[ Upstream commit 0cff8bff7af886af0923d5c91776cd51603e531f ]
The compiler uses the PIC-relative method to access static variables
instead of GOT when the code model is PIC. Therefore, the limitation of
the access range from the instruction to the symbol address is +-2GB.
Under this circumstance, the kernel cannot load a kernel module if this
module has static per-CPU symbols declared by DEFINE_PER_CPU(). The reason
is that kernel relocates the .data..percpu section of the kernel module to
the end of kernel's .data..percpu. Hence, the distance between the per-CPU
symbols and the instruction will exceed the 2GB limits. To solve this
problem, the kernel should place the loaded module in the memory area
[&_end-2G, VMALLOC_END].
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Suggested-by: Alexandre Ghiti <alex@ghiti.fr>
Suggested-by: Anup Patel <anup@brainfault.org>
Tested-by: Alexandre Ghiti <alex@ghiti.fr>
Tested-by: Carlos de Paula <me@carlosedp.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ef3a61406618291c46da168ff91acaa28d85944c ]
Fixes:
arch/riscv/kernel/module.c: In function 'apply_r_riscv_32_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:23:27: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_pcrel_hi20_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:104:23: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_hi20_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:146:23: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_got_hi20_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:190:60: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_call_plt_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:214:24: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_call_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:236:23: note: format string is defined here
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
These patches for building 32-bit RISC-V kernel.
- Fix the compile errors and warnings on RV32I.
- Fix some incompatible problem on RV32I.
- Add format.h for compatible of print format.
The fixed width integer types format for Elf_Addr will move to
generic header by another patch. For now, there are some warning
about unexpected argument of type on RV32I.
Change in v1:
- Fix some error in v1
- Remove implementation of fixed width integer types format for Elf_Addr.
The R_RISCV_ADD32/R_RISCV_SUB32 relocations should add/subtract the
address of the symbol (without overflow check), not its contents.
Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
With CONFIG_MODVERSIONS=y the R_RISCV_32 relocation is used by the
__kcrctab section.
Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Just fail on align type. Kernel modules loader didn't do relax
like linker, it is difficult to remove or migrate the code,
but the remnant nop instructions harm the performaace of module.
We expect the building module with the no-relax option.
Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
HI20 and LO12_I/LO12_S relocate the absolute address, the range of
offset must in 32-bit.
Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
For CALL_PLT, emit the plt entry only when offset is more than 32-bit.
For PCREL_LO12, it uses the location of corresponding HI20 to
get the address of external symbol. It should check the HI20 type
is the PCREL_HI20 or GOT_HI20, because sometime the location will
have two or more relocation types.
For example:
0: 00000797 auipc a5,0x0
0: R_RISCV_ALIGN *ABS*
0: R_RISCV_GOT_HI20 SYMBOL
4: 0007b783 ld a5,0(a5) # 0 <SYMBOL>
4: R_RISCV_PCREL_LO12_I .L0
4: R_RISCV_RELAX *ABS*
Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This patch contains code that is in some way visible to the user:
including via system calls, the VDSO, module loading and signal
handling. It also contains some generic code that is ABI visible.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
