summaryrefslogtreecommitdiff
path: root/arch/loongarch/include/asm/uaccess.h
AgeCommit message (Collapse)AuthorFilesLines
2023-02-25LoongArch: Use la.pcrel instead of la.abs when it's trivially possibleXi Ruoyao1-1/+0
Let's start to kill la.abs in preparation for the subsequent support of the PIE kernel. BTW, Re-tab the indention in arch/loongarch/kernel/entry.S for alignment. Signed-off-by: Xi Ruoyao <xry111@xry111.site> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-12-14LoongArch: extable: Add a dedicated uaccess handlerYouling Tang1-13/+4
Inspired by commit 2e77a62cb3a6("arm64: extable: add a dedicated uaccess handler"), do similar to LoongArch to add a dedicated uaccess exception handler to update registers in exception context and subsequently return back into the function which faulted, so we remove the need for fixups specialized to each faulting instruction. Add gpr-num.h here because we need to map the same GPR names to integer constants, so that we can use this to build meta-data for the exception fixups. The compiler treats gpr 0 as zero rather than $r0, so set it separately to .L__gpr_num_zero, otherwise the following assembly error will occurs: {standard input}: Assembler messages: {standard input}:1074: Error: invalid operands (*UND* and *ABS* sections) for `<<' {standard input}:1160: Error: invalid operands (*UND* and *ABS* sections) for `<<' make[1]: *** [scripts/Makefile.build:249: fs/fcntl.o] Error 1 Signed-off-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-12-14LoongArch: Switch to relative exception tablesYouling Tang1-1/+1
Similar to other architectures such as arm64, x86, riscv and so on, use offsets relative to the exception table entry values rather than their absolute addresses for both the exception location and the fixup. However, LoongArch label difference because it will actually produce two relocations, a pair of R_LARCH_ADD32 and R_LARCH_SUB32. Take simple code below for example: $ cat test_ex_table.S .section .text 1: nop .section __ex_table,"a" .balign 4 .long (1b - .) .previous $ loongarch64-unknown-linux-gnu-gcc -c test_ex_table.S $ loongarch64-unknown-linux-gnu-readelf -Wr test_ex_table.o Relocation section '.rela__ex_table' at offset 0x100 contains 2 entries: Offset Info Type Symbol's Value Symbol's Name + Addend 0000000000000000 0000000600000032 R_LARCH_ADD32 0000000000000000 .L1^B1 + 0 0000000000000000 0000000500000037 R_LARCH_SUB32 0000000000000000 L0^A + 0 The modpost will complain the R_LARCH_SUB32 relocation, so we need to patch modpost.c to skip this relocation for .rela__ex_table section. Signed-off-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-12-14LoongArch: Consolidate __ex_table constructionYouling Tang1-6/+3
Consolidate all the __ex_table constuction code with a _ASM_EXTABLE or _asm_extable helper. There should be no functional change as a result of this patch. Signed-off-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-08-12LoongArch: Requires __force attributes for any castsQing Zhang1-2/+2
This fix a warning when "make C=2": arch/loongarch/kernel/ptrace.c: note: in included file (through include/linux/uaccess.h, include/linux/sched/task.h, include/linux/sched/signal.h, include/linux/ptrace.h, include/linux/audit.h): ./arch/loongarch/include/asm/uaccess.h:232:32: warning: incorrect type in argument 2 (different address spaces) ./arch/loongarch/include/asm/uaccess.h:232:32: expected void const *from ./arch/loongarch/include/asm/uaccess.h:232:32: got void const [noderef] __user *from Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-07-29LoongArch: Use the "move" pseudo-instruction where applicableWANG Xuerui1-1/+1
Some of the assembly code in the LoongArch port likely originated from a time when the assembler did not support pseudo-instructions like "move" or "jr", so the desugared form was used and readability suffers (to a minor degree) as a result. As the upstream toolchain supports these pseudo-instructions from the beginning, migrate the existing few usages to them for better readability. Signed-off-by: WANG Xuerui <git@xen0n.name> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-07-29LoongArch: Use ABI names of registers where appropriateWANG Xuerui1-1/+1
Some of the assembly in the LoongArch port seem to come from a prehistoric time, when the assembler didn't even have support for the ABI names we all come to know and love, thus used raw register numbers which hampered readability. The usages are found with a regex match inside arch/loongarch, then manually adjusted for those non-definitions. Signed-off-by: WANG Xuerui <git@xen0n.name> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-06-03LoongArch: Add system call supportHuacai Chen1-0/+269
Add system call support and related uaccess.h for LoongArch. Q: Why keep _ARCH_WANT_SYS_CLONE definition while there is clone3: A: The latest glibc release has some basic support for clone3 but it is not complete. E.g., pthread_create() and spawni() have converted to use clone3 but fork() will still use clone. Moreover, some seccomp related applications can still not work perfectly with clone3. E.g., Chromium sandbox cannot work at all and there is no solution for it, which is more terrible than the fork() story [1]. [1] https://chromium-review.googlesource.com/c/chromium/src/+/2936184 Reviewed-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>