From patchwork Tue May 21 10:48:17 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13669264 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 ABE696BFDC; Tue, 21 May 2024 10:48:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288525; cv=none; b=oqbXWtEnGGTdjA/CdkrIymMuK7R7syCcCpmDHQ7u1xhNuvJYZCWm/N6486PdLCjbS2AEcEiqR0UYV4GZh88J1cob2L/XUMbIf1yGc3/5zP7YwoCHgm+jeECm180z5vXRJgCTuxFPk1eWBQ91Z0EDDY5Vj58SM42b8VYB92fm0Gk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288525; c=relaxed/simple; bh=Z8DXNDPnmFnRTeFkXHNzbgWi0PNawYnnzOuslkQUpZU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Sa6y6sJXkqLUnNVFWZ4nwOjU5fNRaF7XivL2m0btHyjaUKadtG8Z0bVmVFxvE7eS+7/6TABBqUM7B9wxKn1d7Iu/ZTBTu4G7QGKzvu4SwYhuY/VZuGbY9B+LKj94UGeNb73T/gdbFGZuHoMo4rN4UIna2H4Mq3RE66h+l72aFyM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EfP4+Oh7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EfP4+Oh7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D191C2BD11; Tue, 21 May 2024 10:48:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716288525; bh=Z8DXNDPnmFnRTeFkXHNzbgWi0PNawYnnzOuslkQUpZU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EfP4+Oh7+GXfzLtJc1453I2ZgPPd2dt7EQilKIhug2ROnj/ux1URKK+GIinbYKVCC E+979p5uS2BS0DITqJk1NE5KO1dv0oY0wqR3VOKiuEJiZYyUKIXV9n5xLcIFjypnso nSeCdsa5A+H5S03zMTf0Dh9ScLbCv/0TlzEjQLN7V9jA/OjBHB/HVzKD3AfBjSSY1S Aw8CQR4PRjMDAzYmAs61o6bLipJpHxFwVA5eUqfqnr678k+SBTe+LCKE7tJUZR20gW XqQZ8/phLvB95M1VG4limxenOZvrMz5KYKyXdbnfkCH8rtR3PUQkhaBhERC89l3Pgm tSSIRITrhoALw== From: Jiri Olsa To: Steven Rostedt , Masami Hiramatsu , Oleg Nesterov , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-man@vger.kernel.org, x86@kernel.org, bpf@vger.kernel.org, Song Liu , Yonghong Song , John Fastabend , Peter Zijlstra , Thomas Gleixner , "Borislav Petkov (AMD)" , Ingo Molnar , Andy Lutomirski , "Edgecombe, Rick P" , Deepak Gupta Subject: [PATCHv6 bpf-next 1/9] x86/shstk: Make return uprobe work with shadow stack Date: Tue, 21 May 2024 12:48:17 +0200 Message-ID: <20240521104825.1060966-2-jolsa@kernel.org> X-Mailer: git-send-email 2.45.0 In-Reply-To: <20240521104825.1060966-1-jolsa@kernel.org> References: <20240521104825.1060966-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Currently the application with enabled shadow stack will crash if it sets up return uprobe. The reason is the uretprobe kernel code changes the user space task's stack, but does not update shadow stack accordingly. Adding new functions to update values on shadow stack and using them in uprobe code to keep shadow stack in sync with uretprobe changes to user stack. Fixes: 8b1c23543436 ("x86/shstk: Add return uprobe support") Signed-off-by: Jiri Olsa Reviewed-by: Oleg Nesterov Acked-by: Rick Edgecombe --- arch/x86/include/asm/shstk.h | 2 ++ arch/x86/kernel/shstk.c | 11 +++++++++++ arch/x86/kernel/uprobes.c | 7 ++++++- 3 files changed, 19 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/shstk.h b/arch/x86/include/asm/shstk.h index 42fee8959df7..896909f306e3 100644 --- a/arch/x86/include/asm/shstk.h +++ b/arch/x86/include/asm/shstk.h @@ -21,6 +21,7 @@ unsigned long shstk_alloc_thread_stack(struct task_struct *p, unsigned long clon void shstk_free(struct task_struct *p); int setup_signal_shadow_stack(struct ksignal *ksig); int restore_signal_shadow_stack(void); +int shstk_update_last_frame(unsigned long val); #else static inline long shstk_prctl(struct task_struct *task, int option, unsigned long arg2) { return -EINVAL; } @@ -31,6 +32,7 @@ static inline unsigned long shstk_alloc_thread_stack(struct task_struct *p, static inline void shstk_free(struct task_struct *p) {} static inline int setup_signal_shadow_stack(struct ksignal *ksig) { return 0; } static inline int restore_signal_shadow_stack(void) { return 0; } +static inline int shstk_update_last_frame(unsigned long val) { return 0; } #endif /* CONFIG_X86_USER_SHADOW_STACK */ #endif /* __ASSEMBLY__ */ diff --git a/arch/x86/kernel/shstk.c b/arch/x86/kernel/shstk.c index 6f1e9883f074..9797d4cdb78a 100644 --- a/arch/x86/kernel/shstk.c +++ b/arch/x86/kernel/shstk.c @@ -577,3 +577,14 @@ long shstk_prctl(struct task_struct *task, int option, unsigned long arg2) return wrss_control(true); return -EINVAL; } + +int shstk_update_last_frame(unsigned long val) +{ + unsigned long ssp; + + if (!features_enabled(ARCH_SHSTK_SHSTK)) + return 0; + + ssp = get_user_shstk_addr(); + return write_user_shstk_64((u64 __user *)ssp, (u64)val); +} diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 6c07f6daaa22..6402fb3089d2 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -1076,8 +1076,13 @@ arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs return orig_ret_vaddr; nleft = copy_to_user((void __user *)regs->sp, &trampoline_vaddr, rasize); - if (likely(!nleft)) + if (likely(!nleft)) { + if (shstk_update_last_frame(trampoline_vaddr)) { + force_sig(SIGSEGV); + return -1; + } return orig_ret_vaddr; + } if (nleft != rasize) { pr_err("return address clobbered: pid=%d, %%sp=%#lx, %%ip=%#lx\n", From patchwork Tue May 21 10:48:18 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13669265 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 37AE56D1BC; Tue, 21 May 2024 10:48:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288538; cv=none; b=qLPPxka34DfHPmYYYGiSd/sx8rPRiMQitEEndRM22fSjIqT7pqBfZabAgXx66By7XonfDTCfr+ijPNkJWfLU31u1XBZVS9CllvIHjA4om+u3NMAX52iCnID0Ccu5OyImBt4wCVe5NjGkcZmZQWeJgu2Vvokes28tpCLS9mYn8o8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288538; c=relaxed/simple; bh=Rwhd1hPDiyj5tuZNx5+dYKU/Rm8mY6QrTxHfDT/vTy8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ggtMBEdvMTET6Oskv7618ngFsh9VLwOn91I6YFEOIYEurk4cfwmL+t/h+J9/FejtbSqM6hE9EYRkkprtCXwKo5F5gM0VC19Xd7Q+QcmrvAyVNN4qIa3J3DhuMcoAk99qkrl7qa5MEesLy136cNreNBH9WmLX1X9dD0r5vs8Ioos= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LpYM/Nqi; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LpYM/Nqi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 952D2C2BD11; Tue, 21 May 2024 10:48:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716288537; bh=Rwhd1hPDiyj5tuZNx5+dYKU/Rm8mY6QrTxHfDT/vTy8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LpYM/NqiAFq/Ct+bnB0THT8cngkofO3MegOsNCqz5hAJLM3mK6wxV1c9gg+lZ6gQF pUIdn/rKrr2+5UsuTt8WFUkpodFo1t1bQU6OScojqMCVHL9vlmaJvp6bWrD9HfrMEE Z2yfnucBB/UU/uxyug0vZm7FvtAqvLJ9ShG8WbNos+401TmpCpyw9mjDDTV9Ei4MYb SyW/+r48nRWfV23Qy28WohLayFOaPW1fUuoIAzLbbwfk7cUOch6jxPZv+1wTWKTkcF djVmfk8BBpRQ9RtTOAJ5PEa9Szlb2d5p/kuZ+NPw9yxH7JYQ2OUH7tVv9lkK9LrVR3 rikASh35bP0XA== From: Jiri Olsa To: Steven Rostedt , Masami Hiramatsu , Oleg Nesterov , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-man@vger.kernel.org, x86@kernel.org, bpf@vger.kernel.org, Song Liu , Yonghong Song , John Fastabend , Peter Zijlstra , Thomas Gleixner , "Borislav Petkov (AMD)" , Ingo