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[54.170.241.106]) by smtp.gmail.com with ESMTPSA id h11-20020a5d548b000000b00317e77106dbsm22396112wrv.48.2023.08.24.06.31.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 24 Aug 2023 06:31:38 -0700 (PDT) From: Puranjay Mohan To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, pulehui@huawei.com, conor.dooley@microchip.com, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, kpsingh@kernel.org, bjorn@kernel.org, bpf@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: puranjay12@gmail.com Subject: [PATCH bpf-next v2 1/3] riscv: extend patch_text_nosync() for multiple pages Date: Thu, 24 Aug 2023 13:31:33 +0000 Message-Id: <20230824133135.1176709-2-puranjay12@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230824133135.1176709-1-puranjay12@gmail.com> References: <20230824133135.1176709-1-puranjay12@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-1.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FROM,RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net The patch_insn_write() function currently doesn't work for multiple pages of instructions, therefore patch_text_nosync() will fail with a page fault if called with lengths spanning multiple pages. This commit extends the patch_insn_write() function to support multiple pages by copying at max 2 pages at a time in a loop. This implementation is similar to text_poke_copy() function of x86. Signed-off-by: Puranjay Mohan Reviewed-by: Björn Töpel --- arch/riscv/kernel/patch.c | 39 ++++++++++++++++++++++++++++++++++----- 1 file changed, 34 insertions(+), 5 deletions(-) diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c index 575e71d6c8ae..465b2eebbc37 100644 --- a/arch/riscv/kernel/patch.c +++ b/arch/riscv/kernel/patch.c @@ -53,12 +53,18 @@ static void patch_unmap(int fixmap) } NOKPROBE_SYMBOL(patch_unmap); -static int patch_insn_write(void *addr, const void *insn, size_t len) +static int __patch_insn_write(void *addr, const void *insn, size_t len) { void *waddr = addr; bool across_pages = (((uintptr_t) addr & ~PAGE_MASK) + len) > PAGE_SIZE; int ret; + /* + * Only two pages can be mapped at a time for writing. + */ + if (len > 2 * PAGE_SIZE) + return -EINVAL; + /* * Before reaching here, it was expected to lock the text_mutex * already, so we don't need to give another lock here and could @@ -74,7 +80,7 @@ static int patch_insn_write(void *addr, const void *insn, size_t len) lockdep_assert_held(&text_mutex); if (across_pages) - patch_map(addr + len, FIX_TEXT_POKE1); + patch_map(addr + PAGE_SIZE, FIX_TEXT_POKE1); waddr = patch_map(addr, FIX_TEXT_POKE0); @@ -87,15 +93,38 @@ static int patch_insn_write(void *addr, const void *insn, size_t len) return ret; } -NOKPROBE_SYMBOL(patch_insn_write); +NOKPROBE_SYMBOL(__patch_insn_write); #else -static int patch_insn_write(void *addr, const void *insn, size_t len) +static int __patch_insn_write(void *addr, const void *insn, size_t len) { return copy_to_kernel_nofault(addr, insn, len); } -NOKPROBE_SYMBOL(patch_insn_write); +NOKPROBE_SYMBOL(__patch_insn_write); #endif /* CONFIG_MMU */ +static int patch_insn_write(void *addr, const void *insn, size_t len) +{ + size_t patched = 0; + size_t size; + int ret = 0; + + /* + * Copy the instructions to the destination address, two pages at a time + * because __patch_insn_write() can only handle len <= 2 * PAGE_SIZE. + */ + while (patched < len && !ret) { + size = min_t(size_t, + PAGE_SIZE * 2 - offset_in_page(addr + patched), + len - patched); + ret = __patch_insn_write(addr + patched, insn + patched, size); + + patched += size; + } + + return ret; +} +NOKPROBE_SYMBOL(patch_insn_write); + int patch_text_nosync(void *addr, const void *insns, size_t len) { u32 *tp = addr; From patchwork Thu Aug 24 13:31:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Puranjay Mohan X-Patchwork-Id: 13364144 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3A5A4CA6E for ; Thu, 24 Aug 2023 13:31:44 +0000 (UTC) Received: from mail-wr1-x434.google.com (mail-wr1-x434.google.com [IPv6:2a00:1450:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E07FBE78; Thu, 24 Aug 2023 06:31:42 -0700 (PDT) Received: by mail-wr1-x434.google.com with SMTP id ffacd0b85a97d-31aeee69de0so4493952f8f.2; Thu, 24 Aug 2023 06:31:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1692883901; x=1693488701; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=lRbZ/8a2wFTgwFE+Czu2PpLLLzMWLxHTHSPnuA9Gm+o=; b=oYWYvKePLZGjS+ZoEl8nqGnfKWJ/5ZYZqjbab0+kcN0rDQKfC+uPSsnIgWkMRmchaP kmB/bloU4msL5s6GFjkSzVQf8js0C978vVWo4JbuGczsYJ/hiJcB914hx8ipwG2pLE4r 5xV7/f4Hn73bYoAhdKka0EWmDvBuFjYAdFIL+QTaLTz04odlXiv4A1ZxyzykLLfmtDYe ZKWDxm+ZsoNc7WWZC2lUfFzhqCg8jcrKz+Y3S42S1EZz3NHqw0cr+G45BZdYegXPzh12 3c6OYT7W+bmFMjwwWfodGWLxbHSaXz5xU5SccK3v8bNMhYtWEHJSa0F0Rpaz0D6PcFD3 HFig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692883901; x=1693488701; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=lRbZ/8a2wFTgwFE+Czu2PpLLLzMWLxHTHSPnuA9Gm+o=; b=iaIa1HkAWiYwS/tw2lTm31ZJouXm3/EqVyq5D1xyCx0un8V/35vlobPc5Zu/jFC+xA z5kpGqXOEgvmh1jNj6ya9Ju7VqR2xn/4M7RAesxGcjCnzPooUXjywboivQMB2HnqVfo/ U1Bs+3zteMQeR+tKRaGr7y5VO0sjNNCoaHidIPoihcFA0Nwa4dF5aFO9TdHRX7dcPkMK fS/iLydRrU0V5rErm80kBTZkIR8HNcQBM5KOEj9GYczpLTzpTi4gb3weCu/NTUtBk4LX BqqgeyPHMLEBVZXqn9A0N+WakSYj9tGW4GUK1DGiDsi79z7NIGjI9qDiEGDAVoXWvSWd nJbQ== X-Gm-Message-State: AOJu0YxitLs45Gpn1OG0akF//Vt1IuwnEoq7SanJ8WVWysod4QtryJS2 tUqAKpaKVXM+lYZ1i/U/Njw= X-Google-Smtp-Source: AGHT+IHSeNPDuiAo4mvJL6SeFZqm5Y/OINirWF+gSjBoFG2Ur8fcxnPmq3uvy/x+VkYH3pkNmTQiNA== X-Received: by 2002:a5d:6084:0:b0:31a:d9bc:47a2 with SMTP id w4-20020a5d6084000000b0031ad9bc47a2mr13370813wrt.53.1692883901036; Thu, 24 Aug 2023 06:31:41 -0700 (PDT) Received: from ip-172-31-30-46.eu-west-1.compute.internal (ec2-54-170-241-106.eu-west-1.compute.amazonaws.com. [54.170.241.106]) by smtp.gmail.com with ESMTPSA id h11-20020a5d548b000000b00317e77106dbsm22396112wrv.48.2023.08.24.06.31.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 24 Aug 2023 06:31:39 -0700 (PDT) From: Puranjay Mohan To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, pulehui@huawei.com, conor.dooley@microchip.com, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, kpsingh@kernel.org, bjorn@kernel.org, bpf@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: puranjay12@gmail.com Subject: [PATCH bpf-next v2 2/3] riscv: implement a memset like function for text Date: Thu, 24 Aug 2023 13:31:34 +0000 Message-Id: <20230824133135.1176709-3-puranjay12@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230824133135.1176709-1-puranjay12@gmail.com> References: <20230824133135.1176709-1-puranjay12@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-1.