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2024-12-02LoongArch: BPF: Adjust the parameter of emit_jirl()Tiezhu Yang
The branch instructions beq, bne, blt, bge, bltu, bgeu and jirl belong to the format reg2i16, but the sequence of oprand is different for the instruction jirl. So adjust the parameter order of emit_jirl() to make it more readable correspond with the Instruction Set Architecture manual. Here are the instruction formats: beq rj, rd, offs16 bne rj, rd, offs16 blt rj, rd, offs16 bge rj, rd, offs16 bltu rj, rd, offs16 bgeu rj, rd, offs16 jirl rd, rj, offs16 Link: https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#branch-instructions Suggested-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-06-29LoongArch: Add larch_insn_gen_break() to generate break insnsTiezhu Yang
There exist various break insns such as BRK_KPROBE_BP, BRK_KPROBE_SSTEPBP, BRK_UPROBE_BP and BRK_UPROBE_XOLBP, add larch_insn_gen_break() to generate break insns simpler, this is preparation for later patch. Tested-by: Jeff Xie <xiehuan09@gmail.com> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-06-29LoongArch: Check for AMO instructions in insns_not_supported()Tiezhu Yang
Like llsc instructions, the atomic memory access instructions shouldn't be supported for probing, so check for them in insns_not_supported(). Closes: https://lore.kernel.org/all/SY4P282MB351877A70A0333C790FE85A5C09C9@SY4P282MB3518.AUSP282.PROD.OUTLOOK.COM/ Tested-by: Jeff Xie <xiehuan09@gmail.com> Reported-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-06-29LoongArch: Move three functions from kprobes.c to inst.cTiezhu Yang
The three functions insns_not_supported(), insns_need_simulation() and arch_simulate_insn() will be used for uprobes, move them from kprobes.c to inst.c, this is preparation for later patch, no functionality change. Tested-by: Jeff Xie <xiehuan09@gmail.com> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-06-29LoongArch: Add guard for the larch_insn_gen_xxx functionsWANG Rui
Add guard for the larch_insn_gen_xxx functions to verify whether the immediate operand is within the acceptable range. Signed-off-by: WANG Rui <wangrui@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-02-25LoongArch: Simulate branch and PC* instructionsTiezhu Yang
According to LoongArch Reference Manual, simulate branch and PC* instructions, this is preparation for later patch. Link: https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#branch-instructions Link: https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#_pcaddi_pcaddu121_pcaddu18l_pcalau12i Tested-by: Jeff Xie <xiehuan09@gmail.com> Co-developed-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-01-17LoongArch: Simplify larch_insn_gen_xxx implementationYouling Tang
Simplify larch_insn_gen_xxx implementation by reusing emit_xxx. Signed-off-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-12-14LoongArch: modules/ftrace: Initialize PLT at load timeQing Zhang
This patch implements ftrace trampolines through plt entry. Tested by forcing ftrace_make_call() to use the module PLT, and then loading up a module after setting up ftrace with: | echo ":mod:<module-name>" > set_ftrace_filter; | echo function > current_tracer; | modprobe <module-name> Since FTRACE_ADDR/FTRACE_REGS_ADDR is only defined when CONFIG_DYNAMIC_ FTRACE is selected, we wrap their usage in module_init_ftrace_plt() with ifdeffery rather than using IS_ENABLED(). Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-12-14LoongArch/ftrace: Add dynamic function graph tracer supportQing Zhang
Once the function_graph tracer is enabled, a filtered function has the following call sequence: 1) ftracer_caller ==> on/off by ftrace_make_call/ftrace_make_nop 2) ftrace_graph_caller 3) ftrace_graph_call ==> on/off by ftrace_en/disable_ftrace_graph_caller 4) prepare_ftrace_return Considering the following DYNAMIC_FTRACE_WITH_REGS feature, it would be more extendable to have a ftrace_graph_caller function, instead of calling prepare_ftrace_return directly in ftrace_caller. Co-developed-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-12-14LoongArch/ftrace: Add dynamic function tracer supportQing Zhang
The compiler has inserted 2 NOPs before the regular function prologue. T series registers are available and safe because of LoongArch's psABI. At runtime, we can replace nop with bl to enable ftrace call and replace bl with nop to disable ftrace call. The bl instruction requires us to save the original RA value, so it saves RA at t0 here. Details are: | Compiled | Disabled | Enabled | +------------+------------------------+------------------------+ | nop | move t0, ra | move t0, ra | | nop | nop | bl ftrace_caller | | func_body | func_body | func_body | The RA value will be recovered by ftrace_regs_entry, and restored into RA before returning to the regular function prologue. When a function is not being traced, the "move t0, ra" is not harmful. 1) ftrace_make_call, ftrace_make_nop (in kernel/ftrace.c) The two functions turn each recorded call site of filtered functions into a call to ftrace_caller or nops. 2) ftracce_update_ftrace_func (in kernel/ftrace.c) turns the nops at ftrace_call into a call to a generic entry for function tracers. 3) ftrace_caller (in kernel/mcount_dyn.S) The entry where each _mcount call sites calls to once they are filtered to be traced. Co-developed-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-06-03LoongArch: Add ELF and module supportHuacai Chen
Add ELF-related definition and module relocation code for basic LoongArch support. Cc: Jessica Yu <jeyu@kernel.org> Reviewed-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>