make forward progress, but we still need to ensure that other cpus
execute isync (or some CSI) so that they don't go back into the
trampoline again. While here, update the stale comment that describes
the redzone usage in ppc64 BPF JIT.

Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241030070850.1361304-18-hbathini@linux.ibm.com
2024-10-31 11:00:55 +11:00
Rafael Passos
9919c5c98c bpf: remove unused parameter in bpf_jit_binary_pack_finalize
Fixes a compiler warning. the bpf_jit_binary_pack_finalize function
was taking an extra bpf_prog parameter that went unused.
This removves it and updates the callers accordingly.

Signed-off-by: Rafael Passos <rafael@rcpassos.me>
Link: https://lore.kernel.org/r/20240615022641.210320-2-rafael@rcpassos.me
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-20 19:50:26 -07:00
Hari Bathini
61688a82e0 powerpc/bpf: enable kfunc call
Currently, bpf jit code on powerpc assumes all the bpf functions and
helpers to be part of core kernel text. This is false for kfunc case,
as function addresses may not be part of core kernel text area. So,
add support for addresses that are not within core kernel text area
too, to enable kfunc support. Emit instructions based on whether the
function address is within core kernel text address or not, to retain
optimized instruction sequence where possible.

In case of PCREL, as a bpf function that is not within core kernel
text area is likely to go out of range with relative addressing on
kernel base, use PC relative addressing. If that goes out of range,
load the full address with PPC_LI64().

With addresses that are not within core kernel text area supported,
override bpf_jit_supports_kfunc_call() to enable kfunc support. Also,
override bpf_jit_supports_far_kfunc_call() to enable 64-bit pointers,
as an address offset can be more than 32-bit long on PPC64.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240502173205.142794-2-hbathini@linux.ibm.com
2024-05-06 22:05:18 +10:00
Hari Bathini
90d862f370 powerpc/bpf: use bpf_jit_binary_pack_[alloc|finalize|free]
Use bpf_jit_binary_pack_alloc in powerpc jit. The jit engine first
writes the program to the rw buffer. When the jit is done, the program
is copied to the final location with bpf_jit_binary_pack_finalize.
With multiple jit_subprogs, bpf_jit_free is called on some subprograms
that haven't got bpf_jit_binary_pack_finalize() yet. Implement custom
bpf_jit_free() like in commit 1d5f82d9dd ("bpf, x86: fix freeing of
not-finalized bpf_prog_pack") to call bpf_jit_binary_pack_finalize(),
if necessary. As bpf_flush_icache() is not needed anymore, remove it.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231020141358.643575-6-hbathini@linux.ibm.com
2023-10-23 20:33:19 +11:00
Hari Bathini
de04e40600 powerpc/bpf: rename powerpc64_jit_data to powerpc_jit_data
powerpc64_jit_data is a misnomer as it is meant for both ppc32 and
ppc64. Rename it to powerpc_jit_data.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231020141358.643575-5-hbathini@linux.ibm.com
2023-10-23 20:33:19 +11:00
Hari Bathini
033ffaf0af powerpc/bpf: implement bpf_arch_text_invalidate for bpf_prog_pack
Implement bpf_arch_text_invalidate and use it to fill unused part of
the bpf_prog_pack with trap instructions when a BPF program is freed.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231020141358.643575-4-hbathini@linux.ibm.com
2023-10-23 20:33:19 +11:00
Hari Bathini
6efc1675ac powerpc/bpf: implement bpf_arch_text_copy
bpf_arch_text_copy is used to dump JITed binary to RX page, allowing
multiple BPF programs to share the same page. Use the newly introduced
patch_instructions() to implement it.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231020141358.643575-3-hbathini@linux.ibm.com
2023-10-23 20:33:19 +11:00
Benjamin Gray
ddfb7d9db8 powerpc: Use NULL instead of 0 for null pointers
Sparse reports several uses of 0 for pointer arguments and comparisons.
Replace with NULL to better convey the intent. Remove entirely if a
comparison to follow the kernel style of implicit boolean conversions.

