Message ID | 20230811150604.1621784-1-alexghiti@rivosinc.com (mailing list archive) |
---|---|
State | Accepted |
Commit | 4b05b993900dd3eba0fc83ef5c5ddc7d65d786c6 |
Headers | show |
Series | [-fixes,v2] riscv: uaccess: Return the number of bytes effectively not copied | expand |
Context | Check | Description |
---|---|---|
conchuod/cover_letter | success | Single patches do not need cover letters |
conchuod/tree_selection | success | Guessed tree name to be fixes at HEAD 7e3811521dc3 |
conchuod/fixes_present | success | Fixes tag present in non-next series |
conchuod/maintainers_pattern | success | MAINTAINERS pattern errors before the patch: 4 and now 4 |
conchuod/verify_signedoff | success | Signed-off-by tag matches author and committer |
conchuod/kdoc | success | Errors and warnings before: 0 this patch: 0 |
conchuod/build_rv64_clang_allmodconfig | success | Errors and warnings before: 9 this patch: 9 |
conchuod/module_param | success | Was 0 now: 0 |
conchuod/build_rv64_gcc_allmodconfig | success | Errors and warnings before: 9 this patch: 9 |
conchuod/build_rv32_defconfig | success | Build OK |
conchuod/dtb_warn_rv64 | success | Errors and warnings before: 12 this patch: 12 |
conchuod/header_inline | success | No static functions without inline keyword in header files |
conchuod/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 29 lines checked |
conchuod/build_rv64_nommu_k210_defconfig | success | Build OK |
conchuod/verify_fixes | success | Fixes tag looks correct |
conchuod/build_rv64_nommu_virt_defconfig | success | Build OK |
Hello: This patch was applied to riscv/linux.git (fixes) by Palmer Dabbelt <palmer@rivosinc.com>: On Fri, 11 Aug 2023 17:06:04 +0200 you wrote: > It was reported that the riscv kernel hangs while executing the test > in [1]. > > Indeed, the test hangs when trying to write a buffer to a file. The > problem is that the riscv implementation of raw_copy_from_user() does not > return the correct number of bytes not written when an exception happens > and is fixed up, instead it always returns the initial size to copy, > even if some bytes were actually copied. > > [...] Here is the summary with links: - [-fixes,v2] riscv: uaccess: Return the number of bytes effectively not copied https://git.kernel.org/riscv/c/4b05b993900d You are awesome, thank you!
diff --git a/arch/riscv/lib/uaccess.S b/arch/riscv/lib/uaccess.S index ec486e5369d9..09b47ebacf2e 100644 --- a/arch/riscv/lib/uaccess.S +++ b/arch/riscv/lib/uaccess.S @@ -17,8 +17,11 @@ ENTRY(__asm_copy_from_user) li t6, SR_SUM csrs CSR_STATUS, t6 - /* Save for return value */ - mv t5, a2 + /* + * Save the terminal address which will be used to compute the number + * of bytes copied in case of a fixup exception. + */ + add t5, a0, a2 /* * Register allocation for code below: @@ -176,7 +179,7 @@ ENTRY(__asm_copy_from_user) 10: /* Disable access to user memory */ csrc CSR_STATUS, t6 - mv a0, t5 + sub a0, t5, a0 ret ENDPROC(__asm_copy_to_user) ENDPROC(__asm_copy_from_user) @@ -228,7 +231,7 @@ ENTRY(__clear_user) 11: /* Disable access to user memory */ csrc CSR_STATUS, t6 - mv a0, a1 + sub a0, a3, a0 ret ENDPROC(__clear_user) EXPORT_SYMBOL(__clear_user)