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| author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-06-17 16:56:16 -0400 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2021-10-19 20:33:12 -0400 |
| commit | 34cdd18b8d245f3e901e5325313c27de727ab80d (patch) | |
| tree | 4ed5ee40076e2018161e568a980cd3885636b39c /kernel | |
| parent | affc659246293df42ba2d184c674cc959c05aa02 (diff) | |
| download | linux-34cdd18b8d245f3e901e5325313c27de727ab80d.tar.bz2 | |
tracing: Use linker magic instead of recasting ftrace_ops_list_func()
In an effort to enable -Wcast-function-type in the top-level Makefile to
support Control Flow Integrity builds, all function casts need to be
removed.
This means that ftrace_ops_list_func() can no longer be defined as
ftrace_ops_no_ops(). The reason for ftrace_ops_no_ops() is to use that when
an architecture calls ftrace_ops_list_func() with only two parameters
(called from assembly). And to make sure there's no C side-effects, those
archs call ftrace_ops_no_ops() which only has two parameters, as
ftrace_ops_list_func() has four parameters.
Instead of a typecast, use vmlinux.lds.h to define ftrace_ops_list_func() to
arch_ftrace_ops_list_func() that will define the proper set of parameters.
Link: https://lore.kernel.org/r/20200614070154.6039-1-oscar.carter@gmx.com
Link: https://lkml.kernel.org/r/20200617165616.52241bde@oasis.local.home
Link: https://lore.kernel.org/all/20211005053922.GA702049@embeddedor/
Requested-by: Oscar Carter <oscar.carter@gmx.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/ftrace.c | 23 |
1 files changed, 10 insertions, 13 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 2c3e9760df7f..8b5801881271 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -119,14 +119,9 @@ struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end; ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; struct ftrace_ops global_ops; -#if ARCH_SUPPORTS_FTRACE_OPS -static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct ftrace_regs *fregs); -#else -/* See comment below, where ftrace_ops_list_func is defined */ -static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); -#define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) -#endif +/* Defined by vmlinux.lds.h see the commment above arch_ftrace_ops_list_func for details */ +void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs); static inline void ftrace_ops_init(struct ftrace_ops *ops) { @@ -7032,21 +7027,23 @@ out: * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. * An architecture can pass partial regs with ftrace_ops and still * set the ARCH_SUPPORTS_FTRACE_OPS. + * + * In vmlinux.lds.h, ftrace_ops_list_func() is defined to be + * arch_ftrace_ops_list_func. */ #if ARCH_SUPPORTS_FTRACE_OPS -static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct ftrace_regs *fregs) +void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs) { __ftrace_ops_list_func(ip, parent_ip, NULL, fregs); } -NOKPROBE_SYMBOL(ftrace_ops_list_func); #else -static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) +void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip) { __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); } -NOKPROBE_SYMBOL(ftrace_ops_no_ops); #endif +NOKPROBE_SYMBOL(arch_ftrace_ops_list_func); /* * If there's only one function registered but it does not support |