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FROM,RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net The BPF JIT needs to write invalid instructions to RX regions of memory to invalidate removed BPF programs. This needs a function like memset() that can work with RX memory. Implement patch_text_set_nosync() which is similar to text_poke_set() of x86. Signed-off-by: Puranjay Mohan --- arch/riscv/include/asm/patch.h | 1 + arch/riscv/kernel/patch.c | 74 ++++++++++++++++++++++++++++++++++ 2 files changed, 75 insertions(+) diff --git a/arch/riscv/include/asm/patch.h b/arch/riscv/include/asm/patch.h index 63c98833d510..aa5c1830ea43 100644 --- a/arch/riscv/include/asm/patch.h +++ b/arch/riscv/include/asm/patch.h @@ -7,6 +7,7 @@ #define _ASM_RISCV_PATCH_H int patch_text_nosync(void *addr, const void *insns, size_t len); +int patch_text_set_nosync(void *addr, const int c, size_t len); int patch_text(void *addr, u32 *insns, int ninsns); extern int riscv_patch_in_stop_machine; diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c index 465b2eebbc37..24d49999ac1a 100644 --- a/arch/riscv/kernel/patch.c +++ b/arch/riscv/kernel/patch.c @@ -13,6 +13,7 @@ #include #include #include +#include struct patch_insn { void *addr; @@ -53,6 +54,34 @@ static void patch_unmap(int fixmap) } NOKPROBE_SYMBOL(patch_unmap); +static int __patch_insn_set(void *addr, const int c, size_t len) +{ + void *waddr = addr; + bool across_pages = (((uintptr_t) addr & ~PAGE_MASK) + len) > PAGE_SIZE; + int ret; + + /* + * Only two pages can be mapped at a time for writing. + */ + if (len > 2 * PAGE_SIZE) + return -EINVAL; + + if (across_pages) + patch_map(addr + PAGE_SIZE, FIX_TEXT_POKE1); + + waddr = patch_map(addr, FIX_TEXT_POKE0); + + memset(waddr, c, len); + + patch_unmap(FIX_TEXT_POKE0); + + if (across_pages) + patch_unmap(FIX_TEXT_POKE1); + + return 0; +} +NOKPROBE_SYMBOL(__patch_insn_set); + static int __patch_insn_write(void *addr, const void *insn, size_t len) { void *waddr = addr; @@ -95,6 +124,14 @@ static int __patch_insn_write(void *addr, const void *insn, size_t len) } NOKPROBE_SYMBOL(__patch_insn_write); #else +static int __patch_insn_set (void *addr, const int c, size_t len) +{ + memset(addr, c, len); + + return 0; +} +NOKPROBE_SYMBOL(__patch_insn_set); + static int __patch_insn_write(void *addr, const void *insn, size_t len) { return copy_to_kernel_nofault(addr, insn, len); @@ -102,6 +139,43 @@ static int __patch_insn_write(void *addr, const void *insn, size_t len) NOKPROBE_SYMBOL(__patch_insn_write); #endif /* CONFIG_MMU */ +static int patch_insn_set(void *addr, const int c, size_t len) +{ + size_t patched = 0; + size_t size; + int ret = 0; + + /* + * __patch_insn_set() can only work on 2 pages at a time so call it in a + * loop with len <= 2 * PAGE_SIZE. + */ + while (patched < len && !ret) { + size = min_t(size_t, + PAGE_SIZE * 2 - offset_in_page(addr + patched), + len - patched); + ret = __patch_insn_set(addr + patched, c, size); + + patched += size; + } + + return ret; +} +NOKPROBE_SYMBOL(patch_insn_set); + +int patch_text_set_nosync(void *addr, const int c, size_t len) +{ + u32 *tp = addr; + int ret; + + ret = patch_insn_set(tp, c, len); + + if (!ret) + flush_icache_range((uintptr_t) tp, (uintptr_t) tp + len); + + return ret; +} +NOKPROBE_SYMBOL(patch_text_set_nosync); + static int patch_insn_write(void *addr, const void *insn, size_t len) { size_t patched = 0; From patchwork Thu Aug 24 13:31:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Puranjay Mohan X-Patchwork-Id: 13364145 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7A595CA6E for ; 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[54.170.241.106]) by smtp.gmail.com with ESMTPSA id h11-20020a5d548b000000b00317e77106dbsm22396112wrv.48.2023.08.24.06.31.