Skip to content

Commit

Permalink
x86/ftrace: Use text_poke()
Browse files Browse the repository at this point in the history
Move ftrace over to using the generic x86 text_poke functions; this
avoids having a second/different copy of that code around.

This also avoids ftrace violating the (new) W^X rule and avoids
fragmenting the kernel text page-tables, due to no longer having to
toggle them RW.

Tested-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191111132457.761255803@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
  • Loading branch information
Peter Zijlstra authored and Ingo Molnar committed Nov 27, 2019
1 parent 63f62ad commit 768ae44
Show file tree
Hide file tree
Showing 4 changed files with 134 additions and 558 deletions.
2 changes: 0 additions & 2 deletions arch/x86/include/asm/ftrace.h
Original file line number Diff line number Diff line change
Expand Up @@ -34,8 +34,6 @@ struct dyn_arch_ftrace {
/* No extra data needed for x86 */
};

int ftrace_int3_handler(struct pt_regs *regs);

#define FTRACE_GRAPH_TRAMP_ADDR FTRACE_GRAPH_ADDR

#endif /* CONFIG_DYNAMIC_FTRACE */
Expand Down
18 changes: 14 additions & 4 deletions arch/x86/kernel/alternative.c
Original file line number Diff line number Diff line change
Expand Up @@ -949,7 +949,7 @@ static struct bp_patching_desc {
int nr_entries;
} bp_patching;

static int patch_cmp(const void *key, const void *elt)
static int notrace patch_cmp(const void *key, const void *elt)
{
struct text_poke_loc *tp = (struct text_poke_loc *) elt;

Expand All @@ -961,7 +961,7 @@ static int patch_cmp(const void *key, const void *elt)
}
NOKPROBE_SYMBOL(patch_cmp);

int poke_int3_handler(struct pt_regs *regs)
int notrace poke_int3_handler(struct pt_regs *regs)
{
struct text_poke_loc *tp;
void *ip;
Expand Down Expand Up @@ -1209,10 +1209,15 @@ void text_poke_finish(void)
text_poke_flush(NULL);
}

void text_poke_queue(void *addr, const void *opcode, size_t len, const void *emulate)
void __ref text_poke_queue(void *addr, const void *opcode, size_t len, const void *emulate)
{
struct text_poke_loc *tp;

if (unlikely(system_state == SYSTEM_BOOTING)) {
text_poke_early(addr, opcode, len);
return;
}

text_poke_flush(addr);

tp = &tp_vec[tp_vec_nr++];
Expand All @@ -1230,10 +1235,15 @@ void text_poke_queue(void *addr, const void *opcode, size_t len, const void *emu
* dynamically allocated memory. This function should be used when it is
* not possible to allocate memory.
*/
void text_poke_bp(void *addr, const void *opcode, size_t len, const void *emulate)
void __ref text_poke_bp(void *addr, const void *opcode, size_t len, const void *emulate)
{
struct text_poke_loc tp;

if (unlikely(system_state == SYSTEM_BOOTING)) {
text_poke_early(addr, opcode, len);
return;
}

text_poke_loc_init(&tp, addr, opcode, len, emulate);
text_poke_bp_batch(&tp, 1);
}
Expand Down
Loading

0 comments on commit 768ae44

Please sign in to comment.