[RFC PATCH 06/15] powerpc/ftrace: Consolidate ftrace support into fewer files
Naveen N Rao
naveen at kernel.org
Thu Jun 8 02:55:21 AEST 2023
ftrace_low.S has just the _mcount stub and return_to_handler(). Merge
this back into ftrace_mprofile.S and ftrace_64_pg.S to keep all ftrace
code together, and to allow those to evolve independently.
ftrace_mprofile.S is also not an entirely accurate name since this also
holds ppc32 code. This will be all the more incorrect once support for
-fpatchable-function-entry is added. Rename files here to more
accurately describe the code:
- ftrace_mprofile.S is renamed to ftrace_entry.S
- ftrace_pg.c is renamed to ftrace_64_pg.c
- ftrace_64_pg.S is rename to ftrace_64_pg_entry.S
Signed-off-by: Naveen N Rao <naveen at kernel.org>
---
arch/powerpc/kernel/trace/Makefile | 17 +++--
arch/powerpc/kernel/trace/ftrace_64_pg.S | 67 -------------------
.../trace/{ftrace_pg.c => ftrace_64_pg.c} | 0
.../{ftrace_low.S => ftrace_64_pg_entry.S} | 58 +++++++++++++++-
.../{ftrace_mprofile.S => ftrace_entry.S} | 65 ++++++++++++++++++
5 files changed, 130 insertions(+), 77 deletions(-)
delete mode 100644 arch/powerpc/kernel/trace/ftrace_64_pg.S
rename arch/powerpc/kernel/trace/{ftrace_pg.c => ftrace_64_pg.c} (100%)
rename arch/powerpc/kernel/trace/{ftrace_low.S => ftrace_64_pg_entry.S} (55%)
rename arch/powerpc/kernel/trace/{ftrace_mprofile.S => ftrace_entry.S} (83%)
diff --git a/arch/powerpc/kernel/trace/Makefile b/arch/powerpc/kernel/trace/Makefile
index 342a2d1ae86cd0..125f4ca588b98a 100644
--- a/arch/powerpc/kernel/trace/Makefile
+++ b/arch/powerpc/kernel/trace/Makefile
@@ -6,16 +6,15 @@
ifdef CONFIG_FUNCTION_TRACER
# do not trace tracer code
CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE)
-CFLAGS_REMOVE_ftrace_pg.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_ftrace_64_pg.o = $(CC_FLAGS_FTRACE)
endif
-obj32-$(CONFIG_FUNCTION_TRACER) += ftrace_mprofile.o ftrace.o
+obj32-$(CONFIG_FUNCTION_TRACER) += ftrace.o ftrace_entry.o
ifdef CONFIG_MPROFILE_KERNEL
-obj64-$(CONFIG_FUNCTION_TRACER) += ftrace_mprofile.o ftrace.o
+obj64-$(CONFIG_FUNCTION_TRACER) += ftrace.o ftrace_entry.o
else
-obj64-$(CONFIG_FUNCTION_TRACER) += ftrace_64_pg.o ftrace_pg.o
+obj64-$(CONFIG_FUNCTION_TRACER) += ftrace_64_pg.o ftrace_64_pg_entry.o
endif
-obj-$(CONFIG_FUNCTION_TRACER) += ftrace_low.o
obj-$(CONFIG_TRACING) += trace_clock.o
obj-$(CONFIG_PPC64) += $(obj64-y)
@@ -26,7 +25,7 @@ GCOV_PROFILE_ftrace.o := n
KCOV_INSTRUMENT_ftrace.o := n
KCSAN_SANITIZE_ftrace.o := n
UBSAN_SANITIZE_ftrace.o := n
-GCOV_PROFILE_ftrace_pg.o := n
-KCOV_INSTRUMENT_ftrace_pg.o := n
-KCSAN_SANITIZE_ftrace_pg.o := n
-UBSAN_SANITIZE_ftrace_pg.o := n
+GCOV_PROFILE_ftrace_64_pg.o := n
+KCOV_INSTRUMENT_ftrace_64_pg.o := n
+KCSAN_SANITIZE_ftrace_64_pg.o := n
+UBSAN_SANITIZE_ftrace_64_pg.o := n
diff --git a/arch/powerpc/kernel/trace/ftrace_64_pg.S b/arch/powerpc/kernel/trace/ftrace_64_pg.S
deleted file mode 100644
index 6708e24db0aba8..00000000000000
--- a/arch/powerpc/kernel/trace/ftrace_64_pg.S
+++ /dev/null
@@ -1,67 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
-/*
- * Split from ftrace_64.S
- */
-
-#include <linux/magic.h>
-#include <asm/ppc_asm.h>
-#include <asm/asm-offsets.h>
-#include <asm/ftrace.h>
-#include <asm/ppc-opcode.h>
-#include <asm/export.h>
-
-_GLOBAL_TOC(ftrace_caller)
- lbz r3, PACA_FTRACE_ENABLED(r13)
- cmpdi r3, 0
- beqlr
-
- /* Taken from output of objdump from lib64/glibc */
- mflr r3
- ld r11, 0(r1)
- stdu r1, -112(r1)
- std r3, 128(r1)
- ld r4, 16(r11)
- subi r3, r3, MCOUNT_INSN_SIZE
-.globl ftrace_call
-ftrace_call:
- bl ftrace_stub
- nop
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-.globl ftrace_graph_call
-ftrace_graph_call:
- b ftrace_graph_stub
-_GLOBAL(ftrace_graph_stub)
-#endif
- ld r0, 128(r1)
- mtlr r0
- addi r1, r1, 112
-
-_GLOBAL(ftrace_stub)
- blr
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-_GLOBAL(ftrace_graph_caller)
- addi r5, r1, 112
- /* load r4 with local address */
- ld r4, 128(r1)
- subi r4, r4, MCOUNT_INSN_SIZE
-
- /* Grab the LR out of the caller stack frame */
- ld r11, 112(r1)
- ld r3, 16(r11)
-
- bl prepare_ftrace_return
- nop
-
- /*
- * prepare_ftrace_return gives us the address we divert to.
