[PATCH v5 01/12] riscv: ftrace: Fix to pass correct ftrace_regs to ftrace_func_t functions
From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Date: 2023-09-24 13:37:21
Also in:
bpf, lkml
Subsystem:
risc-v architecture, the rest · Maintainers:
Paul Walmsley, Palmer Dabbelt, Albert Ou, Linus Torvalds
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Since ftrace_func_t requires to pass 'struct ftrace_regs *' as the 4th
argument even if FTRACE_OPS_FL_SAVE_REGS is not set, ftrace_caller must
pass 'struct ftrace_regs *', which is a partial pt_regs, on the stack
to the ftrace_func_t functions, so that the ftrace_func_t functions can
access some partial registers.
Fix to allocate 'struct ftrace_regs' (which has the same size of 'struct
pt_regs') on the stack and save partial (argument) registers on it
instead of reduced size custom data structure.
Fixes: afc76b8b8011 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead of MCOUNT")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
arch/riscv/kernel/mcount-dyn.S | 65 +++++++++++++++++-----------------------
1 file changed, 28 insertions(+), 37 deletions(-)
diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S
index 669b8697aa38..84963680eff4 100644
--- a/arch/riscv/kernel/mcount-dyn.S
+++ b/arch/riscv/kernel/mcount-dyn.S@@ -14,46 +14,37 @@ .text #define FENTRY_RA_OFFSET 8 -#define ABI_SIZE_ON_STACK 80 -#define ABI_A0 0 -#define ABI_A1 8 -#define ABI_A2 16 -#define ABI_A3 24 -#define ABI_A4 32 -#define ABI_A5 40 -#define ABI_A6 48 -#define ABI_A7 56 -#define ABI_T0 64 -#define ABI_RA 72 .macro SAVE_ABI - addi sp, sp, -ABI_SIZE_ON_STACK - - REG_S a0, ABI_A0(sp) - REG_S a1, ABI_A1(sp) - REG_S a2, ABI_A2(sp) - REG_S a3, ABI_A3(sp) - REG_S a4, ABI_A4(sp) - REG_S a5, ABI_A5(sp) - REG_S a6, ABI_A6(sp) - REG_S a7, ABI_A7(sp) - REG_S t0, ABI_T0(sp) - REG_S ra, ABI_RA(sp) + addi sp, sp, -PT_SIZE_ON_STACK + + /* Save t0 as epc for ftrace_regs_get_instruction_pointer() */ + REG_S t0, PT_EPC(sp) + REG_S a0, PT_A0(sp) + REG_S a1, PT_A1(sp) + REG_S a2, PT_A2(sp) + REG_S a3, PT_A3(sp) + REG_S a4, PT_A4(sp) + REG_S a5, PT_A5(sp) + REG_S a6, PT_A6(sp) + REG_S a7, PT_A7(sp) + REG_S t0, PT_T0(sp) + REG_S ra, PT_RA(sp) .endm .macro RESTORE_ABI - REG_L a0, ABI_A0(sp) - REG_L a1, ABI_A1(sp) - REG_L a2, ABI_A2(sp) - REG_L a3, ABI_A3(sp) - REG_L a4, ABI_A4(sp) - REG_L a5, ABI_A5(sp) - REG_L a6, ABI_A6(sp) - REG_L a7, ABI_A7(sp) - REG_L t0, ABI_T0(sp) - REG_L ra, ABI_RA(sp) - - addi sp, sp, ABI_SIZE_ON_STACK + REG_L a0, PT_A0(sp) + REG_L a1, PT_A1(sp) + REG_L a2, PT_A2(sp) + REG_L a3, PT_A3(sp) + REG_L a4, PT_A4(sp) + REG_L a5, PT_A5(sp) + REG_L a6, PT_A6(sp) + REG_L a7, PT_A7(sp) + REG_L t0, PT_T0(sp) + REG_L ra, PT_RA(sp) + + addi sp, sp, PT_SIZE_ON_STACK .endm #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
@@ -96,8 +87,8 @@ ftrace_call: call ftrace_stub #ifdef CONFIG_FUNCTION_GRAPH_TRACER - addi a0, sp, ABI_RA - REG_L a1, ABI_T0(sp) + addi a0, sp, PT_RA + REG_L a1, PT_T0(sp) addi a1, a1, -FENTRY_RA_OFFSET #ifdef HAVE_FUNCTION_GRAPH_FP_TEST mv a2, s0