Molnar , Andy Lutomirski , "Edgecombe, Rick P" , Deepak Gupta Subject: [PATCHv6 bpf-next 2/9] uprobe: Wire up uretprobe system call Date: Tue, 21 May 2024 12:48:18 +0200 Message-ID: <20240521104825.1060966-3-jolsa@kernel.org> X-Mailer: git-send-email 2.45.0 In-Reply-To: <20240521104825.1060966-1-jolsa@kernel.org> References: <20240521104825.1060966-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Wiring up uretprobe system call, which comes in following changes. We need to do the wiring before, because the uretprobe implementation needs the syscall number. Note at the moment uretprobe syscall is supported only for native 64-bit process. Reviewed-by: Oleg Nesterov Reviewed-by: Masami Hiramatsu (Google) Acked-by: Andrii Nakryiko Signed-off-by: Jiri Olsa --- arch/x86/entry/syscalls/syscall_64.tbl | 1 + include/linux/syscalls.h | 2 ++ include/uapi/asm-generic/unistd.h | 5 ++++- kernel/sys_ni.c | 2 ++ 4 files changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index cc78226ffc35..47dfea0a827c 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -383,6 +383,7 @@ 459 common lsm_get_self_attr sys_lsm_get_self_attr 460 common lsm_set_self_attr sys_lsm_set_self_attr 461 common lsm_list_modules sys_lsm_list_modules +462 64 uretprobe sys_uretprobe # # Due to a historical design error, certain syscalls are numbered differently diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index e619ac10cd23..5318e0e76799 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -972,6 +972,8 @@ asmlinkage long sys_lsm_list_modules(u64 *ids, u32 *size, u32 flags); /* x86 */ asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int on); +asmlinkage long sys_uretprobe(void); + /* pciconfig: alpha, arm, arm64, ia64, sparc */ asmlinkage long sys_pciconfig_read(unsigned long bus, unsigned long dfn, unsigned long off, unsigned long len, diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index 75f00965ab15..8a747cd1d735 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -842,8 +842,11 @@ __SYSCALL(__NR_lsm_set_self_attr, sys_lsm_set_self_attr) #define __NR_lsm_list_modules 461 __SYSCALL(__NR_lsm_list_modules, sys_lsm_list_modules) +#define __NR_uretprobe 462 +__SYSCALL(__NR_uretprobe, sys_uretprobe) + #undef __NR_syscalls -#define __NR_syscalls 462 +#define __NR_syscalls 463 /* * 32 bit systems traditionally used different diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index faad00cce269..be6195e0d078 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -391,3 +391,5 @@ COND_SYSCALL(setuid16); /* restartable sequence */ COND_SYSCALL(rseq); + +COND_SYSCALL(uretprobe); From patchwork Tue May 21 10:48:19 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13669266 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8D5C871754; Tue, 21 May 2024 10:49:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288551; cv=none; b=SJ+i6G+h7mNnOqmSd7sxdXKWhRGj3AVT71xu5XvIMRENwkJl6FfGJ7md/TYoLre+fZF+D6UjXwtYAwtEGBxwAPCKN3CGw+Ln9QHn4/DL5DpwUUI36yiceDutgAuYs2X913Cg0Fmz6vVxkSZrZtXw3+KK6Bahz5I58OB4k4qMDxc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288551; c=relaxed/simple; bh=T1aGzZCLnTUkeB//lixQ3x0kCUqVyFRJjpxJToZe7vs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=GMiRPUiCsoMSYGpA6+faTbY4zXcxaQEtrZlpOf1t/U7/kizMlbzKVh0VTLyxcoNo/lxolwNk3TtkzQS0gt1tWbQvL/f1ztRxmXNSvf2mHGJ0BuGKpnLg9fuyBAirZCHGKUKYj6a13+BeSWJ9lQiBFX0UOhf+YN9gAaQewWTfGkI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cvmGAKgB; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cvmGAKgB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AED15C2BD11; Tue, 21 May 2024 10:49:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716288551; bh=T1aGzZCLnTUkeB//lixQ3x0kCUqVyFRJjpxJToZe7vs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cvmGAKgBKJMOgBxSelvt4SUAyQfOxwXwUY1euQeTokNJRy+kDXYaLcCMyV1/ZDRsK QajjdEdQvhIhGVtN1PeaL25vxqHLG7NfuDTXYgw0YUFsS/E2VXny0FpF59M5UUpwI0 WBkFPMX+zoyk/bB10AeIkOn08Xk7+vdnp0gWOkAtYID2PsjefTzsuebFJ2soJ2PlP+ u4KZrTMcGfBnanafHBFfcEHAamm1bEoyqAegYS+IXVtAAijBvwbID0m/Gwm4NxjZCz MSxFKmcmm/lmQ9RsWQBEfTyo2TfC5UiNT81sFBqvPzC1LaQjmqsQk/nF8u/SO1SGc3 +CiZuJgAR/UcQ== From: Jiri Olsa To: Steven Rostedt , Masami Hiramatsu , Oleg Nesterov , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-man@vger.kernel.org, x86@kernel.org, bpf@vger.kernel.org, Song Liu , Yonghong Song , John Fastabend , Peter Zijlstra , Thomas Gleixner , "Borislav Petkov (AMD)" , Ingo Molnar , Andy Lutomirski , "Edgecombe, Rick P" , Deepak Gupta Subject: [PATCHv6 bpf-next 3/9] uprobe: Add uretprobe syscall to speed up return probe Date: Tue, 21 May 2024 12:48:19 +0200 Message-ID: <20240521104825.1060966-4-jolsa@kernel.org> X-Mailer: git-send-email 2.45.0 In-Reply-To: <20240521104825.1060966-1-jolsa@kernel.org> References: <20240521104825.1060966-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Adding uretprobe syscall instead of trap to speed up return probe. At the moment the uretprobe setup/path is: - install entry uprobe - when the uprobe is hit, it overwrites probed function's return address on stack with address of the trampoline that contains breakpoint instruction - the breakpoint trap code handles the uretprobe consumers execution and jumps back to original return address This patch replaces the above trampoline's breakpoint instruction with new ureprobe syscall call. This syscall does exactly the same job as the trap with some more extra work: - syscall trampoline must save original value for rax/r11/rcx registers on stack - rax is set to syscall number and r11/rcx are changed and used by syscall instruction - the syscall code reads the original values of those registers and restore those values in task's pt_regs area - only caller from trampoline exposed in '[uprobes]' is allowed, the process will receive SIGILL signal otherwise Even with some extra work, using the uretprobes syscall shows speed improvement (compared to using standard breakpoint): On Intel (11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz) current: uretprobe-nop : 1.498 ± 0.000M/s uretprobe-push : 1.448 ± 0.001M/s uretprobe-ret : 0.816 ± 0.001M/s with the fix: uretprobe-nop : 1.969 ± 0.002M/s < 31% speed up uretprobe-push : 1.910 ± 0.000M/s < 31% speed up uretprobe-ret : 0.934 ± 0.000M/s < 14% speed up On Amd (AMD Ryzen 7 5700U) current: uretprobe-nop : 0.778 ± 0.001M/s uretprobe-push : 0.744 ± 0.001M/s uretprobe-ret : 0.540 ± 0.001M/s with the fix: uretprobe-nop : 0.860 ± 0.001M/s < 10% speed up uretprobe-push : 0.818 ± 0.001M/s < 10% speed up uretprobe-ret : 0.578 ± 0.000M/s < 7% speed up The performance test spawns a thread that runs loop which triggers uprobe with attached bpf program that increments the counter that gets printed in results above. The uprobe (and uretprobe) kind is determined by which instruction is