[PATCH] [AArch64] support -mfentry feature for arm64
From: Jiangjiji
* gcc/config/aarch64/aarch64.opt: Add a new option.
* gcc/config/aarch64/aarch64.c: Add some new functions and Macros.
* gcc/config/aarch64/aarch64.h: Modify PROFILE_HOOK and FUNCTION_PROFILER.
Signed-off-by: Jiangjiji
Signed-off-by: Li Bin
---
gcc/config/aarch64/aarch64.c | 23 +++
gcc/config/aarch64/aarch64.h | 13 -
gcc/config/aarch64/aarch64.opt |4
3 files changed, 35 insertions(+), 5 deletions(-)
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 752df4e..c70b161 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -440,6 +440,17 @@ aarch64_is_long_call_p (rtx sym)
return aarch64_decl_is_long_call_p (SYMBOL_REF_DECL (sym));
}
+void
+aarch64_function_profiler (FILE *file, int labelno ATTRIBUTE_UNUSED)
+{
+ if (flag_fentry)
+ {
+ fprintf (file, "\tmov\tx9, x30\n");
+ fprintf (file, "\tbl\t__fentry__\n");
+ fprintf (file, "\tmov\tx30, x9\n");
+ }
+}
+
/* Return true if the offsets to a zero/sign-extract operation
represent an expression that matches an extend operation. The
operands represent the paramters from
@@ -7414,6 +7425,15 @@ aarch64_emit_unlikely_jump (rtx insn)
add_int_reg_note (insn, REG_BR_PROB, very_unlikely);
}
+/* Return true, if profiling code should be emitted before
+ * prologue. Otherwise it returns false.
+ * Note: For x86 with "hotfix" it is sorried. */
+static bool
+aarch64_profile_before_prologue (void)
+{
+ return flag_fentry != 0;
+}
+
/* Expand a compare and swap pattern. */
void
@@ -8454,6 +8474,9 @@ aarch64_cannot_change_mode_class (enum machine_mode from,
#undef TARGET_ASM_ALIGNED_SI_OP
#define TARGET_ASM_ALIGNED_SI_OP "\t.word\t"
+#undef TARGET_PROFILE_BEFORE_PROLOGUE
+#define TARGET_PROFILE_BEFORE_PROLOGUE aarch64_profile_before_prologue
+
#undef TARGET_ASM_CAN_OUTPUT_MI_THUNK
#define TARGET_ASM_CAN_OUTPUT_MI_THUNK \
hook_bool_const_tree_hwi_hwi_const_tree_true
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index 77b2bb9..65e34fc 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -804,13 +804,16 @@ do {
\
#define PROFILE_HOOK(LABEL)\
{\
rtx fun, lr; \
-lr = get_hard_reg_initial_val (Pmode, LR_REGNUM); \
-fun = gen_rtx_SYMBOL_REF (Pmode, MCOUNT_NAME); \
-emit_library_call (fun, LCT_NORMAL, VOIDmode, 1, lr, Pmode); \
+ if (!flag_fentry)
+ {
+ lr = get_hard_reg_initial_val (Pmode, LR_REGNUM);
\
+ fun = gen_rtx_SYMBOL_REF (Pmode, MCOUNT_NAME);
\
+ emit_library_call (fun, LCT_NORMAL, VOIDmode, 1, lr, Pmode);
\
+ }
}
-/* All the work done in PROFILE_HOOK, but still required. */
-#define FUNCTION_PROFILER(STREAM, LABELNO) do { } while (0)
+#define FUNCTION_PROFILER(STREAM, LABELNO)
+ aarch64_function_profiler(STREAM, LABELNO)
/* For some reason, the Linux headers think they know how to define
these macros. They don't!!! */
diff --git a/gcc/config/aarch64/aarch64.opt b/gcc/config/aarch64/aarch64.opt
index 266d873..9e4b408 100644
--- a/gcc/config/aarch64/aarch64.opt
+++ b/gcc/config/aarch64/aarch64.opt
@@ -124,3 +124,7 @@ Enum(aarch64_abi) String(ilp32) Value(AARCH64_ABI_ILP32)
EnumValue
Enum(aarch64_abi) String(lp64) Value(AARCH64_ABI_LP64)
+
+mfentry
+Target Report Var(flag_fentry) Init(0)
+Emit profiling counter call at function entry immediately after prologue.
--
1.7.1
[PATCH] [AArch64] support -mfentry feature for arm64
From: Jiangjiji
* gcc/config/aarch64/aarch64.opt: Add a new option.
* gcc/config/aarch64/aarch64.c: Add some new functions and Macros.
* gcc/config/aarch64/aarch64.h: Modify PROFILE_HOOK and FUNCTION_PROFILER.
