[RFC PATCH v3 17/22] arm64: Add kernel and module support for ORC

From: madvenka
Date: Thu Feb 02 2023 - 02:43:42 EST


From: "Madhavan T. Venkataraman" <madvenka@xxxxxxxxxxxxxxxxxxx>

Call orc_lookup_init() from setup_arch() to perform ORC lookup
initialization for vmlinux.

Call orc_lookup_module_init() in module load to perform ORC lookup
initialization for modules.

Signed-off-by: Madhavan T. Venkataraman <madvenka@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/kernel/module.c | 13 ++++++++++++-
arch/arm64/kernel/setup.c | 2 ++
2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index 76b41e4ca9fa..71264a181f61 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -19,6 +19,7 @@
#include <asm/alternative.h>
#include <asm/insn.h>
#include <asm/sections.h>
+#include <asm-generic/orc_lookup.h>

void *module_alloc(unsigned long size)
{
@@ -509,10 +510,20 @@ int module_finalize(const Elf_Ehdr *hdr,
const Elf_Shdr *sechdrs,
struct module *me)
{
- const Elf_Shdr *s;
+ const Elf_Shdr *s, *orc, *orc_ip;
+
s = find_section(hdr, sechdrs, ".altinstructions");
if (s)
apply_alternatives_module((void *)s->sh_addr, s->sh_size);

+ orc = find_section(hdr, sechdrs, ".orc_unwind");
+ orc_ip = find_section(hdr, sechdrs, ".orc_unwind_ip");
+
+ if (orc && orc_ip) {
+ orc_lookup_module_init(me,
+ (void *)orc_ip->sh_addr, orc_ip->sh_size,
+ (void *)orc->sh_addr, orc->sh_size);
+ }
+
return module_init_ftrace_plt(hdr, sechdrs, me);
}
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index fea3223704b6..360304dcd8c2 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -51,6 +51,7 @@
#include <asm/efi.h>
#include <asm/xen/hypervisor.h>
#include <asm/mmu_context.h>
+#include <asm-generic/orc_lookup.h>

static int num_standard_resources;
static struct resource *standard_resources;
@@ -378,6 +379,7 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p)
"This indicates a broken bootloader or old kernel\n",
boot_args[1], boot_args[2], boot_args[3]);
}
+ orc_lookup_init();
}

static inline bool cpu_can_disable(unsigned int cpu)
--
2.25.1