Merge patch series "riscv: vdso.lds.S: some improvement"

Jisheng Zhang <jszhang@kernel.org> says:

This series renews one of my last year RFC patch[1], tries to improve
the vdso layout a bit.

patch1 removes useless symbols
patch2 merges .data section of vdso into .rodata because they are
readonly
patch3 is the real renew patch, it removes hardcoded 0x800 .text start
addr. But I rewrite the commit msg per Andrew's suggestions and move
move .note, .eh_frame_hdr, and .eh_frame between .rodata and .text to
keep the actual code well away from the non-instruction data.

* b4-shazam-merge:
  riscv: vdso.lds.S: remove hardcoded 0x800 .text start addr
  riscv: vdso.lds.S: merge .data section into .rodata section
  riscv: vdso.lds.S: drop __alt_start and __alt_end symbols

Link: https://lore.kernel.org/linux-riscv/20221123161805.1579-1-jszhang@kernel.org/ [1]
Link: https://lore.kernel.org/r/20230912072015.2424-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/kernel/vdso/vdso.lds.S

@@ -23,35 +23,31 @@ SECTIONS
 	.gnu.version_d	: { *(.gnu.version_d) }
 	.gnu.version_r	: { *(.gnu.version_r) }
 
-	.note		: { *(.note.*) }		:text	:note
 	.dynamic	: { *(.dynamic) }		:text	:dynamic
 
+	.rodata		: {
+		*(.rodata .rodata.* .gnu.linkonce.r.*)
+		*(.got.plt) *(.got)
+		*(.data .data.* .gnu.linkonce.d.*)
+		*(.dynbss)
+		*(.bss .bss.* .gnu.linkonce.b.*)
+	}
+
+	.note		: { *(.note.*) }		:text	:note
+
 	.eh_frame_hdr	: { *(.eh_frame_hdr) }		:text	:eh_frame_hdr
 	.eh_frame	: { KEEP (*(.eh_frame)) }	:text
 
-	.rodata		: { *(.rodata .rodata.* .gnu.linkonce.r.*) }
-
 	/*
-	 * This linker script is used both with -r and with -shared.
-	 * For the layouts to match, we need to skip more than enough
-	 * space for the dynamic symbol table, etc. If this amount is
-	 * insufficient, ld -shared will error; simply increase it here.
+	 * Text is well-separated from actual data: there's plenty of
+	 * stuff that isn't used at runtime in between.
 	 */
-	. = 0x800;
+	. = ALIGN(16);
 	.text		: { *(.text .text.*) }		:text
 
 	. = ALIGN(4);
 	.alternative : {
-		__alt_start = .;
 		*(.alternative)
-		__alt_end = .;
-	}
-
-	.data		: {
-		*(.got.plt) *(.got)
-		*(.data .data.* .gnu.linkonce.d.*)
-		*(.dynbss)
-		*(.bss .bss.* .gnu.linkonce.b.*)
 	}
 }