From: Jisheng Zhang <jszhang3@mail.ustc.edu.cn> To: "Paul Walmsley" <paul.walmsley@sifive.com>, "Palmer Dabbelt" <palmer@dabbelt.com>, "Albert Ou" <aou@eecs.berkeley.edu>, "Björn Töpel" <bjorn@kernel.org>, "Alexei Starovoitov" <ast@kernel.org>, "Daniel Borkmann" <daniel@iogearbox.net>, "Andrii Nakryiko" <andrii@kernel.org>, "Martin KaFai Lau" <kafai@fb.com>, "Song Liu" <songliubraving@fb.com>, "Yonghong Song" <yhs@fb.com>, "John Fastabend" <john.fastabend@gmail.com>, "KP Singh" <kpsingh@kernel.org>, "Masahiro Yamada" <masahiroy@kernel.org>, "Michal Marek" <michal.lkml@markovi.net>, "Nick Desaulniers" <ndesaulniers@google.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com>, Tong Tiangen <tongtiangen@huawei.com>, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kbuild@vger.kernel.org Subject: [PATCH 07/12] riscv: lib: uaccess: fold fixups into body Date: Thu, 18 Nov 2021 19:25:14 +0800 [thread overview] Message-ID: <20211118192514.13d3e873@xhacker> (raw) In-Reply-To: <20211118192130.48b8f04c@xhacker> From: Jisheng Zhang <jszhang@kernel.org> uaccess functions such __asm_copy_to_user(), __arch_copy_from_user() and __clear_user() place their exception fixups in the `.fixup` section without any clear association with themselves. If we backtrace the fixup code, it will be symbolized as an offset from the nearest prior symbol. Similar as arm64 does, we must move fixups into the body of the functions themselves, after the usual fast-path returns. Inline assembly will be dealt with in subsequent patches. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> --- arch/riscv/lib/uaccess.S | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/arch/riscv/lib/uaccess.S b/arch/riscv/lib/uaccess.S index 55f80f84e23f..047f517ac780 100644 --- a/arch/riscv/lib/uaccess.S +++ b/arch/riscv/lib/uaccess.S @@ -173,6 +173,13 @@ ENTRY(__asm_copy_from_user) csrc CSR_STATUS, t6 li a0, 0 ret + + /* Exception fixup code */ +10: + /* Disable access to user memory */ + csrs CSR_STATUS, t6 + mv a0, t5 + ret ENDPROC(__asm_copy_to_user) ENDPROC(__asm_copy_from_user) EXPORT_SYMBOL(__asm_copy_to_user) @@ -218,19 +225,12 @@ ENTRY(__clear_user) addi a0, a0, 1 bltu a0, a3, 5b j 3b -ENDPROC(__clear_user) -EXPORT_SYMBOL(__clear_user) - .section .fixup,"ax" - .balign 4 - /* Fixup code for __copy_user(10) and __clear_user(11) */ -10: - /* Disable access to user memory */ - csrs CSR_STATUS, t6 - mv a0, t5 - ret + /* Exception fixup code */ 11: + /* Disable access to user memory */ csrs CSR_STATUS, t6 mv a0, a1 ret - .previous +ENDPROC(__clear_user) +EXPORT_SYMBOL(__clear_user) -- 2.33.0 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv
WARNING: multiple messages have this Message-ID (diff)
From: Jisheng Zhang <jszhang3@mail.ustc.edu.cn> To: "Paul Walmsley" <paul.walmsley@sifive.com>, "Palmer Dabbelt" <palmer@dabbelt.com>, "Albert Ou" <aou@eecs.berkeley.edu>, "Björn Töpel" <bjorn@kernel.org>, "Alexei Starovoitov" <ast@kernel.org>, "Daniel Borkmann" <daniel@iogearbox.net>, "Andrii Nakryiko" <andrii@kernel.org>, "Martin KaFai Lau" <kafai@fb.com>, "Song Liu" <songliubraving@fb.com>, "Yonghong Song" <yhs@fb.com>, "John Fastabend" <john.fastabend@gmail.com>, "KP Singh" <kpsingh@kernel.org>, "Masahiro Yamada" <masahiroy@kernel.org>, "Michal Marek" <michal.lkml@markovi.net>, "Nick Desaulniers" <ndesaulniers@google.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com>, Tong Tiangen <tongtiangen@huawei.com>, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kbuild@vger.kernel.org Subject: [PATCH 07/12] riscv: lib: uaccess: fold fixups into body Date: Thu, 18 Nov 2021 19:25:14 +0800 [thread overview] Message-ID: <20211118192514.13d3e873@xhacker> (raw) In-Reply-To: <20211118192130.48b8f04c@xhacker> From: Jisheng Zhang <jszhang@kernel.org> uaccess functions such __asm_copy_to_user(), __arch_copy_from_user() and __clear_user() place their exception fixups in the `.fixup` section without any clear association with themselves. If we backtrace the fixup code, it will be symbolized as an offset from the nearest prior symbol. Similar as arm64 does, we must move fixups into the body of the functions themselves, after the usual fast-path returns. Inline assembly will be dealt with in subsequent patches. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> --- arch/riscv/lib/uaccess.S | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/arch/riscv/lib/uaccess.S b/arch/riscv/lib/uaccess.S index 55f80f84e23f..047f517ac780 100644 --- a/arch/riscv/lib/uaccess.S +++ b/arch/riscv/lib/uaccess.S @@ -173,6 +173,13 @@ ENTRY(__asm_copy_from_user) csrc CSR_STATUS, t6 li a0, 0 ret + + /* Exception fixup code */ +10: + /* Disable access to user memory */ + csrs CSR_STATUS, t6 + mv a0, t5 + ret ENDPROC(__asm_copy_to_user) ENDPROC(__asm_copy_from_user) EXPORT_SYMBOL(__asm_copy_to_user) @@ -218,19 +225,12 @@ ENTRY(__clear_user) addi a0, a0, 1 bltu a0, a3, 5b j 3b -ENDPROC(__clear_user) -EXPORT_SYMBOL(__clear_user) - .section .fixup,"ax" - .balign 4 - /* Fixup code for __copy_user(10) and __clear_user(11) */ -10: - /* Disable access to user memory */ - csrs CSR_STATUS, t6 - mv a0, t5 - ret + /* Exception fixup code */ 11: + /* Disable access to user memory */ csrs CSR_STATUS, t6 mv a0, a1 ret - .previous +ENDPROC(__clear_user) +EXPORT_SYMBOL(__clear_user) -- 2.33.0
next prev parent reply other threads:[~2021-11-18 11:35 UTC|newest] Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-11-18 11:21 [PATCH v4 0/12] riscv: switch to relative extable and other improvements Jisheng Zhang 2021-11-18 11:21 ` Jisheng Zhang 2021-11-18 11:22 ` [PATCH 01/12] riscv: remove unused __cmpxchg_user() macro Jisheng Zhang 2021-11-18 11:22 ` Jisheng Zhang 2021-11-18 11:22 ` [PATCH 02/12] riscv: consolidate __ex_table construction Jisheng Zhang 2021-11-18 11:22 ` Jisheng Zhang 2021-11-18 11:22 ` [PATCH 03/12] riscv: switch to relative exception tables Jisheng Zhang 2021-11-18 11:22 ` Jisheng Zhang 2021-11-19 2:09 ` tongtiangen 2021-11-19 2:09 ` tongtiangen 2021-11-18 11:23 ` [PATCH 04/12] riscv: bpf: move rv_bpf_fixup_exception signature to extable.h Jisheng Zhang 2021-11-18 11:23 ` Jisheng Zhang 2021-11-18 11:24 ` [PATCH 05/12] riscv: extable: make fixup_exception() return bool Jisheng Zhang 2021-11-18 11:24 ` Jisheng Zhang 2021-11-18 11:24 ` [PATCH 06/12] riscv: extable: use `ex` for `exception_table_entry` Jisheng Zhang 2021-11-18 11:24 ` Jisheng Zhang 2021-11-18 11:25 ` Jisheng Zhang [this message] 2021-11-18 11:25 ` [PATCH 07/12] riscv: lib: uaccess: fold fixups into body Jisheng Zhang 2021-11-18 11:25 ` [PATCH 08/12] riscv: extable: consolidate definitions Jisheng Zhang 2021-11-18 11:25 ` Jisheng Zhang 2021-11-18 11:26 ` [PATCH 09/12] riscv: extable: add `type` and `data` fields Jisheng Zhang 2021-11-18 11:26 ` Jisheng Zhang 2021-11-18 11:42 ` Jisheng Zhang 2021-11-18 11:42 ` Jisheng Zhang 2021-11-18 15:21 ` Mark Rutland 2021-11-18 15:21 ` Mark Rutland 2022-01-06 3:21 ` Palmer Dabbelt 2022-01-06 3:21 ` Palmer Dabbelt 2022-01-06 10:23 ` Mark Rutland 2022-01-06 10:23 ` Mark Rutland 2021-11-19 2:35 ` tongtiangen 2021-11-19 2:35 ` tongtiangen 2021-11-18 11:26 ` [PATCH 10/12] riscv: add gpr-num.h Jisheng Zhang 2021-11-18 11:26 ` Jisheng Zhang 2021-11-18 11:26 ` [PATCH 11/12] riscv: extable: add a dedicated uaccess handler Jisheng Zhang 2021-11-18 11:26 ` Jisheng Zhang 2021-11-18 17:31 ` kernel test robot 2022-01-20 18:15 ` Mayuresh Chitale 2022-01-20 18:15 ` Mayuresh Chitale 2022-01-21 12:16 ` Jisheng Zhang 2022-01-21 12:16 ` Jisheng Zhang 2022-01-23 9:12 ` Jisheng Zhang 2022-01-23 9:12 ` Jisheng Zhang 2022-01-24 17:02 ` Mayuresh Chitale 2022-01-24 17:02 ` Mayuresh Chitale 2021-11-18 11:27 ` [PATCH 12/12] riscv: vmlinux.lds.S|vmlinux-xip.lds.S: remove `.fixup` section Jisheng Zhang 2021-11-18 11:27 ` Jisheng Zhang
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20211118192514.13d3e873@xhacker \ --to=jszhang3@mail.ustc.edu.cn \ --cc=andrii@kernel.org \ --cc=aou@eecs.berkeley.edu \ --cc=ast@kernel.org \ --cc=bjorn@kernel.org \ --cc=bpf@vger.kernel.org \ --cc=daniel@iogearbox.net \ --cc=john.fastabend@gmail.com \ --cc=kafai@fb.com \ --cc=kpsingh@kernel.org \ --cc=linux-kbuild@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-riscv@lists.infradead.org \ --cc=masahiroy@kernel.org \ --cc=michal.lkml@markovi.net \ --cc=ndesaulniers@google.com \ --cc=netdev@vger.kernel.org \ --cc=palmer@dabbelt.com \ --cc=paul.walmsley@sifive.com \ --cc=songliubraving@fb.com \ --cc=tongtiangen@huawei.com \ --cc=wangkefeng.wang@huawei.com \ --cc=yhs@fb.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.