Recordmcount utility under scripts is run, after compiling each object,
to find out all the locations of calling _mcount() and put them into
specific seciton named __mcount_loc.
Then linker collects all such information into a table in the kernel image
(between __start_mcount_loc and __stop_mcount_loc) for later use by ftrace.
This patch adds loongarch specific definitions to identify such locations.
On loongarch, only C version is used to build the kernel now that
CONFIG_HAVE_C_RECORDMCOUNT is on.
Signed-off-by: Qing Zhang <zhangqing@xxxxxxxxxxx>
---
arch/loongarch/Kconfig | 2 ++
scripts/recordmcount.c | 23 +++++++++++++++++++++++
2 files changed, 25 insertions(+)
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 703a2c3a8e0d..4d13bac368ed 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -80,10 +80,12 @@ config LOONGARCH
select HAVE_ARCH_TRANSPARENT_HUGEPAGE
select HAVE_ASM_MODVERSIONS
select HAVE_CONTEXT_TRACKING_USER
+ select HAVE_C_RECORDMCOUNT
select HAVE_DEBUG_STACKOVERFLOW
select HAVE_DMA_CONTIGUOUS
select HAVE_EXIT_THREAD
select HAVE_FAST_GUP
+ select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER
select HAVE_GENERIC_VDSO
diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c
index cce12e1971d8..ae42f9c5dc42 100644
--- a/scripts/recordmcount.c
+++ b/scripts/recordmcount.c
@@ -38,6 +38,13 @@
#define R_AARCH64_ABS64 257
#endif
+#ifndef EM_LOONGARCH
+#define EM_LOONGARCH 258
+#define R_LARCH_64 2
+#define R_LARCH_MARK_LA 20
+#define R_LARCH_SOP_PUSH_PLT_PCREL 29
+#endif
+
#define R_ARM_PC24 1
#define R_ARM_THM_CALL 10
#define R_ARM_CALL 28
@@ -441,6 +448,17 @@ static int arm64_is_fake_mcount(Elf64_Rel const *rp)
return ELF64_R_TYPE(w8(rp->r_info)) != R_AARCH64_CALL26;
}
+static int LARCH64_is_fake_mcount(Elf64_Rel const *rp)
+{
+ switch (ELF64_R_TYPE(w(rp->r_info))) {
+ case R_LARCH_MARK_LA:
+ case R_LARCH_SOP_PUSH_PLT_PCREL:
+ return 0;
+ }
+
+ return 1;
+}
+
/* 64-bit EM_MIPS has weird ELF64_Rela.r_info.
* http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf
* We interpret Table 29 Relocation Operation (Elf64_Rel, Elf64_Rela) [p.40]
@@ -558,6 +576,7 @@ static int do_file(char const *const fname)
break;
case EM_IA_64: reltype = R_IA64_IMM64; break;
case EM_MIPS: /* reltype: e_class */ break;
+ case EM_LOONGARCH: /* reltype: e_class */ break;
case EM_PPC: reltype = R_PPC_ADDR32; break;
case EM_PPC64: reltype = R_PPC64_ADDR64; break;
case EM_S390: /* reltype: e_class */ break;
@@ -610,6 +629,10 @@ static int do_file(char const *const fname)
Elf64_r_info = MIPS64_r_info;
is_fake_mcount64 = MIPS64_is_fake_mcount;
}
+ if (w2(ghdr->e_machine) == EM_LOONGARCH) {
+ reltype = R_LARCH_64;
+ is_fake_mcount64 = LARCH64_is_fake_mcount;
+ }
if (do64(ghdr, fname, reltype) < 0)
goto out;
break;
--
2.36.1