being patched with breakpoint instruction. That's also important for uretprobes, because uprobe is installed for each uretprobe. The performance test is part of bpf selftests: tools/testing/selftests/bpf/run_bench_uprobes.sh Note at the moment uretprobe syscall is supported only for native 64-bit process, compat process still uses standard breakpoint. Note that when shadow stack is enabled the uretprobe syscall returns via iret, which is slower than return via sysret, but won't cause the shadow stack violation. Suggested-by: Andrii Nakryiko Reviewed-by: Oleg Nesterov Reviewed-by: Masami Hiramatsu (Google) Acked-by: Andrii Nakryiko Signed-off-by: Oleg Nesterov Signed-off-by: Jiri Olsa --- arch/x86/include/asm/shstk.h | 2 + arch/x86/kernel/shstk.c | 5 ++ arch/x86/kernel/uprobes.c | 117 +++++++++++++++++++++++++++++++++++ include/linux/uprobes.h | 3 + kernel/events/uprobes.c | 24 ++++--- 5 files changed, 144 insertions(+), 7 deletions(-) diff --git a/arch/x86/include/asm/shstk.h b/arch/x86/include/asm/shstk.h index 896909f306e3..4cb77e004615 100644 --- a/arch/x86/include/asm/shstk.h +++ b/arch/x86/include/asm/shstk.h @@ -22,6 +22,7 @@ void shstk_free(struct task_struct *p); int setup_signal_shadow_stack(struct ksignal *ksig); int restore_signal_shadow_stack(void); int shstk_update_last_frame(unsigned long val); +bool shstk_is_enabled(void); #else static inline long shstk_prctl(struct task_struct *task, int option, unsigned long arg2) { return -EINVAL; } @@ -33,6 +34,7 @@ static inline void shstk_free(struct task_struct *p) {} static inline int setup_signal_shadow_stack(struct ksignal *ksig) { return 0; } static inline int restore_signal_shadow_stack(void) { return 0; } static inline int shstk_update_last_frame(unsigned long val) { return 0; } +static inline bool shstk_is_enabled(void) { return false; } #endif /* CONFIG_X86_USER_SHADOW_STACK */ #endif /* __ASSEMBLY__ */ diff --git a/arch/x86/kernel/shstk.c b/arch/x86/kernel/shstk.c index 9797d4cdb78a..059685612362 100644 --- a/arch/x86/kernel/shstk.c +++ b/arch/x86/kernel/shstk.c @@ -588,3 +588,8 @@ int shstk_update_last_frame(unsigned long val) ssp = get_user_shstk_addr(); return write_user_shstk_64((u64 __user *)ssp, (u64)val); } + +bool shstk_is_enabled(void) +{ + return features_enabled(ARCH_SHSTK_SHSTK); +} diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 6402fb3089d2..5a952c5ea66b 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include @@ -308,6 +309,122 @@ static int uprobe_init_insn(struct arch_uprobe *auprobe, struct insn *insn, bool } #ifdef CONFIG_X86_64 + +asm ( + ".pushsection .rodata\n" + ".global uretprobe_trampoline_entry\n" + "uretprobe_trampoline_entry:\n" + "pushq %rax\n" + "pushq %rcx\n" + "pushq %r11\n" + "movq $" __stringify(__NR_uretprobe) ", %rax\n" + "syscall\n" + ".global uretprobe_syscall_check\n" + "uretprobe_syscall_check:\n" + "popq %r11\n" + "popq %rcx\n" + + /* The uretprobe syscall replaces stored %rax value with final + * return address, so we don't restore %rax in here and just + * call ret. + */ + "retq\n" + ".global uretprobe_trampoline_end\n" + "uretprobe_trampoline_end:\n" + ".popsection\n" +); + +extern u8 uretprobe_trampoline_entry[]; +extern u8 uretprobe_trampoline_end[]; +extern u8 uretprobe_syscall_check[]; + +void *arch_uprobe_trampoline(unsigned long *psize) +{ + static uprobe_opcode_t insn = UPROBE_SWBP_INSN; + struct pt_regs *regs = task_pt_regs(current); + + /* + * At the moment the uretprobe syscall trampoline is supported + * only for native 64-bit process, the compat process still uses + * standard breakpoint. + */ + if (user_64bit_mode(regs)) { + *psize = uretprobe_trampoline_end - uretprobe_trampoline_entry; + return uretprobe_trampoline_entry; + } + + *psize = UPROBE_SWBP_INSN_SIZE; + return &insn; +} + +static unsigned long trampoline_check_ip(void) +{ + unsigned long tramp = uprobe_get_trampoline_vaddr(); + + return tramp + (uretprobe_syscall_check - uretprobe_trampoline_entry); +} + +SYSCALL_DEFINE0(uretprobe) +{ + struct pt_regs *regs = task_pt_regs(current); + unsigned long err, ip, sp, r11_cx_ax[3]; + + if (regs->ip != trampoline_check_ip()) + goto sigill; + + err = copy_from_user(r11_cx_ax, (void __user *)regs->sp, sizeof(r11_cx_ax)); + if (err) + goto sigill; + + /* expose the "right" values of r11/cx/ax/sp to uprobe_consumer/s */ + regs->r11 = r11_cx_ax[0]; + regs->cx = r11_cx_ax[1]; + regs->ax = r11_cx_ax[2]; + regs->sp += sizeof(r11_cx_ax); + regs->orig_ax = -1; + + ip = regs->ip; + sp = regs->sp; + + uprobe_handle_trampoline(regs); + + /* + * Some of the uprobe consumers has changed sp, we can do nothing, + * just return via iret. + * .. or shadow stack is enabled, in which case we need to skip + * return through the user space stack address. + */ + if (regs->sp != sp || shstk_is_enabled()) + return regs->ax; + regs->sp -= sizeof(r11_cx_ax); + + /* for the case uprobe_consumer has changed r11/cx */ + r11_cx_ax[0] = regs->r11; + r11_cx_ax[1] = regs->cx; + + /* + * ax register is passed through as return value, so we can use + * its space on stack for ip value and jump to it through the + * trampoline's ret instruction + */ + r11_cx_ax[2] = regs->ip; + regs->ip = ip; + + err = copy_to_user((void __user *)regs->sp, r11_cx_ax, sizeof(r11_cx_ax)); + if (err) + goto sigill; + + /* ensure sysret, see do_syscall_64() */ + regs->r11 = regs->flags; + regs->cx = regs->ip; + + return regs->ax; + +sigill: + force_sig(SIGILL); + return -1; +} + /* * If arch_uprobe->insn doesn't use rip-relative addressing, return * immediately. Otherwise, rewrite the instruction so that it accesses diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index f46e0ca0169c..b503fafb7fb3 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -138,6 +138,9 @@ extern bool arch_uretprobe_is_alive(struct return_instance *ret, enum rp_check c extern bool arch_uprobe_ignore(struct arch_uprobe *aup, struct pt_regs *regs); extern void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr, void *src, unsigned long len); +extern void uprobe_handle_trampoline(struct pt_regs *regs); +extern void *arch_uprobe_trampoline(unsigned long *psize); +extern unsigned long uprobe_get_trampoline_vaddr(void); #else /* !CONFIG_UPROBES */ struct uprobes_state { }; diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 2c83ba776fc7..2816e65729ac 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1474,11 +1474,20 @@ static int xol_add_vma(struct mm_struct *mm, struct xol_area *area) return ret; } +void * __weak arch_uprobe_trampoline(unsigned long *psize) +{ + static uprobe_opcode_t insn = UPROBE_SWBP_INSN; + + *psize = UPROBE_SWBP_INSN_SIZE; + return &insn; +} + static struct xol_area *__create_xol_area(unsigned long vaddr) { struct mm_struct *mm = current->mm; - uprobe_opcode_t insn = UPROBE_SWBP_INSN; + unsigned long insns_size; struct xol_area *area; + void *insns; area = kmalloc(sizeof(*area), GFP_KERNEL); if (unlikely(!area)) @@ -1502,7 +1511,8 @@ static struct xol_area *__create_xol_area(unsigned long vaddr) /* Reserve the 1st slot for get_trampoline_vaddr() */ set_bit(0, area->bitmap); atomic_set(&area->slot_count, 1); - arch_uprobe_copy_ixol(area->pages[0], 0, &insn, UPROBE_SWBP_INSN_SIZE); + insns = arch_uprobe_trampoline(&insns_size); + arch_uprobe_copy_ixol(area->pages[0], 0, insns, insns_size); if (!xol_add_vma(mm, area)) return area; @@ -1827,7 +1837,7 @@ void uprobe_copy_process(struct task_struct *t, unsigned long flags) * * Returns -1 in case the xol_area is not allocated. */ -static unsigned long get_trampoline_vaddr(void) +unsigned long uprobe_get_trampoline_vaddr(void) { struct xol_area *area; unsigned long trampoline_vaddr = -1; @@ -1878,7 +1888,7 @@ static void prepare_uretprobe(struct uprobe *uprobe, struct pt_regs *regs) if (!ri) return; - trampoline_vaddr = get_trampoline_vaddr(); + trampoline_vaddr = uprobe_get_trampoline_vaddr(); orig_ret_vaddr = arch_uretprobe_hijack_return_addr(trampoline_vaddr, regs); if (orig_ret_vaddr == -1) goto fail; @@ -2123,7 +2133,7 @@ static struct return_instance *find_next_ret_chain(struct return_instance *ri) return ri; } -static void handle_trampoline(struct pt_regs *regs) +void uprobe_handle_trampoline(struct pt_regs *regs) { struct uprobe_task *utask; struct return_instance *ri, *next; @@ -2187,8 +2197,8 @@ static void handle_swbp(struct pt_regs *regs) int is_swbp; bp_vaddr = uprobe_get_swbp_addr(regs); - if (bp_vaddr == get_trampoline_vaddr()) - return handle_trampoline(regs); + if (bp_vaddr == uprobe_get_trampoline_vaddr()) + return uprobe_handle_trampoline(regs); uprobe = find_active_uprobe(bp_vaddr, &is_swbp); if (!uprobe) { From patchwork Tue May 21 10:48:20 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13669267 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 976B9219EB; Tue, 21 May 2024 10:49:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288563; cv=none; b=BWwX6fUVKiAYeUJbr8337reONGx/K3Y3MpzM36tYtUARWL3dtBN7EP0ZIXr2Y/fvi9Wt9SoRuI2I/vsyoGU3m0jOv5FP/ibFHUJUjIc4i55alwYY6cqRepeezo1yTMp8GaoIWei3Ue+5Jy7an8UDatjSLEE2RkQKACkthN324Ts= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288563; c=relaxed/simple; bh=TlvkotYY4vT5pChu211KhwIQkqphsg5aK16HXMTrdK8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SZg9Sc6rnUMOQxUy6SCR1OcZR1XoyJH7H2dS/aKKNUG/fqDZCZitsaRgxFzQ8TqCkCyU+tBL5RC3uvRS/ob7L40fykiLWc1bWUMkTXR5o2OelEf7HY2RrZMI0xVAZSk37rDyD0oGGkblTwXwbrb1ZkolS/+Bpq0lP6iTRceca/g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DiPhc3yH; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DiPhc3yH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 62DDDC32789; Tue, 21 May 2024 10:49:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716288563; bh=TlvkotYY4vT5pChu211KhwIQkqphsg5aK16HXMTrdK8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DiPhc3yHftqJFKCo2U8HXhMyT6uDynpq/oRZGRNHajMLZyVztgn7UoUdROUWJzWqz +1bBicsDn7miwu735faA+S67Dh6le7sm+IVolJ7lmWP6SWB/qqmjuoDIoJgDXt/M6e Qd66LyykCbAXKSnChDSlp+ud2hdsps7zLLutYS5oOyOGyP7m7zMDNCEAaqr0fnMRua KItUMCWyg8lsFTRP6ez4bL4eI2YzZKocJ4+JER3q6BmDt+3xUl9ui79u+zpX2ccWBM 2wqYTwXey7sMbYfCROBq0iIlIZ/zOZl7BSz6RRucAAX0uEX5yQaZ6ZEb76z+HGKq3q QRt6ZVKQgQhxQ== From: Jiri Olsa To: Steven Rostedt , Masami Hiramatsu , Oleg Nesterov , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-man@vger.kernel.org, x86@kernel.org, bpf@vger.kernel.org, Song Liu , Yonghong Song , John Fastabend , Peter Zijlstra , Thomas Gleixner , "Borislav Petkov (AMD)" , Ingo Molnar , Andy Lutomirski , "Edgecombe, Rick P" , Deepak Gupta Subject: [PATCHv6 bpf-next 4/9] selftests/x86: Add return uprobe shadow stack test Date: Tue, 21 May 2024 12:48:20 +0200 Message-ID: <20240521104825.1060966-5-jolsa@kernel.org> X-Mailer: git-send-email 2.45.0 In-Reply-To: <20240521104825.1060966-1-jolsa@kernel.org> References: <20240521104825.1060966-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Adding return uprobe test for shadow stack and making sure it's working properly. Borrowed some of the code from bpf selftests. Signed-off-by: Jiri Olsa --- .../testing/selftests/x86/test_shadow_stack.c | 145 ++++++++++++++++++ 1 file changed, 145 insertions(+) diff --git a/tools/testing/selftests/x86/test_shadow_stack.c b/tools/testing/selftests/x86/test_shadow_stack.c index 757e6527f67e..e3501b7e2ecc 100644 --- a/tools/testing/selftests/x86/test_shadow_stack.c +++ b/tools/testing/selftests/x86/test_shadow_stack.c @@ -34,6 +34,7 @@ #include #include #include +#include /* * Define the ABI defines if needed, so people can run the tests @@ -681,6 +682,144 @@ int test_32bit(void) return !segv_triggered; } +static int parse_uint_from_file(const char *file, const char *fmt) +{ + int err, ret; + FILE *f; + + f = fopen(file, "re"); + if (!f) { + err = -errno; + printf("failed to open '%s': %d\n", file, err); + return err; + } + err = fscanf(f, fmt, &ret); + if (err != 1) { + err = err == EOF ? -EIO : -errno; + printf("failed to parse '%s': %d\n", file, err); + fclose(f); + return err; + } + fclose(f); + return ret; +} + +static int determine_uprobe_perf_type(void) +{ + const char *file = "/sys/bus/event_source/devices/uprobe/type"; + + return parse_uint_from_file(file, "%d\n"); +} + +static int determine_uprobe_retprobe_bit(void) +{ + const char *file = "/sys/bus/event_source/devices/uprobe/format/retprobe"; + + return parse_uint_from_file(file, "config:%d\n"); +} + +static ssize_t get_uprobe_offset(const void *addr) +{ + size_t start, end, base; + char buf[256]; + bool found = false; + FILE *f; + + f = fopen("/proc/self/maps", "r"); + if (!f) + return -errno; + + while (fscanf(f, "%zx-%zx %s %zx %*[^\n]\n", &start, &end, buf, &base) == 4) { + if (buf[2] == 'x' && (uintptr_t)addr >= start && (uintptr_t)addr < end) { + found = true; + break; + } + } + + fclose(f); + + if (!found) + return -ESRCH; + + return (uintptr_t)addr - start + base; +} + +static __attribute__((noinline)) void uretprobe_trigger(void) +{ + asm volatile (""); +} + +/* + * This test setups return uprobe, which is sensitive to shadow stack + * (crashes without extra fix). After executing the uretprobe we fail + * the test if we receive SIGSEGV, no crash means we're good. + * + * Helper functions above borrowed from bpf selftests. + */ +static int test_uretprobe(void) +{ + const size_t attr_sz = sizeof(struct perf_event_attr); + const char *file = "/proc/self/exe"; + int bit, fd = 0, type, err = 1; + struct perf_event_attr attr; + struct sigaction sa = {}; + ssize_t offset; + + type = determine_uprobe_perf_type(); + if (type < 0) { + if (type == -ENOENT) + printf("[SKIP]\tUretprobe test, uprobes are not available\n"); + return 