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231011053711.93427-5-bgray@linux.ibm.com
2023-10-19 17:12:47 +11:00
Hari Bathini
35a4b8ce4a powerpc/bpf: populate extable entries only during the last pass
Since commit 85e031154c ("powerpc/bpf: Perform complete extra passes
to update addresses"), two additional passes are performed to avoid
space and CPU time wastage on powerpc. But these extra passes led to
WARN_ON_ONCE() hits in bpf_add_extable_entry() as extable entries are
populated again, during the extra pass, without resetting the index.
Fix it by resetting entry index before repopulating extable entries,
if and when there is an additional pass.

Fixes: 85e031154c ("powerpc/bpf: Perform complete extra passes to update addresses")
Cc: stable@vger.kernel.org # v6.3+
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230425065829.18189-1-hbathini@linux.ibm.com
2023-05-15 15:40:31 +10:00
Christophe Leroy
85e031154c powerpc/bpf: Perform complete extra passes to update addresses
BPF core calls the jit compiler again for an extra pass in order
to properly set subprog addresses.

Unlike other architectures, powerpc only updates the addresses
during that extra pass. It means that holes must have been left
in the code in order to enable the maximum possible instruction
size.

In order to avoid waste of space, and waste of CPU time on powerpc
processors on which the NOP instruction is not 0-cycle, perform
two real additional passes.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d484a4ac95949ff55fc4344b674e7c0d3ddbfcd5.1675245773.git.christophe.leroy@csgroup.eu
2023-02-10 22:17:35 +11:00
Christophe Leroy
7d40aff821 powerpc: Replace PPC64_ELF_ABI_v{1/2} by CONFIG_PPC64_ELF_ABI_V{1/2}
Replace all uses of PPC64_ELF_ABI_v1 and PPC64_ELF_ABI_v2 by
resp CONFIG_PPC64_ELF_ABI_V1 and CONFIG_PPC64_ELF_ABI_V2.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ba13d59e8c50bc9aa6328f1c7f0c0d0278e0a3a7.1652074503.git.christophe.leroy@csgroup.eu
2022-05-19 23:11:29 +10:00
Linus Torvalds
1f1c153e40 Merge tag 'powerpc-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
 "Livepatch support for 32-bit is probably the standout new feature,
  otherwise mostly just lots of bits and pieces all over the board.

  There's a series of commits cleaning up function descriptor handling,
  which touches a few other arches as well as LKDTM. It has acks from
  Arnd, Kees and Helge.

  Summary:

   - Enforce kernel RO, and implement STRICT_MODULE_RWX for 603.

   - Add support for livepatch to 32-bit.

   - Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS.

   - Merge vdso64 and vdso32 into a single directory.

   - Fix build errors with newer binutils.

   - Add support for UADDR64 relocations, which are emitted by some
     toolchains. This allows powerpc to build with the latest lld.

   - Fix (another) potential userspace r13 corruption in transactional
     memory handling.

   - Cleanups of function descriptor handling & related fixes to LKDTM.

  Thanks to Abdul Haleem, Alexey Kardashevskiy, Anders Roxell, Aneesh
  Kumar K.V, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Bhaskar
  Chowdhury, Cédric Le Goater, Chen Jingwen, Christophe JAILLET,
  Christophe Leroy, Corentin Labbe, Daniel Axtens, Daniel Henrique
  Barboza, David Dai, Fabiano Rosas, Ganesh Goudar, Guo Zhengkui, Hangyu
  Hua, Haren Myneni, Hari Bathini, Igor Zhbanov, Jakob Koschel, Jason
  Wang, Jeremy Kerr, Joachim Wiberg, Jordan Niethe, Julia Lawall, Kajol
  Jain, Kees Cook, Laurent Dufour, Madhavan Srinivasan, Mamatha Inamdar,
  Maxime Bizon, Maxim Kiselev, Maxim Kochetkov, Michal Suchanek,
  Nageswara R Sastry, Nathan Lynch, Naveen N. Rao, Nicholas Piggin,
  Nour-eddine Taleb, Paul Menzel, Ping Fang, Pratik R. Sampat, Randy
  Dunlap, Ritesh Harjani, Rohan McLure, Russell Currey, Sachin Sant,
  Segher Boessenkool, Shivaprasad G Bhat, Sourabh Jain, Thierry Reding,
  Tobias Waldekranz, Tyrel Datwyler, Vaibhav Jain, Vladimir Oltean,
  Wedson Almeida Filho, and YueHaibing"