Signed-off-by: Jiangjiji
Signed-off-by: Li Bin
---
gcc/config/aarch64/aarch64.c | 23 +++
gcc/config/aarch64/aarch64.h | 13 -
gcc/config/aarch64/aarch64.opt |4
3 files changed, 35 insertions(+), 5 deletions(-)
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 752df4e..c70b161 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -440,6 +440,17 @@ aarch64_is_long_call_p (rtx sym)
return aarch64_decl_is_long_call_p (SYMBOL_REF_DECL (sym));
}
+void
+aarch64_function_profiler (FILE *file, int labelno ATTRIBUTE_UNUSED)
+{
+ if (flag_fentry)
+ {
+ fprintf (file, "\tmov\tx9, x30\n");
+ fprintf (file, "\tbl\t__fentry__\n");
+ fprintf (file, "\tmov\tx30, x9\n");
+ }
+}
+
/* Return true if the offsets to a zero/sign-extract operation
represent an expression that matches an extend operation. The
operands represent the paramters from
@@ -7414,6 +7425,15 @@ aarch64_emit_unlikely_jump (rtx insn)
add_int_reg_note (insn, REG_BR_PROB, very_unlikely);
}
+/* Return true, if profiling code should be emitted before
+ * prologue. Otherwise it returns false.
+ * Note: For x86 with "hotfix" it is sorried. */
+static bool
+aarch64_profile_before_prologue (void)
+{
+ return flag_fentry != 0;
+}
+
/* Expand a compare and swap pattern. */
void
@@ -8454,6 +8474,9 @@ aarch64_cannot_change_mode_class (enum machine_mode from,
#undef TARGET_ASM_ALIGNED_SI_OP
#define TARGET_ASM_ALIGNED_SI_OP "\t.word\t"
+#undef TARGET_PROFILE_BEFORE_PROLOGUE
+#define TARGET_PROFILE_BEFORE_PROLOGUE aarch64_profile_before_prologue
+
#undef TARGET_ASM_CAN_OUTPUT_MI_THUNK
#define TARGET_ASM_CAN_OUTPUT_MI_THUNK \
hook_bool_const_tree_hwi_hwi_const_tree_true
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index 77b2bb9..65e34fc 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -804,13 +804,16 @@ do {
\
#define PROFILE_HOOK(LABEL)\
{\
rtx fun, lr; \
-lr = get_hard_reg_initial_val (Pmode, LR_REGNUM); \
-fun = gen_rtx_SYMBOL_REF (Pmode, MCOUNT_NAME); \
-emit_library_call (fun, LCT_NORMAL, VOIDmode, 1, lr, Pmode); \
+ if (!flag_fentry)
+ {
+ lr = get_hard_reg_initial_val (Pmode, LR_REGNUM);
\
+ fun = gen_rtx_SYMBOL_REF (Pmode, MCOUNT_NAME);
\
+ emit_library_call (fun, LCT_NORMAL, VOIDmode, 1, lr, Pmode);
\
+ }
}
-/* All the work done in PROFILE_HOOK, but still required. */
-#define FUNCTION_PROFILER(STREAM, LABELNO) do { } while (0)
+#define FUNCTION_PROFILER(STREAM, LABELNO)
+ aarch64_function_profiler(STREAM, LABELNO)
/* For some reason, the Linux headers think they know how to define
these macros. They don't!!! */
diff --git a/gcc/config/aarch64/aarch64.opt b/gcc/config/aarch64/aarch64.opt
index 266d873..9e4b408 100644
--- a/gcc/config/aarch64/aarch64.opt
+++ b/gcc/config/aarch64/aarch64.opt
@@ -124,3 +124,7 @@ Enum(aarch64_abi) String(ilp32) Value(AARCH64_ABI_ILP32)
EnumValue
Enum(aarch64_abi) String(lp64) Value(AARCH64_ABI_LP64)
+
+mfentry
+Target Report Var(flag_fentry) Init(0)
+Emit profiling counter call at function entry immediately after prologue.
--
1.7.1
[PATCH] [AArch64] support -mfentry feature for arm64
As ARM64 is entering enterprise world, machines can not be stopped for some critical enterprise production environment, that is, live patch as one of the RAS features is increasing more important for ARM64 arch now. Now, the mainstream live patch implementation which has been merged in Linux kernel (x86/s390) is based on the 'ftrace with regs' feature, and this feature needs the help of gcc. This patch proposes a generic solution for arm64 gcc which called mfentry, following the example of x86, mips, s390, etc. and on these archs, this feature has been used to implement the ftrace feature 'ftrace with regs' to support live patch. By now, there is an another solution from linaro [1], which proposes to implement a new option -fprolog-pad=N that generate a pad of N nops at the beginning of each function. This solution is a arch-independent way for gcc, but there may be some limitations which have not been recognized for Linux kernel to adapt to this solution besides the discussion on [2], typically for powerpc archs. Furthermore I think there are no good reasons to promote the other archs (such as x86) which have implemented the feature 'ftrace with regs' to replace the current method with the new option, which may bring heavily target-dependent code adaption, as a result it becomes a arm64 dedicated solution, leaving kernel with two different forms of implementation. [1] https://gcc.gnu.org/ml/gcc/2015-10/msg00090.html [2] http://lists.infradead.org/pipermail/linux-arm-kernel/2016-January/401854.html Jiangjiji (1): [AArch64] support -mfentry feature for arm64 gcc/config/aarch64/aarch64.c | 23 +++ gcc/config/aarch64/aarch64.h | 13 - gcc/config/aarch64/aarch64.opt |4 3 files changed, 35 insertions(+), 5 deletions(-)