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 24 Aug 2023 06:31:41 -0700 (PDT) From: Puranjay Mohan To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, pulehui@huawei.com, conor.dooley@microchip.com, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, kpsingh@kernel.org, bjorn@kernel.org, bpf@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: puranjay12@gmail.com Subject: [PATCH bpf-next v2 3/3] bpf, riscv: use prog pack allocator in the BPF JIT Date: Thu, 24 Aug 2023 13:31:35 +0000 Message-Id: <20230824133135.1176709-4-puranjay12@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230824133135.1176709-1-puranjay12@gmail.com> References: <20230824133135.1176709-1-puranjay12@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-1.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net Use bpf_jit_binary_pack_alloc() for memory management of JIT binaries in RISCV BPF JIT. The bpf_jit_binary_pack_alloc creates a pair of RW and RX buffers. The JIT writes the program into the RW buffer. When the JIT is done, the program is copied to the final RX buffer with bpf_jit_binary_pack_finalize. Implement bpf_arch_text_copy() and bpf_arch_text_invalidate() for RISCV JIT as these functions are required by bpf_jit_binary_pack allocator. Signed-off-by: Puranjay Mohan Reviewed-by: Song Liu --- arch/riscv/net/bpf_jit.h | 3 + arch/riscv/net/bpf_jit_comp64.c | 56 +++++++++++++--- arch/riscv/net/bpf_jit_core.c | 113 +++++++++++++++++++++++++++----- 3 files changed, 146 insertions(+), 26 deletions(-) diff --git a/arch/riscv/net/bpf_jit.h b/arch/riscv/net/bpf_jit.h index 2717f5490428..ad69319c8ea7 100644 --- a/arch/riscv/net/bpf_jit.h +++ b/arch/riscv/net/bpf_jit.h @@ -68,6 +68,7 @@ static inline bool is_creg(u8 reg) struct rv_jit_context { struct bpf_prog *prog; u16 *insns; /* RV insns */ + u16 *ro_insns; int ninsns; int prologue_len; int epilogue_offset; @@ -85,7 +86,9 @@ static inline int ninsns_rvoff(int ninsns) struct rv_jit_data { struct bpf_binary_header *header; + struct bpf_binary_header *ro_header; u8 *image; + u8 *ro_image; struct rv_jit_context ctx; }; diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c index 0ca4f5c0097c..d77b16338ba2 100644 --- a/arch/riscv/net/bpf_jit_comp64.c +++ b/arch/riscv/net/bpf_jit_comp64.c @@ -144,7 +144,11 @@ static bool in_auipc_jalr_range(s64 val) /* Emit fixed-length instructions for address */ static int emit_addr(u8 rd, u64 addr, bool extra_pass, struct rv_jit_context *ctx) { - u64 ip = (u64)(ctx->insns + ctx->ninsns); + /* + * Use the ro_insns(RX) to calculate the offset as the BPF program will + * finally run from this memory region. + */ + u64 ip = (u64)(ctx->ro_insns + ctx->ninsns); s64 off = addr - ip; s64 upper = (off + (1 << 11)) >> 12; s64 lower = off & 0xfff; @@ -465,7 +469,11 @@ static int emit_call(u64 addr, bool fixed_addr, struct rv_jit_context *ctx) u64 ip; if (addr && ctx->insns) { - ip = (u64)(long)(ctx->insns + ctx->ninsns); + /* + * Use the ro_insns(RX) to calculate the offset as the BPF + * program will finally run from this memory region. + */ + ip = (u64)(long)(ctx->ro_insns + ctx->ninsns); off = addr - ip; } @@ -578,7 +586,8 @@ static int add_exception_handler(const struct bpf_insn *insn, { struct exception_table_entry *ex; unsigned long pc; - off_t offset; + off_t ins_offset; + off_t fixup_offset; if (!ctx->insns || !ctx->prog->aux->extable || BPF_MODE(insn->code) != BPF_PROBE_MEM) return 0; @@ -593,12 +602,17 @@ static int add_exception_handler(const struct bpf_insn *insn, return -EINVAL; ex = &ctx->prog->aux->extable[ctx->nexentries]; - pc = (unsigned long)&ctx->insns[ctx->ninsns - insn_len]; + pc = (unsigned long)&ctx->ro_insns[ctx->ninsns - insn_len]; - offset = pc - (long)&ex->insn; - if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN)) + /* + * This is the relative offset of the instruction that may fault from + * the exception table itself. This will be written to the exception + * table and if this instruction faults, the destination register will + * be set to '0' and the execution will jump to the next instruction. + */ + ins_offset = pc - (long)&ex->insn; + if (WARN_ON_ONCE(ins_offset >= 0 || ins_offset < INT_MIN)) return -ERANGE; - ex->insn = offset; /* * Since the extable follows the program, the fixup offset is always @@ -607,12 +621,25 @@ static int add_exception_handler(const struct bpf_insn *insn, * bits. We don't need to worry about buildtime or runtime sort * modifying the upper bits because the table is already sorted, and * isn't part of the main exception table. + * + * The fixup_offset is set to the next instruction from the instruction + * that may fault. The execution will jump to this after handling the + * fault. */ - offset = (long)&ex->fixup - (pc + insn_len * sizeof(u16)); - if (!FIELD_FIT(BPF_FIXUP_OFFSET_MASK, offset)) + fixup_offset = (long)&ex->fixup - (pc + insn_len * sizeof(u16)); + if (!FIELD_FIT(BPF_FIXUP_OFFSET_MASK, fixup_offset)) return -ERANGE; - ex->fixup = FIELD_PREP(BPF_FIXUP_OFFSET_MASK, offset) | + /* + * The offsets above have been calculated using the RO buffer but we + * need to use the R/W buffer for writes. + * switch ex to rw buffer for writing. + */ + ex = (void *)ctx->insns + ((void *)ex - (void *)ctx->ro_insns); + + ex->insn = ins_offset; + + ex->fixup = FIELD_PREP(BPF_FIXUP_OFFSET_MASK, fixup_offset) | FIELD_PREP(BPF_FIXUP_REG_MASK, dst_reg); ex->type = EX_TYPE_BPF; @@ -1006,6 +1033,7 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, ctx.ninsns = 0; ctx.insns = NULL; + ctx.ro_insns = NULL; ret = __arch_prepare_bpf_trampoline(im, m, tlinks, func_addr, flags, &ctx); if (ret < 0) return ret; @@ -1014,7 +1042,15 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, return -EFBIG; ctx.ninsns = 0; + /* + * The bpf_int_jit_compile() uses a RW buffer (ctx.insns) to write the + * JITed instructions and later copies it to a RX region (ctx.ro_insns). + * It also uses ctx.ro_insns to calculate offsets for jumps etc. As the + * trampoline image uses the same memory area for writing and execution, + * both ctx.insns and ctx.ro_insns can be set to image. + */ ctx.insns = image; + ctx.ro_insns = image; ret = __arch_prepare_bpf_trampoline(im, m, tlinks, func_addr, flags, &ctx); if (ret < 0) return ret; diff --git a/arch/riscv/net/bpf_jit_core.c b/arch/riscv/net/bpf_jit_core.c index 7a26a3e1c73c..4c8dffc09368 100644 --- a/arch/riscv/net/bpf_jit_core.c +++ b/arch/riscv/net/bpf_jit_core.c @@ -8,6 +8,8 @@ #include #include +#include +#include #include "bpf_jit.h" /* Number of iterations to try until offsets converge. */ @@ -117,16 +119,27 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) sizeof(struct exception_table_entry); prog_size = sizeof(*ctx->insns) * ctx->ninsns; - jit_data->header = - bpf_jit_binary_alloc(prog_size + extable_size, - &jit_data->image, - sizeof(u32), - bpf_fill_ill_insns); - if (!jit_data->header) { + jit_data->ro_header = + bpf_jit_binary_pack_alloc(prog_size + + extable_size, + &jit_data->ro_image, + sizeof(u32), + &jit_data->header, + &jit_data->image, + bpf_fill_ill_insns); + if (!jit_data->ro_header) { prog = orig_prog; goto out_offset; } + /* + * Use the image(RW) for writing the JITed instructions. But also save + * the ro_image(RX) for calculating the offsets in the image. The RW + * image will be later copied to the RX image from where the program + * will run. The bpf_jit_binary_pack_finalize() will do this copy in the + * final step. + */ + ctx->ro_insns = (u16 *)jit_data->ro_image; ctx->insns = (u16 *)jit_data->image; /* * Now, when the image is allocated, the image can @@ -138,14 +151,12 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) if (i == NR_JIT_ITERATIONS) { pr_err("bpf-jit: image did not converge in <%d passes!