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| author | Jisheng Zhang <jszhang@kernel.org> | 2023-09-12 15:20:15 +0800 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2023-11-05 14:15:14 -0800 |
| commit | 8f8c1ff879fab60f80f3a7aec3000f47e5b03ba9 (patch) | |
| tree | c44022bf9b87705a8a3cacd8a135d72ac400a38a /arch/riscv | |
| parent | 49cfbdc21faf5fffbdaa8fd31e1451a4432cfdaa (diff) | |
| download | linux-8f8c1ff879fab60f80f3a7aec3000f47e5b03ba9.tar.gz linux-8f8c1ff879fab60f80f3a7aec3000f47e5b03ba9.tar.bz2 linux-8f8c1ff879fab60f80f3a7aec3000f47e5b03ba9.zip | |
riscv: vdso.lds.S: remove hardcoded 0x800 .text start addr
I believe the hardcoded 0x800 and related comments come from the long
history VDSO_TEXT_OFFSET in x86 vdso code, but commit 5b9304933730
("x86 vDSO: generate vdso-syms.lds") and commit f6b46ebf904f ("x86
vDSO: new layout") removes the comment and hard coding for x86.
Similar as x86 and other arch, riscv doesn't need the rigid layout
using VDSO_TEXT_OFFSET since it "no longer matters to the kernel".
so we could remove the hard coding now, and removing it brings a
small vdso.so and aligns with other architectures.
Also, having enough separation between data and text is important for
I-cache, so similar as x86, move .note, .eh_frame_hdr, and .eh_frame
between .rodata and .text.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Link: https://lore.kernel.org/r/20230912072015.2424-4-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv')
| -rw-r--r-- | arch/riscv/kernel/vdso/vdso.lds.S | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/arch/riscv/kernel/vdso/vdso.lds.S b/arch/riscv/kernel/vdso/vdso.lds.S index 671aa21769bc..cbe2a179331d 100644 --- a/arch/riscv/kernel/vdso/vdso.lds.S +++ b/arch/riscv/kernel/vdso/vdso.lds.S @@ -23,12 +23,8 @@ SECTIONS .gnu.version_d : { *(.gnu.version_d) } .gnu.version_r : { *(.gnu.version_r) } - .note : { *(.note.*) } :text :note .dynamic : { *(.dynamic) } :text :dynamic - .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr - .eh_frame : { KEEP (*(.eh_frame)) } :text - .rodata : { *(.rodata .rodata.* .gnu.linkonce.r.*) *(.got.plt) *(.got) @@ -37,13 +33,16 @@ SECTIONS *(.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 + /* - * 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); |