summaryrefslogtreecommitdiff
path: root/arch/riscv/kernel/alternative.c
diff options
context:
space:
mode:
authorJisheng Zhang <jszhang@kernel.org>2023-01-29 01:28:53 +0800
committerPalmer Dabbelt <palmer@rivosinc.com>2023-01-31 23:29:42 -0800
commitcabfd146b371462ed480a968f98eb0c2c80e3c8a (patch)
tree38df344a6023b4f31d3b03877eb0b550b7d0a820 /arch/riscv/kernel/alternative.c
parent8d23e94a443388e81c42ea7e476a5d79c1c795c9 (diff)
riscv: alternative: patch alternatives in the vDSO
Make it possible to use alternatives in the vDSO, so that better implementations can be used if possible. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20230128172856.3814-11-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/kernel/alternative.c')
-rw-r--r--arch/riscv/kernel/alternative.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c
index 3d4f1f32c7f6..fc341b69bf62 100644
--- a/arch/riscv/kernel/alternative.c
+++ b/arch/riscv/kernel/alternative.c
@@ -11,7 +11,9 @@
#include <linux/cpu.h>
#include <linux/uaccess.h>
#include <asm/alternative.h>
+#include <asm/module.h>
#include <asm/sections.h>
+#include <asm/vdso.h>
#include <asm/vendorid_list.h>
#include <asm/sbi.h>
#include <asm/csr.h>
@@ -160,6 +162,31 @@ static void __init_or_module _apply_alternatives(struct alt_entry *begin,
stage);
}
+#ifdef CONFIG_MMU
+static void __init apply_vdso_alternatives(void)
+{
+ const Elf_Ehdr *hdr;
+ const Elf_Shdr *shdr;
+ const Elf_Shdr *alt;
+ struct alt_entry *begin, *end;
+
+ hdr = (Elf_Ehdr *)vdso_start;
+ shdr = (void *)hdr + hdr->e_shoff;
+ alt = find_section(hdr, shdr, ".alternative");
+ if (!alt)
+ return;
+
+ begin = (void *)hdr + alt->sh_offset,
+ end = (void *)hdr + alt->sh_offset + alt->sh_size,
+
+ _apply_alternatives((struct alt_entry *)begin,
+ (struct alt_entry *)end,
+ RISCV_ALTERNATIVES_BOOT);
+}
+#else
+static void __init apply_vdso_alternatives(void) { }
+#endif
+
void __init apply_boot_alternatives(void)
{
/* If called on non-boot cpu things could go wrong */
@@ -168,6 +195,8 @@ void __init apply_boot_alternatives(void)
_apply_alternatives((struct alt_entry *)__alt_start,
(struct alt_entry *)__alt_end,
RISCV_ALTERNATIVES_BOOT);
+
+ apply_vdso_alternatives();
}
/*