- * Change the LR in the callers stack frame to this.
- */
- ld r11, 112(r1)
- std r3, 16(r11)
-
- ld r0, 128(r1)
- mtlr r0
- addi r1, r1, 112
- blr
-#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/arch/powerpc/kernel/trace/ftrace_pg.c b/arch/powerpc/kernel/trace/ftrace_64_pg.c
similarity index 100%
rename from arch/powerpc/kernel/trace/ftrace_pg.c
rename to arch/powerpc/kernel/trace/ftrace_64_pg.c
diff --git a/arch/powerpc/kernel/trace/ftrace_low.S b/arch/powerpc/kernel/trace/ftrace_64_pg_entry.S
similarity index 55%
rename from arch/powerpc/kernel/trace/ftrace_low.S
rename to arch/powerpc/kernel/trace/ftrace_64_pg_entry.S
index 2fc7dd0a5ae968..81dbaf70b1513a 100644
--- a/arch/powerpc/kernel/trace/ftrace_low.S
+++ b/arch/powerpc/kernel/trace/ftrace_64_pg_entry.S
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
- * Split from entry_64.S
+ * Split from ftrace_64.S
*/
#include <linux/magic.h>
@@ -10,6 +10,62 @@
#include <asm/ppc-opcode.h>
#include <asm/export.h>
+_GLOBAL_TOC(ftrace_caller)
+ lbz r3, PACA_FTRACE_ENABLED(r13)
+ cmpdi r3, 0
+ beqlr
+
+ /* Taken from output of objdump from lib64/glibc */
+ mflr r3
+ ld r11, 0(r1)
+ stdu r1, -112(r1)
+ std r3, 128(r1)
+ ld r4, 16(r11)
+ subi r3, r3, MCOUNT_INSN_SIZE
+.globl ftrace_call
+ftrace_call:
+ bl ftrace_stub
+ nop
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+.globl ftrace_graph_call
+ftrace_graph_call:
+ b ftrace_graph_stub
+_GLOBAL(ftrace_graph_stub)
+#endif
+ ld r0, 128(r1)
+ mtlr r0
+ addi r1, r1, 112
+
+_GLOBAL(ftrace_stub)
+ blr
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+_GLOBAL(ftrace_graph_caller)
+ addi r5, r1, 112
+ /* load r4 with local address */
+ ld r4, 128(r1)
+ subi r4, r4, MCOUNT_INSN_SIZE
+
+ /* Grab the LR out of the caller stack frame */
+ ld r11, 112(r1)
+ ld r3, 16(r11)
+
+ bl prepare_ftrace_return
+ nop
+
+ /*
+ * prepare_ftrace_return gives us the address we divert to.
+ * Change the LR in the callers stack frame to this.
+ */
+ ld r11, 112(r1)
+ std r3, 16(r11)
+
+ ld r0, 128(r1)
+ mtlr r0
+ addi r1, r1, 112
+ blr
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
.pushsection ".tramp.ftrace.text","aw", at progbits;
.globl ftrace_tramp_text
ftrace_tramp_text:
diff --git a/arch/powerpc/kernel/trace/ftrace_mprofile.S b/arch/powerpc/kernel/trace/ftrace_entry.S
similarity index 83%
rename from arch/powerpc/kernel/trace/ftrace_mprofile.S
rename to arch/powerpc/kernel/trace/ftrace_entry.S
index ffb1db38684998..e8339706e735b1 100644
--- a/arch/powerpc/kernel/trace/ftrace_mprofile.S
+++ b/arch/powerpc/kernel/trace/ftrace_entry.S
@@ -249,3 +249,68 @@ livepatch_handler:
/* Return to original caller of live patched function */
blr
#endif /* CONFIG_LIVEPATCH */
+
+_GLOBAL(mcount)
+_GLOBAL(_mcount)
+EXPORT_SYMBOL(_mcount)
+ mflr r12
+ mtctr r12
+ mtlr r0
+ bctr
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+_GLOBAL(return_to_handler)
+ /* need to save return values */
+#ifdef CONFIG_PPC64
+ std r4, -32(r1)
+ std r3, -24(r1)
+ /* save TOC */
+ std r2, -16(r1)
+ std r31, -8(r1)
+ mr r31, r1
+ stdu r1, -112(r1)
+
+ /*
+ * We might be called from a module.
+ * Switch to our TOC to run inside the core kernel.
+ */
+ LOAD_PACA_TOC()
+#else
+ stwu r1, -16(r1)
+ stw r3, 8(r1)
+ stw r4, 12(r1)
+#endif
+
+ bl ftrace_return_to_handler
+ nop
+
+ /* return value has real return address */
+ mtlr r3
+
+#ifdef CONFIG_PPC64
+ ld r1, 0(r1)
+ ld r4, -32(r1)
+ ld r3, -24(r1)
+ ld r2, -16(r1)
+ ld r31, -8(r1)
+#else
+ lwz r3, 8(r1)
+ lwz r4, 12(r1)
+ addi r1, r1, 16
+#endif
+
+ /* Jump back to real return address */
+ blr
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+.pushsection ".tramp.ftrace.text","aw", at progbits;
+.globl ftrace_tramp_text
+ftrace_tramp_text:
+ .space 32
+.popsection
+
+.pushsection ".tramp.ftrace.init","aw", at progbits;
+.globl ftrace_tramp_init
+ftrace_tramp_init:
+ .space 32
+.popsection
--
2.40.1
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