powerpc/bpf: Some updates and cleanups #2561
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Master branch: 9c3de61 |
During the first pass, addrs[] is still being populated. So, all branches to following instructions will appear to be going to the start of the JIT program. Ignore branch range validation for such instructions and assume those to be in range. Branch range validation will happen during the second pass after addrs[] is setup properly. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
…ranges PPC_BCC() emits two instructions to accommodate scenarios where we need to branch outside the range of a conditional branch. PPC_BCC_SHORT() emits a single branch instruction and can be used when the branch is known to be within a conditional branch range. Convert some of the uses of PPC_BCC() in the powerpc BPF JIT over to PPC_BCC_SHORT() where we know the branch range. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
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>
Instead of saving and restoring LR before each invocation to bpf_stf_barrier(), set SEEN_FUNC flag so that we save/restore LR in prologue/epilogue. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
In preparation for preserving kernel toc in r2, switch BPF_REG_AX from r2 to r12. r12 is not used by bpf JIT except during external helper/bpf calls, or with BPF_NOSPEC. These sequences aren't emitted when BPF_REG_AX is used for constant blinding and other purposes. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Set macros to 1 so that they can be used with __is_defined(). Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
In preparation for using kernel TOC, load the same in r2 on entry. With elfv1, the kernel TOC is already setup by our caller. We adjust the number of instructions to skip on a tail call accordingly. We get rid of the #ifdef in bpf_jit_emit_tail_call() since FUNCTION_DESCR_SIZE is itself under a #ifdef. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
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>
When calling BPF helpers, we load the function address to call into a register. This can result in upto 5 instructions. Optimize this by instead using the kernel toc in r2 and adjusting offset to the BPF helper. This works since all BPF helpers are part of kernel text, and all BPF programs/functions utilize the kernel TOC. Further more: - load the actual function entry address in elf v1, rather than loading it through the function descriptor address. - load the Local Entry Point (LEP) in elf v2 skipping TOC setup. - consolidate code across elf abi v1 and v2 by using r12 on both. Reported-by: Anton Blanchard <anton@ozlabs.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
PPC_BL_ABS() is just doing a relative branch with link. The name suggests that it is for branching to an absolute address, which is incorrect. Rename the macro to a more appropriate PPC_BL(). Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
…F_[LD|STD] PPC_BPF_[LL|STL] are macros meant for scenarios where we may have to deal with a non-word aligned offset. Limit their usage to only those scenarios by converting the rest to just use PPC_BPF_[LD|STD]. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
All these macros now have a single user. Expand their usage in place. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
- PPC_EX32() is only used by ppc32 JIT. Move it to bpf_jit_comp32.c - PPC_LI64() is only valid in ppc64. #ifdef it - PPC_FUNC_ADDR() is not used anymore. Remove it. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
There is no need for a separate header anymore. Move the contents of bpf_jit64.h into bpf_jit_comp64.c Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Use _Rn macros to specify register names to make their usage clear. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
In bpf_jit_build_body(), the mapping of TMP_REG_1 and TMP_REG_2's bpf register to ppc register is evalulated at every use despite not changing. Instead, determine the ppc register once and store the result. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> [Rebased, converted additional usage sites] Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
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>
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Master branch: 9c3de61 |
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At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=614063 irrelevant now. Closing PR. |
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At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=614063 irrelevant now. Closing PR. |
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Pull request for series with
subject: powerpc/bpf: Some updates and cleanups
version: 1
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=614063