* tag 'powerpc-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (179 commits)
  powerpc/pseries: Fix use after free in remove_phb_dynamic()
  powerpc/time: improve decrementer clockevent processing
  powerpc/time: Fix KVM host re-arming a timer beyond decrementer range
  powerpc/tm: Fix more userspace r13 corruption
  powerpc/xive: fix return value of __setup handler
  powerpc/64: Add UADDR64 relocation support
  powerpc: 8xx: fix a return value error in mpc8xx_pic_init
  powerpc/ps3: remove unneeded semicolons
  powerpc/64: Force inlining of prevent_user_access() and set_kuap()
  powerpc/bitops: Force inlining of fls()
  powerpc: declare unmodified attribute_group usages const
  powerpc/spufs: Fix build warning when CONFIG_PROC_FS=n
  powerpc/secvar: fix refcount leak in format_show()
  powerpc/64e: Tie PPC_BOOK3E_64 to PPC_FSL_BOOK3E
  powerpc: Move C prototypes out of asm-prototypes.h
  powerpc/kexec: Declare kexec_paca static
  powerpc/smp: Declare current_set static
  powerpc: Cleanup asm-prototypes.c
  powerpc/ftrace: Use STK_GOT in ftrace_mprofile.S
  powerpc/ftrace: Regroup PPC64 specific operations in ftrace_mprofile.S
  ...
2022-03-25 09:39:36 -07:00
Naveen N. Rao
49c3af43e6 powerpc/bpf: Simplify bpf_to_ppc() and adopt it for powerpc64
Convert bpf_to_ppc() to a macro to help simplify its usage since
codegen_context is available in all places it is used. Adopt it also for
powerpc64 for uniformity and get rid of the global b2p structure.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/09f0540ce3e0cd4120b5b33993b5e73b6ef9e979.1644834730.git.naveen.n.rao@linux.vnet.ibm.com
2022-03-08 00:04:59 +11:00
Naveen N. Rao
43d636f8b4 powerpc64/bpf elfv1: Do not load TOC before calling functions
BPF helpers always reside in core kernel and all BPF programs use the
kernel TOC. As such, there is no need to load the TOC before calling
helpers or other BPF functions. Drop code to do the same.

Add a check to ensure we don't proceed if this assumption ever changes
in future.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a3cd3da4d24d95d845cd10382b1af083600c9074.1644834730.git.naveen.n.rao@linux.vnet.ibm.com
2022-03-08 00:04:58 +11:00
Naveen N. Rao
0ffdbce6f4 powerpc/bpf: Handle large branch ranges with BPF_EXIT
In some scenarios, it is possible that the program epilogue is outside
the branch range for a BPF_EXIT instruction. Instead of rejecting such
programs, emit epilogue as an alternate exit point from the program.
Track the location of the same so that subsequent exits can take either
of the two paths.

Reported-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/33aa2e92645a92712be23b18035a2c6dcb92ff8d.1644834730.git.naveen.n.rao@linux.vnet.ibm.com
2022-03-08 00:04:57 +11:00
Jakub Kicinski
1127170d45 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2022-02-09

We've added 126 non-merge commits during the last 16 day(s) which contain
a total of 201 files changed, 4049 insertions(+), 2215 deletions(-).

The main changes are:

1) Add custom BPF allocator for JITs that pack multiple programs into a huge
   page to reduce iTLB pressure, from Song Liu.

2) Add __user tagging support in vmlinux BTF and utilize it from BPF
   verifier when generating loads, from Yonghong Song.

