[PATCH 3/3] arm64: entry-ftrace.S: avoid open-coded {adr,ldr}_l
Mark Rutland
mark.rutland at arm.com
Tue Jan 17 08:10:58 PST 2017
Some places in the kernel open-code sequences using ADRP for a symbol
another instruction using a :lo12: relocation for that same symbol.
These sequences are easy to get wrong, and more painful to read than is
necessary. For these reasons, it is preferable to use the
{adr,ldr,str}_l macros for these cases.
This patch makes use of these in entry-ftrace.S, removing open-coded
sequences using adrp. This results in a minor code change, since a
temporary register is not used when generating the address for some
symbols, but this is fine, as the value of the temporary register is not
used elsewhere.
Signed-off-by: Mark Rutland <mark.rutland at arm.com>
Cc: AKASHI Takahiro <takahiro.akashi at linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel at linaro.org>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Will Deacon <will.deacon at arm.com>
---
arch/arm64/kernel/entry-ftrace.S | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/arch/arm64/kernel/entry-ftrace.S b/arch/arm64/kernel/entry-ftrace.S
index aef02d2..8f1905b 100644
--- a/arch/arm64/kernel/entry-ftrace.S
+++ b/arch/arm64/kernel/entry-ftrace.S
@@ -98,8 +98,7 @@
ENTRY(_mcount)
mcount_enter
- adrp x0, ftrace_trace_function
- ldr x2, [x0, #:lo12:ftrace_trace_function]
+ ldr_l x2, ftrace_trace_function
adr x0, ftrace_stub
cmp x0, x2 // if (ftrace_trace_function
b.eq skip_ftrace_call // != ftrace_stub) {
@@ -115,15 +114,12 @@ skip_ftrace_call: // return;
mcount_exit // return;
// }
skip_ftrace_call:
- adrp x1, ftrace_graph_return
- ldr x2, [x1, #:lo12:ftrace_graph_return]
+ ldr_l x2, ftrace_graph_return
cmp x0, x2 // if ((ftrace_graph_return
b.ne ftrace_graph_caller // != ftrace_stub)
- adrp x1, ftrace_graph_entry // || (ftrace_graph_entry
- adrp x0, ftrace_graph_entry_stub // != ftrace_graph_entry_stub))
- ldr x2, [x1, #:lo12:ftrace_graph_entry]
- add x0, x0, #:lo12:ftrace_graph_entry_stub
+ ldr_l x2, ftrace_graph_entry // || (ftrace_graph_entry
+ adr_l x0, ftrace_graph_entry_stub // != ftrace_graph_entry_stub))
cmp x0, x2
b.ne ftrace_graph_caller // ftrace_graph_caller();
--
1.9.1
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