0; + } + + offset = get_uprobe_offset(uretprobe_trigger); + if (offset < 0) + return 1; + + bit = determine_uprobe_retprobe_bit(); + if (bit < 0) + return 1; + + sa.sa_sigaction = segv_gp_handler; + sa.sa_flags = SA_SIGINFO; + if (sigaction(SIGSEGV, &sa, NULL)) + return 1; + + /* Setup return uprobe through perf event interface. */ + memset(&attr, 0, attr_sz); + attr.size = attr_sz; + attr.type = type; + attr.config = 1 << bit; + attr.config1 = (__u64) (unsigned long) file; + attr.config2 = offset; + + fd = syscall(__NR_perf_event_open, &attr, 0 /* pid */, -1 /* cpu */, + -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC); + if (fd < 0) + goto out; + + if (sigsetjmp(jmp_buffer, 1)) + goto out; + + ARCH_PRCTL(ARCH_SHSTK_ENABLE, ARCH_SHSTK_SHSTK); + + /* + * This either segfaults and goes through sigsetjmp above + * or succeeds and we're good. + */ + uretprobe_trigger(); + + printf("[OK]\tUretprobe test\n"); + err = 0; + +out: + ARCH_PRCTL(ARCH_SHSTK_DISABLE, ARCH_SHSTK_SHSTK); + signal(SIGSEGV, SIG_DFL); + if (fd) + close(fd); + return err; +} + void segv_handler_ptrace(int signum, siginfo_t *si, void *uc) { /* The SSP adjustment caused a segfault. */ @@ -867,6 +1006,12 @@ int main(int argc, char *argv[]) goto out; } + if (test_uretprobe()) { + ret = 1; + printf("[FAIL]\turetprobe test\n"); + goto out; + } + return ret; out: From patchwork Tue May 21 10:48:21 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13669268 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 536FF6F086; Tue, 21 May 2024 10:49:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288575; cv=none; b=byUjrFjwXFIcy9zFHCfw1b41i0r4pJKj7QphtE3YfbrsHXO7FPR0SqAIOlSDqkBB2kEUrc7PzyQxfHDta2qBoZk0pmyUWxQqwFkfF3ioI3fRCuR0+seDREDJL4QtrAjslHm361ojNPm4IL9/c+a0Lo0vqUXmWXtg81SJJ0FHjj8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288575; c=relaxed/simple; bh=lW/3gzi9X62qpxx+XfjSgU8B5H9BM2eiM14Ks29Hm10=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CbdTmaxIU4INWE8yOGJoTLyScYJwAe9Az4anLmZ9plUZxAU+ClvscVfcwTACmE0yWWphYXw1rwfbf5sT1QZ5p2Lo457sO4Oojaf4h/9Kj3x2YIhjvyVCDZyK0sEUK/LL7xQzG8ZJQzpapg3UetgdLzgf5diIensCIncAbaFnwvA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FVc8/R1L; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FVc8/R1L" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66D0BC4AF0E; Tue, 21 May 2024 10:49:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716288575; bh=lW/3gzi9X62qpxx+XfjSgU8B5H9BM2eiM14Ks29Hm10=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FVc8/R1L53KFJ48iZ2iLycmDxu2dE/vQ1Rvh3NzcIN7CKenZYw1e3JV0c/1YeyywX leHFIQl+Fx6M2GM7FPiI7eH3cW9fvW4ihrWK4WoyAYr+Ser7ZcEO3a8oMoM/O3jFqu UD3i4ITyufjg80zLH0O9CJ/Zvrcw1BftjhfPIxcjnWHkl9sgrb56pjSFaGO9u8GsK6 WiW8K4bAKNPjLJa9Jpjarv6b7TUVYLmpkbi+ru6uRs7zhgMtHiXrYTZA1QFdCimkdR qRPfB1SAbBWNc1IoiXpDL7jOByIKNPFk5aAhACPmrpKEIaTUCdLBDhOopclEyxcboV qWfDbKlVWzF8Q== From: Jiri Olsa To: Steven Rostedt , Masami Hiramatsu , Oleg Nesterov , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-man@vger.kernel.org, x86@kernel.org, bpf@vger.kernel.org, Song Liu , Yonghong Song , John Fastabend , Peter Zijlstra , Thomas Gleixner , "Borislav Petkov (AMD)" , Ingo Molnar , Andy Lutomirski , "Edgecombe, Rick P" , Deepak Gupta Subject: [PATCHv6 bpf-next 5/9] selftests/bpf: Add uretprobe syscall test for regs integrity Date: Tue, 21 May 2024 12:48:21 +0200 Message-ID: <20240521104825.1060966-6-jolsa@kernel.org> X-Mailer: git-send-email 2.45.0 In-Reply-To: <20240521104825.1060966-1-jolsa@kernel.org> References: <20240521104825.1060966-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add uretprobe syscall test that compares register values before and after the uretprobe is hit. It also compares the register values seen from attached bpf program. Acked-by: Andrii Nakryiko Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Jiri Olsa --- tools/include/linux/compiler.h | 4 + .../selftests/bpf/prog_tests/uprobe_syscall.c | 163 ++++++++++++++++++ .../selftests/bpf/progs/uprobe_syscall.c | 15 ++ 3 files changed, 182 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c create mode 100644 tools/testing/selftests/bpf/progs/uprobe_syscall.c diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h index 8a63a9913495..6f7f22ac9da5 100644 --- a/tools/include/linux/compiler.h +++ b/tools/include/linux/compiler.h @@ -62,6 +62,10 @@ #define __nocf_check __attribute__((nocf_check)) #endif +#ifndef __naked +#define __naked __attribute__((__naked__)) +#endif + /* Are two types/vars the same type (ignoring qualifiers)? */ #ifndef __same_type # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c new file mode 100644 index 000000000000..311ac19d8992 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c @@ -0,0 +1,163 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +#ifdef __x86_64__ + +#include +#include +#include +#include "uprobe_syscall.skel.h" + +__naked unsigned long uretprobe_regs_trigger(void) +{ + asm volatile ( + "movq $0xdeadbeef, %rax\n" + "ret\n" + ); +} + +__naked void uretprobe_regs(struct pt_regs *before, struct pt_regs *after) +{ + asm volatile ( + "movq %r15, 0(%rdi)\n" + "movq %r14, 8(%rdi)\n" + "movq %r13, 16(%rdi)\n" + "movq %r12, 24(%rdi)\n" + "movq %rbp, 32(%rdi)\n" + "movq %rbx, 40(%rdi)\n" + "movq %r11, 48(%rdi)\n" + "movq %r10, 56(%rdi)\n" + "movq %r9, 64(%rdi)\n" + "movq %r8, 72(%rdi)\n" + "movq %rax, 80(%rdi)\n" + "movq %rcx, 88(%rdi)\n" + "movq %rdx, 96(%rdi)\n" + "movq %rsi, 104(%rdi)\n" + "movq %rdi, 112(%rdi)\n" + "movq $0, 120(%rdi)\n" /* orig_rax */ + "movq $0, 128(%rdi)\n" /* rip */ + "movq $0, 136(%rdi)\n" /* cs */ + "pushf\n" + "pop %rax\n" + "movq %rax, 144(%rdi)\n" /* eflags */ + "movq %rsp, 152(%rdi)\n" /* rsp */ + "movq $0, 160(%rdi)\n" /* ss */ + + /* save 2nd argument */ + "pushq %rsi\n" + "call uretprobe_regs_trigger\n" + + /* save return value and load 2nd argument pointer to rax */ + "pushq %rax\n" + "movq 8(%rsp), %rax\n" + + "movq %r15, 0(%rax)\n" + "movq %r14, 8(%rax)\n" + "movq %r13, 16(%rax)\n" + "movq %r12, 24(%rax)\n" + "movq %rbp, 32(%rax)\n" + "movq %rbx, 40(%rax)\n" + "movq %r11, 48(%rax)\n" + "movq %r10, 56(%rax)\n" + "movq %r9, 64(%rax)\n" + "movq %r8, 72(%rax)\n" + "movq %rcx, 88(%rax)\n" + "movq %rdx, 96(%rax)\n" + "movq %rsi, 104(%rax)\n" + "movq %rdi, 112(%rax)\n" + "movq $0, 120(%rax)\n" /* orig_rax */ + "movq $0, 128(%rax)\n" /* rip */ + "movq $0, 136(%rax)\n" /* cs */ + + /* restore return value and 2nd argument */ + "pop %rax\n" + "pop %rsi\n" + + "movq %rax, 80(%rsi)\n" + + "pushf\n" + "pop %rax\n" + + "movq %rax, 144(%rsi)\n" /* eflags */ + "movq %rsp, 152(%rsi)\n" /* rsp */ + "movq $0, 160(%rsi)\n" /* ss */ + "ret\n" +); +} + +static void test_uretprobe_regs_equal(void) +{ + struct uprobe_syscall *skel = NULL; + struct pt_regs before = {}, after = {}; + unsigned