\n", i); - if (jit_data->header) - bpf_jit_binary_free(jit_data->header); prog = orig_prog; - goto out_offset; + goto out_free_hdr; } if (extable_size) - prog->aux->extable = (void *)ctx->insns + prog_size; + prog->aux->extable = (void *)ctx->ro_insns + prog_size; skip_init_ctx: pass++; @@ -154,23 +165,35 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) bpf_jit_build_prologue(ctx); if (build_body(ctx, extra_pass, NULL)) { - bpf_jit_binary_free(jit_data->header); prog = orig_prog; - goto out_offset; + goto out_free_hdr; } bpf_jit_build_epilogue(ctx); if (bpf_jit_enable > 1) bpf_jit_dump(prog->len, prog_size, pass, ctx->insns); - prog->bpf_func = (void *)ctx->insns; + prog->bpf_func = (void *)ctx->ro_insns; prog->jited = 1; prog->jited_len = prog_size; - bpf_flush_icache(jit_data->header, ctx->insns + ctx->ninsns); - if (!prog->is_func || extra_pass) { - bpf_jit_binary_lock_ro(jit_data->header); + if (WARN_ON(bpf_jit_binary_pack_finalize(prog, + jit_data->ro_header, + jit_data->header))) { + /* ro_header has been freed */ + jit_data->ro_header = NULL; + prog = orig_prog; + goto out_offset; + } + /* + * The instructions have now been copied to the ROX region from + * where they will execute. + * Write any modified data cache blocks out to memory and + * invalidate the corresponding blocks in the instruction cache. + */ + bpf_flush_icache(jit_data->ro_header, + ctx->ro_insns + ctx->ninsns); for (i = 0; i < prog->len; i++) ctx->offset[i] = ninsns_rvoff(ctx->offset[i]); bpf_prog_fill_jited_linfo(prog, ctx->offset); @@ -185,6 +208,15 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) bpf_jit_prog_release_other(prog, prog == orig_prog ? tmp : orig_prog); return prog; + +out_free_hdr: + if (jit_data->header) { + bpf_arch_text_copy(&jit_data->ro_header->size, + &jit_data->header->size, + sizeof(jit_data->header->size)); + bpf_jit_binary_pack_free(jit_data->ro_header, jit_data->header); + } + goto out_offset; } u64 bpf_jit_alloc_exec_limit(void) @@ -204,3 +236,52 @@ void bpf_jit_free_exec(void *addr) { return vfree(addr); } + +void *bpf_arch_text_copy(void *dst, void *src, size_t len) +{ + int ret; + + mutex_lock(&text_mutex); + ret = patch_text_nosync(dst, src, len); + mutex_unlock(&text_mutex); + + if (ret) + return ERR_PTR(-EINVAL); + + return dst; +} + +int bpf_arch_text_invalidate(void *dst, size_t len) +{ + int ret = 0; + + mutex_lock(&text_mutex); + ret = patch_text_set_nosync(dst, 0, len); + mutex_unlock(&text_mutex); + + return ret; +} + +void bpf_jit_free(struct bpf_prog *prog) +{ + if (prog->jited) { + struct rv_jit_data *jit_data = prog->aux->jit_data; + struct bpf_binary_header *hdr; + + /* + * If we fail the final pass of JIT (from jit_subprogs), + * the program may not be finalized yet. Call finalize here + * before freeing it. + */ + if (jit_data) { + bpf_jit_binary_pack_finalize(prog, jit_data->ro_header, + jit_data->header); + kfree(jit_data); + } + hdr = bpf_jit_binary_pack_hdr(prog); + bpf_jit_binary_pack_free(hdr, NULL); + WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(prog)); + } + + bpf_prog_unlock_free(prog); +}