3) Add per-socket fast path check guarding from cgroup/BPF overhead when
   used by only some sockets, from Pavel Begunkov.

4) Continued libbpf deprecation work of APIs/features and removal of their
   usage from samples, selftests, libbpf & bpftool, from Andrii Nakryiko
   and various others.

5) Improve BPF instruction set documentation by adding byte swap
   instructions and cleaning up load/store section, from Christoph Hellwig.

6) Switch BPF preload infra to light skeleton and remove libbpf dependency
   from it, from Alexei Starovoitov.

7) Fix architecture-agnostic macros in libbpf for accessing syscall
   arguments from BPF progs for non-x86 architectures,
   from Ilya Leoshkevich.

8) Rework port members in struct bpf_sk_lookup and struct bpf_sock to be
   of 16-bit field with anonymous zero padding, from Jakub Sitnicki.

9) Add new bpf_copy_from_user_task() helper to read memory from a different
   task than current. Add ability to create sleepable BPF iterator progs,
   from Kenny Yu.

10) Implement XSK batching for ice's zero-copy driver used by AF_XDP and
    utilize TX batching API from XSK buffer pool, from Maciej Fijalkowski.

11) Generate temporary netns names for BPF selftests to avoid naming
    collisions, from Hangbin Liu.

12) Implement bpf_core_types_are_compat() with limited recursion for
    in-kernel usage, from Matteo Croce.

13) Simplify pahole version detection and finally enable CONFIG_DEBUG_INFO_DWARF5
    to be selected with CONFIG_DEBUG_INFO_BTF, from Nathan Chancellor.

14) Misc minor fixes to libbpf and selftests from various folks.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (126 commits)
  selftests/bpf: Cover 4-byte load from remote_port in bpf_sk_lookup
  bpf: Make remote_port field in struct bpf_sk_lookup 16-bit wide
  libbpf: Fix compilation warning due to mismatched printf format
  selftests/bpf: Test BPF_KPROBE_SYSCALL macro
  libbpf: Add BPF_KPROBE_SYSCALL macro
  libbpf: Fix accessing the first syscall argument on s390
  libbpf: Fix accessing the first syscall argument on arm64
  libbpf: Allow overriding PT_REGS_PARM1{_CORE}_SYSCALL
  selftests/bpf: Skip test_bpf_syscall_macro's syscall_arg1 on arm64 and s390
  libbpf: Fix accessing syscall arguments on riscv
  libbpf: Fix riscv register names
  libbpf: Fix accessing syscall arguments on powerpc
  selftests/bpf: Use PT_REGS_SYSCALL_REGS in bpf_syscall_macro
  libbpf: Add PT_REGS_SYSCALL_REGS macro
  selftests/bpf: Fix an endianness issue in bpf_syscall_macro test
  bpf: Fix bpf_prog_pack build HPAGE_PMD_SIZE
  bpf: Fix leftover header->pages in sparc and powerpc code.
  libbpf: Fix signedness bug in btf_dump_array_data()
  selftests/bpf: Do not export subtest as standalone test
  bpf, x86_64: Fail gracefully on bpf_jit_binary_pack_finalize failures
  ...
====================

Link: https://lore.kernel.org/r/20220209210050.8425-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-09 18:40:56 -08:00
Song Liu
0f350231b5 bpf: Fix leftover header->pages in sparc and powerpc code.
Replace header->pages * PAGE_SIZE with new header->size.

Fixes: ed2d9e1a26 ("bpf: Use size instead of pages in bpf_binary_header")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220208220509.4180389-2-song@kernel.org
2022-02-08 14:52:05 -08:00
Naveen N. Rao
f9320c4999 powerpc/bpf: Update ldimm64 instructions during extra pass
These instructions are updated after the initial JIT, so redo codegen
during the extra pass. Rename bpf_jit_fixup_subprog_calls() to clarify
that this is more than just subprog calls.

