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arm64: ftrace: minimize ifdeffery 

Now that we no longer refer to mod->arch.ftrace_trampolines in the body
of ftrace_make_call(), we can use IS_ENABLED() rather than ifdeffery,
and make the code easier to follow. Likewise in ftrace_make_nop().

Let's do so.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
This commit is contained in:
Mark Rutland 2019-10-21 15:05:52 +01:00
parent 3b23e4991f
commit 7f08ae53a7
1 changed files with 8 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
arch/arm64/kernel/ftrace.c
View File

@ -62,18 +62,18 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
return ftrace_modify_code(pc, 0, new, false);
}
#ifdef CONFIG_ARM64_MODULE_PLTS
static struct plt_entry *get_ftrace_plt(struct module *mod, unsigned long addr)
{
#ifdef CONFIG_ARM64_MODULE_PLTS
struct plt_entry *plt = mod->arch.ftrace_trampolines;
if (addr == FTRACE_ADDR)
return &plt[FTRACE_PLT_IDX];
if (addr == FTRACE_REGS_ADDR && IS_ENABLED(CONFIG_FTRACE_WITH_REGS))
return &plt[FTRACE_REGS_PLT_IDX];
#endif
return NULL;
}
#endif
/*
* Turn on the call to ftrace_caller() in instrumented function
@ -85,10 +85,12 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
long offset = (long)pc - (long)addr;
if (offset < -SZ_128M || offset >= SZ_128M) {
#ifdef CONFIG_ARM64_MODULE_PLTS
struct module *mod;
struct plt_entry *plt;
if (!IS_ENABLED(CONFIG_ARM64_MODULE_PLTS))
return -EINVAL;
/*
* On kernels that support module PLTs, the offset between the
* branch instruction and its target may legally exceed the
@ -113,9 +115,6 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
}
addr = (unsigned long)plt;
#else /* CONFIG_ARM64_MODULE_PLTS */
return -EINVAL;
#endif /* CONFIG_ARM64_MODULE_PLTS */
}
old = aarch64_insn_gen_nop();
@ -185,9 +184,11 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
long offset = (long)pc - (long)addr;
if (offset < -SZ_128M || offset >= SZ_128M) {
#ifdef CONFIG_ARM64_MODULE_PLTS
u32 replaced;
if (!IS_ENABLED(CONFIG_ARM64_MODULE_PLTS))
return -EINVAL;
/*
* 'mod' is only set at module load time, but if we end up
* dealing with an out-of-range condition, we can assume it
@ -218,9 +219,6 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
return -EINVAL;
validate = false;
#else /* CONFIG_ARM64_MODULE_PLTS */
return -EINVAL;
#endif /* CONFIG_ARM64_MODULE_PLTS */
} else {
old = aarch64_insn_gen_branch_imm(pc, addr,
AARCH64_INSN_BRANCH_LINK);