kernel.git/arch/loongarch/kernel/inst.c, branch linux-6.10.y

LoongArch: Add larch_insn_gen_break() to generate break insns

2023-06-29T12:58:44Z

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 Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen

LoongArch: Check for AMO instructions in insns_not_supported()

2023-06-29T12:58:44Z

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 Reported-by: Hengqi Chen Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen

LoongArch: Move three functions from kprobes.c to inst.c

2023-06-29T12:58:44Z

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 Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen

LoongArch: Add guard for the larch_insn_gen_xxx functions

2023-06-29T12:58:42Z

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 Signed-off-by: Huacai Chen

LoongArch: Simulate branch and PC* instructions

2023-02-25T14:12:17Z

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 Co-developed-by: Jinyang He Signed-off-by: Jinyang He Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen

LoongArch: Simplify larch_insn_gen_xxx implementation

2023-01-17T03:42:16Z

Simplify larch_insn_gen_xxx implementation by reusing emit_xxx. Signed-off-by: Youling Tang Signed-off-by: Huacai Chen

LoongArch: modules/ftrace: Initialize PLT at load time

2022-12-14T00:41:54Z

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:" > set_ftrace_filter; | echo function > current_tracer; | modprobe 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 Signed-off-by: Huacai Chen

LoongArch/ftrace: Add dynamic function graph tracer support

2022-12-14T00:41:53Z

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 Signed-off-by: Jinyang He Signed-off-by: Qing Zhang Signed-off-by: Huacai Chen

LoongArch/ftrace: Add dynamic function tracer support

2022-12-14T00:41:53Z

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 Signed-off-by: Jinyang He Signed-off-by: Qing Zhang Signed-off-by: Huacai Chen

LoongArch: Add ELF and module support

2022-06-03T12:09:28Z

Add ELF-related definition and module relocation code for basic LoongArch support. Cc: Jessica Yu Reviewed-by: WANG Xuerui Reviewed-by: Luis Chamberlain Reviewed-by: Jiaxun Yang Signed-off-by: Huacai Chen