Fixes: 69c087ba62 ("bpf: Add bpf_for_each_map_elem() helper")
Cc: stable@vger.kernel.org # v5.15
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7cc162af77ba918eb3ecd26ec9e7824bc44b1fae.1641468127.git.naveen.n.rao@linux.vnet.ibm.com
2022-01-15 12:21:24 +11:00
Hari Bathini
23b51916ee bpf ppc32: Add BPF_PROBE_MEM support for JIT
BPF load instruction with BPF_PROBE_MEM mode can cause a fault
inside kernel. Append exception table for such instructions
within BPF program.

Unlike other archs which uses extable 'fixup' field to pass dest_reg
and nip, BPF exception table on PowerPC follows the generic PowerPC
exception table design, where it populates both fixup and extable
sections within BPF program. fixup section contains 3 instructions,
first 2 instructions clear dest_reg (lower & higher 32-bit registers)
and last instruction jumps to next instruction in the BPF code.
extable 'insn' field contains relative offset of the instruction and
'fixup' field contains relative offset of the fixup entry. Example
layout of BPF program with extable present:

             +------------------+
             |                  |
             |                  |
   0x4020 -->| lwz   r28,4(r4)  |
             |                  |
             |                  |
   0x40ac -->| lwz  r3,0(r24)   |
             | lwz  r4,4(r24)   |
             |                  |
             |                  |
             |------------------|
   0x4278 -->| li  r28,0        |  \
             | li  r27,0        |  | fixup entry
             | b   0x4024       |  /
   0x4284 -->| li  r4,0         |
             | li  r3,0         |
             | b   0x40b4       |
             |------------------|
   0x4290 -->| insn=0xfffffd90  |  \ extable entry
             | fixup=0xffffffe4 |  /
   0x4298 -->| insn=0xfffffe14  |
             | fixup=0xffffffe8 |
             +------------------+

   (Addresses shown here are chosen random, not real)

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211012123056.485795-8-hbathini@linux.ibm.com
2021-11-25 11:25:32 +11:00
Ravi Bangoria
983bdc0245 bpf ppc64: Add BPF_PROBE_MEM support for JIT
BPF load instruction with BPF_PROBE_MEM mode can cause a fault
inside kernel. Append exception table for such instructions
within BPF program.

Unlike other archs which uses extable 'fixup' field to pass dest_reg
and nip, BPF exception table on PowerPC follows the generic PowerPC
exception table design, where it populates both fixup and extable
sections within BPF program. fixup section contains two instructions,
first instruction clears dest_reg and 2nd jumps to next instruction
in the BPF code. extable 'insn' field contains relative offset of
the instruction and 'fixup' field contains relative offset of the
fixup entry. Example layout of BPF program with extable present:

             +------------------+
             |                  |
             |                  |
   0x4020 -->| ld   r27,4(r3)   |
             |                  |
             |                  |
   0x40ac -->| lwz  r3,0(r4)    |
             |                  |
             |                  |
             |------------------|
   0x4280 -->| li  r27,0        |  \ fixup entry
             | b   0x4024       |  /
   0x4288 -->| li  r3,0         |
             | b   0x40b0       |
             |------------------|
   0x4290 -->| insn=0xfffffd90  |  \ extable entry
             | fixup=0xffffffec |  /
   0x4298 -->| insn=0xfffffe14  |
             | fixup=0xffffffec |
             +------------------+

   (Addresses shown here are chosen random, not real)

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211012123056.485795-6-hbathini@linux.ibm.com
2021-11-25 11:25:32 +11:00
Ravi Bangoria
04c04205bc bpf powerpc: Remove extra_pass from bpf_jit_build_body()
In case of extra_pass, usual JIT passes are always skipped. So,
extra_pass is always false while calling bpf_jit_build_body() and
can be removed.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211012123056.485795-3-hbathini@linux.ibm.com
2021-11-25 11:25:31 +11:00
Linus Torvalds
5c0b0c676a Merge tag 'powerpc-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:

 - Enable STRICT_KERNEL_RWX for Freescale 85xx platforms.

 - Activate CONFIG_STRICT_KERNEL_RWX by default, while still allowing it
   to be disabled.

 - Add support for out-of-line static calls on 32-bit.

 - Fix oopses doing bpf-to-bpf calls when STRICT_KERNEL_RWX is enabled.

 - Fix boot hangs on e5500 due to stale value in ESR passed to
   do_page_fault().

 - Fix several bugs on pseries in handling of device tree cache
   information for hotplugged CPUs, and/or during partition migration.

 - Various other small features and fixes.

Thanks to Alexey Kardashevskiy, Alistair Popple, Anatolij Gustschin,
Andrew Donnellan, Athira Rajeev, Bixuan Cui, Bjorn Helgaas, Cédric Le
Goater, Christophe Leroy, Daniel Axtens, Daniel Henrique Barboza, Denis
Kirjanov, Fabiano Rosas, Frederic Barrat, Gustavo A.  R.  Silva, Hari
Bathini, Jacques de Laval, Joel Stanley, Kai Song, Kajol Jain, Laurent
Vivier, Leonardo Bras, Madhavan Srinivasan, Nathan Chancellor, Nathan
Lynch, Naveen N.  Rao, Nicholas Piggin, Nick Desaulniers, Niklas
Schnelle, Oliver O'Halloran, Rob Herring, Russell Currey, Srikar
Dronamraju, Stan Johnson, Tyrel Datwyler, Uwe Kleine-König, Vasant
Hegde, Wan Jiabing, and Xiaoming Ni,

* tag 'powerpc-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (73 commits)
  powerpc/8xx: Fix Oops with STRICT_KERNEL_RWX without DEBUG_RODATA_TEST
  powerpc/32e: Ignore ESR in instruction storage interrupt handler
  powerpc/powernv/prd: Unregister OPAL_MSG_PRD2 notifier during module unload
  powerpc: Don't provide __kernel_map_pages() without ARCH_SUPPORTS_DEBUG_PAGEALLOC
  MAINTAINERS: Update powerpc KVM entry
  powerpc/xmon: fix task state output
  powerpc/44x/fsp2: add missing of_node_put
  powerpc/dcr: Use cmplwi instead of 3-argument cmpli
  KVM: PPC: Tick accounting should defer vtime accounting 'til after IRQ handling
  powerpc/security: Use a mutex for interrupt exit code patching
  powerpc/83xx/mpc8349emitx: Make mcu_gpiochip_remove() return void
  powerpc/fsl_booke: Fix setting of exec flag when setting TLBCAMs
  powerpc/book3e: Fix set_memory_x() and set_memory_nx()
  powerpc/nohash: Fix __ptep_set_access_flags() and ptep_set_wrprotect()
  powerpc/bpf: Fix write protecting JIT code
  selftests/powerpc: Use date instead of EPOCHSECONDS in mitigation-patching.sh
  powerpc/64s/interrupt: Fix check_return_regs_valid() false positive
  powerpc/boot: Set LC_ALL=C in wrapper script
  powerpc/64s: Default to 64K pages for 64 bit book3s
  Revert "powerpc/audit: Convert powerpc to AUDIT_ARCH_COMPAT_GENERIC"
  ...
2021-11-05 08:15:46 -07:00
Hari Bathini
44a8214de9 powerpc/bpf: Fix write protecting JIT code
Running program with bpf-to-bpf function calls results in data access
exception (0x300) with the below call trace:

  bpf_int_jit_compile+0x238/0x750 (unreliable)
  bpf_check+0x2008/0x2710
  bpf_prog_load+0xb00/0x13a0
  __sys_bpf+0x6f4/0x27c0
  sys_bpf+0x2c/0x40
  system_call_exception+0x164/0x330
  system_call_vectored_common+0xe8/0x278

as bpf_int_jit_compile() tries writing to write protected JIT code
location during the extra pass.

Fix it by holding off write protection of JIT code until the extra
pass, where branch target addresses fixup happens.

Fixes: 62e3d4210a ("powerpc/bpf: Write protect JIT code")
Cc: stable@vger.kernel.org # v5.14+
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211025055649.114728-1-hbathini@linux.ibm.com
2021-10-28 00:08:32 +11:00