long *pb = (unsigned long *) &before; + unsigned long *pa = (unsigned long *) &after; + unsigned long *pp; + unsigned int i, cnt; + int err; + + skel = uprobe_syscall__open_and_load(); + if (!ASSERT_OK_PTR(skel, "uprobe_syscall__open_and_load")) + goto cleanup; + + err = uprobe_syscall__attach(skel); + if (!ASSERT_OK(err, "uprobe_syscall__attach")) + goto cleanup; + + uretprobe_regs(&before, &after); + + pp = (unsigned long *) &skel->bss->regs; + cnt = sizeof(before)/sizeof(*pb); + + for (i = 0; i < cnt; i++) { + unsigned int offset = i * sizeof(unsigned long); + + /* + * Check register before and after uretprobe_regs_trigger call + * that triggers the uretprobe. + */ + switch (offset) { + case offsetof(struct pt_regs, rax): + ASSERT_EQ(pa[i], 0xdeadbeef, "return value"); + break; + default: + if (!ASSERT_EQ(pb[i], pa[i], "register before-after value check")) + fprintf(stdout, "failed register offset %u\n", offset); + } + + /* + * Check register seen from bpf program and register after + * uretprobe_regs_trigger call + */ + switch (offset) { + /* + * These values will be different (not set in uretprobe_regs), + * we don't care. + */ + case offsetof(struct pt_regs, orig_rax): + case offsetof(struct pt_regs, rip): + case offsetof(struct pt_regs, cs): + case offsetof(struct pt_regs, rsp): + case offsetof(struct pt_regs, ss): + break; + default: + if (!ASSERT_EQ(pp[i], pa[i], "register prog-after value check")) + fprintf(stdout, "failed register offset %u\n", offset); + } + } + +cleanup: + uprobe_syscall__destroy(skel); +} +#else +static void test_uretprobe_regs_equal(void) +{ + test__skip(); +} +#endif + +void test_uprobe_syscall(void) +{ + if (test__start_subtest("uretprobe_regs_equal")) + test_uretprobe_regs_equal(); +} diff --git a/tools/testing/selftests/bpf/progs/uprobe_syscall.c b/tools/testing/selftests/bpf/progs/uprobe_syscall.c new file mode 100644 index 000000000000..8a4fa6c7ef59 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/uprobe_syscall.c @@ -0,0 +1,15 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "vmlinux.h" +#include +#include + +struct pt_regs regs; + +char _license[] SEC("license") = "GPL"; + +SEC("uretprobe//proc/self/exe:uretprobe_regs_trigger") +int uretprobe(struct pt_regs *ctx) +{ + __builtin_memcpy(®s, ctx, sizeof(regs)); + return 0; +} From patchwork Tue May 21 10:48:22 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13669269 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 EEDD96F086; Tue, 21 May 2024 10:49:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288588; cv=none; b=tC5jXK9Rn/8ExtZd6GsGPl7+ueBiKF+cAhTsS3Zqjnr2mZOwgnhRVIcwkF6JDxT9LpKHSRbcj5g3fW+H4vGOS1s35IhxxifSJDri9urPoZl9d5m0YhWT8myhCw0mFcRZodD5bThmp979ZoKiRV2BPKVsbXXfRu24qL1VPfJHTbc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288588; c=relaxed/simple; bh=6Rn1oqgl6PL1+fcYKfZc7ZqYMMU121MwU600zJGLrpc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Tic0LW0BHmshTZ1ZweExKP6YsiaTquZ5hM/gPL8hyhbK46GCbwDLW3n+hV2tRFjZc9ECtlHxDu1evyeM4JMwy3zzqv6pl+U1XbFNjJHdqbxHSJL0bzTrf7dqjRkh0n1465b04X3OJkzcyo2tU1i/EUx84SCrx60Yjre425D4l0g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=M+cdfzvQ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="M+cdfzvQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5C528C2BD11; Tue, 21 May 2024 10:49:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716288587; bh=6Rn1oqgl6PL1+fcYKfZc7ZqYMMU121MwU600zJGLrpc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=M+cdfzvQzGx0MK7r7WxZJ8pDTUAn+TMJFeNjRj7CFs/Q6kHgFpwoa45ncRPy4q88i Ct4C1qdtf0SmO4nR2D/tqNsgbWrdmqw/8Z/3xfPgSNVf2SevvW9QJYNK8fYTT8nPgP qLFmo5M3/3MVjJWjtH0N4QBFwa0PU44FOPJ3pC1Q6EBhJgPqiioVRvd/JpN7OJk2nf 50npAtk6JENm/JUigcQLPtq8mFiRBWJOZ26CFr6LDqA4V5biVxa+EJfaxJEiNqELXC Qj86TImkDhz7DAYq43ZgpF2habhwTSvv7lLcveVYycvgilokFFz/cFiMdWjYRUSz46 yXoyBF3LJFGYw== From: Jiri Olsa To: Steven Rostedt , Masami Hiramatsu , Oleg Nesterov , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-man@vger.kernel.org, x86@kernel.org, bpf@vger.kernel.org, Song Liu , Yonghong Song , John Fastabend , Peter Zijlstra , Thomas Gleixner , "Borislav Petkov (AMD)" , Ingo Molnar , Andy Lutomirski , "Edgecombe, Rick P" , Deepak Gupta Subject: [PATCHv6 bpf-next 6/9] selftests/bpf: Add uretprobe syscall test for regs changes Date: Tue, 21 May 2024 12:48:22 +0200 Message-ID: <20240521104825.1060966-7-jolsa@kernel.org> X-Mailer: git-send-email 2.45.0 In-Reply-To: <20240521104825.1060966-1-jolsa@kernel.org> References: <20240521104825.1060966-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Adding test that creates uprobe consumer on uretprobe which changes some of the registers. Making sure the changed registers are propagated to the user space when the ureptobe syscall trampoline is used on x86_64. To be able to do this, adding support to bpf_testmod to create uprobe via new attribute file: /sys/kernel/bpf_testmod_uprobe This file is expecting file offset and creates related uprobe on current process exe file and removes existing uprobe if offset is 0. The can be only single uprobe at any time. The uprobe has specific consumer that changes registers used in ureprobe syscall trampoline and which are later checked in the test. Acked-by: Andrii Nakryiko Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Jiri Olsa --- .../selftests/bpf/bpf_testmod/bpf_testmod.c | 123 +++++++++++++++++- .../selftests/bpf/prog_tests/uprobe_syscall.c | 67 ++++++++++ 2 files changed, 189 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c index 2a18bd320e92..b0132a342bb5 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "bpf_testmod.h" #include "bpf_testmod_kfunc.h" @@ -358,6 +359,119 @@ static struct bin_attribute bin_attr_bpf_testmod_file __ro_after_init = { .write = bpf_testmod_test_write, }; +/* bpf_testmod_uprobe sysfs attribute is so far enabled for x86_64 only, + * please see test_uretprobe_regs_change test + */ +#ifdef __x86_64__ + +static int +uprobe_ret_handler(struct uprobe_consumer *self, unsigned long func, + struct pt_regs *regs) + +{ + regs->ax = 0x12345678deadbeef; + regs->cx = 0x87654321feebdaed; + regs->r11 = (u64) -1; + return true; +} + +struct testmod_uprobe { + struct path path; + loff_t offset; + struct uprobe_consumer consumer; +}; + +static DEFINE_MUTEX(testmod_uprobe_mutex); + +static struct testmod_uprobe uprobe = { + .consumer.ret_handler = uprobe_ret_handler, +}; + +static int testmod_register_uprobe(loff_t offset) +{ + int err = -EBUSY; + + if (uprobe.offset) + return -EBUSY; + + mutex_lock(&testmod_uprobe_mutex); + + if (uprobe.offset) + goto out; + + err = kern_path("/proc/self/exe", LOOKUP_FOLLOW, &uprobe.path); + if (err) + goto out; + + err = uprobe_register_refctr(d_real_inode(uprobe.path.dentry), + offset, 0, &uprobe.consumer); + if (err) + path_put(&uprobe.path); + else + uprobe.offset = offset; + +out: + mutex_unlock(&testmod_uprobe_mutex); + return err; +} + +static void testmod_unregister_uprobe(void) +{ + mutex_lock(&testmod_uprobe_mutex); + + if (uprobe.offset) { + uprobe_unregister(d_real_inode(uprobe.path.dentry), + uprobe.offset, &uprobe.consumer); + uprobe.offset = 0; + } + + mutex_unlock(&testmod_uprobe_mutex); +} + +static ssize_t +bpf_testmod_uprobe_write(struct file *file, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t len) +{ + unsigned long offset = 0; + int err = 0; + + if (kstrtoul(buf, 0, &offset)) + return -EINVAL; + + if (offset) + err = testmod_register_uprobe(offset); + else + testmod_unregister_uprobe(); + + return err ?: strlen(buf); +} + +static struct bin_attribute bin_attr_bpf_testmod_uprobe_file __ro_after_init = { + .attr = { .name = "bpf_testmod_uprobe", .mode = 0666, }, + .write = bpf_testmod_uprobe_write, +}; + +static int register_bpf_testmod_uprobe(void) +{ + return sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_uprobe_file); +} + +static void unregister_bpf_testmod_uprobe(void) +{ + testmod_unregister_uprobe(); + sysfs_remove_bin_file(kernel_kobj, &bin_attr_bpf_testmod_uprobe_file); +} + +#else +static int register_bpf_testmod_uprobe(void) +{ + return 0; +} + +static void unregister_bpf_testmod_uprobe(void) { } +#endif + BTF_KFUNCS_START(bpf_testmod_common_kfunc_ids) BTF_ID_FLAGS(func, bpf_iter_testmod_seq_new, KF_ITER_NEW) BTF_ID_FLAGS(func, bpf_iter_testmod_seq_next, KF_ITER_NEXT | KF_RET_NULL) @@ -912,7 +1026,13 @@ static int bpf_testmod_init(void) return -EINVAL; sock = NULL; mutex_init(&sock_lock); - return sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file); + ret = sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file); + if (ret < 0) + return ret; + ret = register_bpf_testmod_uprobe(); + if (ret < 0) + return ret; + return 0; } static void bpf_testmod_exit(void) @@ -927,6 +1047,7 @@ static void bpf_testmod_exit(void) bpf_kfunc_close_sock(); sysfs_remove_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file); + unregister_bpf_testmod_uprobe(); } module_init(bpf_testmod_init); diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c index 311ac19d8992..1a50cd35205d 100644 --- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c @@ -149,15 +149,82 @@ static void test_uretprobe_regs_equal(void) cleanup: uprobe_syscall__destroy(skel); } + +#define BPF_TESTMOD_UPROBE_TEST_FILE "/sys/kernel/bpf_testmod_uprobe" + +static int write_bpf_testmod_uprobe(unsigned long offset) +{ + size_t n, ret; + char buf[30]; + int fd; + + n = sprintf(buf, "%lu", offset); + + fd = open(BPF_TESTMOD_UPROBE_TEST_FILE, O_WRONLY); + if (fd < 0) + return -errno; + + ret = write(fd, buf, n); + close(fd); + return ret != n ? (int) ret : 0; +} + +static void test_uretprobe_regs_change(void) +{ + struct pt_regs before = {}, after = {}; + unsigned long *pb = (unsigned long *) &before; + unsigned long *pa = (unsigned long *) &after; + unsigned long cnt = sizeof(before)/sizeof(*pb); + unsigned int i, err, offset; + + offset = get_uprobe_offset(uretprobe_regs_trigger); + + err = write_bpf_testmod_uprobe(offset); + if (!ASSERT_OK(err, "register_uprobe")) + return; + + uretprobe_regs(&before, &after); + + err = write_bpf_testmod_uprobe(0); + if (!ASSERT_OK(err, "unregister_uprobe")) + return; + + for (i = 0; i < cnt; i++) { + unsigned int offset = i * sizeof(unsigned long); + + switch (offset) { + case offsetof(struct pt_regs, rax): + ASSERT_EQ(pa[i], 0x12345678deadbeef, "rax"); + break; + case offsetof(struct pt_regs, rcx): + ASSERT_EQ(pa[i], 0x87654321feebdaed, "rcx"); + break; + case offsetof(struct pt_regs, r11): + ASSERT_EQ(pa[i], (__u64) -1, "r11"); + break; + default: + if (!ASSERT_EQ(pa[i], pb[i], "register before-after value check")) + fprintf(stdout, "failed register offset %u\n", offset); + } + } +} + #else static void test_uretprobe_regs_equal(void) { test__skip(); } + +static void test_uretprobe_regs_change(void) +{ + test__skip(); +} #endif void test_uprobe_syscall(void) { if (test__start_subtest("uretprobe_regs_equal")) test_uretprobe_regs_equal(); + if (test__start_subtest("uretprobe_regs_change")) + test_uretprobe_regs_change(); } From patchwork Tue May 21 10:48:23 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13669270 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4372F73194; Tue, 21 May 2024 10:49:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288600; cv=none; b=GEb7dUaaXsVDvOKLFFKLzNKfe6nbx1YxVupRYgN0TNi+4m4M90Z1IjIecqLV/5dvyyClsKSkIBhhxbDGZYuaArWTBapRmkOjZ5odF4xjvHFmoj88cd+VrOd/RpdfynoQ926GoBBxa1qyWOrY9GBFtU4P7/uVpvlVoi+bkFPrl88= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288600; c=relaxed/simple; bh=fhIu4hEsIOsOTozlOQHoi5IPGvZcip9NRTcmMNDhE4Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OM7BZYx2cv5ado/7ye+qFm32AmKPBvpIKK7AkPz0HSxJOF5jGeS1fuiutfNAHV9DMhZyEsF46P8JJDGIL5pGaXwN1qOaoTe8/1eted0BNskbompcBKIYw5yefzJ3BZ51hejjZmz1jNhE/kYOtBa64fB8dofkEJcOKYJJTx19KEc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oND2ZFGZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oND2ZFGZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A219EC2BD11; Tue, 21 May 2024 10:49:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716288599; bh=fhIu4hEsIOsOTozlOQHoi5IPGvZcip9NRTcmMNDhE4Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oND2ZFGZF9ZsQhTJXctFSkiioRlt7bfrvUOptnlkArTj2H1140BYyJwv9uZ5Udp1E UBBJ1vB4y9bnTBCK42VU0FhFtJ1ZI0GWZACrd1HC9nX0lCwEbTJhrLUsn2DpunTH3m TEsFIx5oqv27CLcNegjQ7rJsDB2wiI3tQGdI3yAzxjDoX+/X03WPluxMs6XQIOOSij 8fpidg+tvEqWI8E11RLPB+RootPNHkVh3CnUFUuXwJPjJwhI82j39pq1S74Gb7vEe/ 6gz9PbX6gBi1/d+L/uU3Ki7uRc81RYfiELt0JCWpPhU7Z771odDlwiOq5UTO40TE3w lTPOdSemIroFg== From: Jiri Olsa To: Steven Rostedt , Masami Hiramatsu , Oleg Nesterov , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-man@vger.kernel.org, x86@kernel.org, bpf@vger.kernel.org, Song Liu , Yonghong Song , John Fastabend , Peter Zijlstra , Thomas Gleixner , "Borislav Petkov (AMD)" , Ingo Molnar , Andy Lutomirski , "Edgecombe, Rick P" , Deepak Gupta Subject: [PATCHv6 bpf-next 7/9] selftests/bpf: Add uretprobe syscall call from user space test Date: Tue, 21 May 2024 12:48:23 +0200 Message-ID: <20240521104825.1060966-8-jolsa@kernel.org> X-Mailer: git-send-email 2.45.0 In-Reply-To: <20240521104825.1060966-1-jolsa@kernel.org> References: <20240521104825.1060966-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Adding test to verify that when called from outside of the trampoline provided by kernel, the uretprobe syscall will cause calling process to receive SIGILL signal and the attached bpf program is not executed. Acked-by: Andrii Nakryiko Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Jiri Olsa --- .../selftests/bpf/prog_tests/uprobe_syscall.c | 95 +++++++++++++++++++ .../bpf/progs/uprobe_syscall_executed.c | 17 ++++ 2 files changed, 112 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c index 1a50cd35205d..3ef324c2db50 100644 --- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c @@ -7,7 +7,10 @@ #include #include #include +#include +#include #include "uprobe_syscall.skel.h" +#include "uprobe_syscall_executed.skel.h" __naked unsigned long uretprobe_regs_trigger(void) { @@ -209,6 +212,91 @@ static void test_uretprobe_regs_change(void) } } +#ifndef __NR_uretprobe +#define __NR_uretprobe 462 +#endif + +__naked unsigned long uretprobe_syscall_call_1(void) +{ + /* + * Pretend we are uretprobe trampoline to trigger the return + * probe invocation in order to verify we get SIGILL. + */ + asm volatile ( + "pushq %rax\n" + "pushq %rcx\n" + "pushq %r11\n" + "movq $" __stringify(__NR_uretprobe) ", %rax\n" + "syscall\n" + "popq %r11\n" + "popq %rcx\n" + "retq\n" + ); +} + +__naked unsigned long uretprobe_syscall_call(void) +{ + asm volatile ( + "call uretprobe_syscall_call_1\n" + "retq\n" + ); +} + +static void test_uretprobe_syscall_call(void) +{ + LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, + .retprobe = true, + ); + struct uprobe_syscall_executed *skel; + int pid, status, err, go[2], c; + + if (ASSERT_OK(pipe(go), "pipe")) + return; + + skel = uprobe_syscall_executed__open_and_load(); + if (!ASSERT_OK_PTR(skel, "uprobe_syscall_executed__open_and_load")) + goto cleanup; + + pid = fork(); + if (!ASSERT_GE(pid, 0, "fork")) + goto cleanup; + + /* child */ + if (pid == 0) { + close(go[1]); + + /* wait for parent's kick */ + err = read(go[0], &c, 1); + if (err != 1) + exit(-1); + + uretprobe_syscall_call(); + _exit(0); + } + + skel->links.test = bpf_program__attach_uprobe_multi(skel->progs.test, pid, + "/proc/self/exe", + "uretprobe_syscall_call", &opts); + if (!ASSERT_OK_PTR(skel->links.test, "bpf_program__attach_uprobe_multi")) + goto cleanup; + + /* kick the child */ + write(go[1], &c, 1); + err = waitpid(pid, &status, 0); + ASSERT_EQ(err, pid, "waitpid"); + + /* verify the child got killed with SIGILL */ + ASSERT_EQ(WIFSIGNALED(status), 1, "WIFSIGNALED"); + ASSERT_EQ(WTERMSIG(status), SIGILL, "WTERMSIG"); + + /* verify the uretprobe program wasn't called */ + ASSERT_EQ(skel->bss->executed, 0, "executed"); + +cleanup: + uprobe_syscall_executed__destroy(skel); + close(go[1]); + close(go[0]); +} #else static void test_uretprobe_regs_equal(void) { @@ -219,6 +307,11 @@ static void test_uretprobe_regs_change(void) { test__skip(); } + +static void test_uretprobe_syscall_call(void) +{ + test__skip(); +} #endif void test_uprobe_syscall(void) @@ -227,4 +320,6 @@ void test_uprobe_syscall(void) test_uretprobe_regs_equal(); if (test__start_subtest("uretprobe_regs_change")) test_uretprobe_regs_change(); + if (test__start_subtest("uretprobe_syscall_call")) + test_uretprobe_syscall_call(); } diff --git a/tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c b/tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c new file mode 100644 index 000000000000..0d7f1a7db2e2 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c @@ -0,0 +1,17 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "vmlinux.h" +#include +#include + +struct pt_regs regs; + +char _license[] SEC("license") = "GPL"; + +int executed = 0; + +SEC("uretprobe.multi") +int test(struct pt_regs *regs) +{ + executed = 1; + return 0; +} From patchwork Tue May 21 10:48:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13669271 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 EFFE46D1BC; Tue, 21 May 2024 10:50:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288612; cv=none; b=Bl8TpK1+yvt4AMVxG+5++m3kN89jBF3gJAB56vhxDUVRFApGTamBsCyTEl3f55F4IZQ07tSk1DEX3ZbfF4ONfAQpjdY9Ohq7LwYXEkdzof1FyAfe8OtUh3Z0DQTiKOu4BEn44asloQ667Pbj7fodeHlvj8GyYc4uRrmgqMoe82g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288612; c=relaxed/simple; bh=n/oAy5vJBvR1F5+qZWIuxrNBXKK0jB6rNDZbMLCp8L8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=o6UPiAWtiPF8cFjgpbpn9YJskw9QIUbtlcyNjf7MBoGzWorSRK3IOm9Mnn6+ln9yHCr+HT5JVAgajTpX+KnCOGvSF5tNNPU0yxBs4RUZ1FRmgTKL1WF/ObdXXbMWSWkldGdXYsCKJA9I4du8bkBQ1VA4cd2Tf7NMQwiLm5kAbEI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BidipBjr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="BidipBjr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E8B7BC2BD11; Tue, 21 May 2024 10:50:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716288611; bh=n/oAy5vJBvR1F5+qZWIuxrNBXKK0jB6rNDZbMLCp8L8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BidipBjrGuOkSoCJXdzboXiMvk2URky/b33HNpaGWJeUHyhqmKZS0OY9NUF9hcHb7 6ie3tZdttprh1P9doOvDqnaQq4dtM++Pwem1Iqw5jwBxjU1nc2ctH8vDeucDTmSxqH DmH7Dpe5eAn1gBD5e5TERM9HuHJp+TDqomJ4uz92gwssuxkmZJ4JV6raoZw1PjLn5K wK7Qw139BYrqlgSyF4fOYjCfWZDJsVKbsTMvxC+WrLfSl92f8fRbzEMbXYeDkMW2NC 3H5cwzIVjiyC4CTb578+XkLarmsYLvVYirxPHdws2MuGC+cdG0pxza3/c019sMX+WF 7nRFnK+VteRIw== From: Jiri Olsa To: Steven Rostedt , Masami Hiramatsu , Oleg Nesterov , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-man@vger.kernel.org, x86@kernel.org, bpf@vger.kernel.org, Song Liu , Yonghong Song , John Fastabend , Peter Zijlstra , Thomas Gleixner , "Borislav Petkov (AMD)" , Ingo Molnar , Andy Lutomirski , "Edgecombe, Rick P" , Deepak Gupta Subject: [PATCHv6 bpf-next 8/9] selftests/bpf: Add uretprobe shadow stack test Date: Tue, 21 May 2024 12:48:24 +0200 Message-ID: <20240521104825.1060966-9-jolsa@kernel.org> X-Mailer: git-send-email 2.45.0 In-Reply-To: <20240521104825.1060966-1-jolsa@kernel.org> References: <20240521104825.1060966-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Adding uretprobe shadow stack test that runs all existing uretprobe tests with shadow stack enabled if it's available. Signed-off-by: Jiri Olsa --- .../selftests/bpf/prog_tests/uprobe_syscall.c | 60 +++++++++++++++++++ 1 file changed, 60 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c index 3ef324c2db50..fda456401284 100644 --- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c @@ -9,6 +9,9 @@ #include #include #include +#include +#include +#include #include "uprobe_syscall.skel.h" #include "uprobe_syscall_executed.skel.h" @@ -297,6 +300,56 @@ static void test_uretprobe_syscall_call(void) close(go[1]); close(go[0]); } + +/* + * Borrowed from tools/testing/selftests/x86/test_shadow_stack.c. + * + * For use in inline enablement of shadow stack. + * + * The program can't return from the point where shadow stack gets enabled + * because there will be no address on the shadow stack. So it can't use + * syscall() for enablement, since it is a function. + * + * Based on code from nolibc.h. Keep a copy here because this can't pull + * in all of nolibc.h. + */ +#define ARCH_PRCTL(arg1, arg2) \ +({ \ + long _ret; \ + register long _num asm("eax") = __NR_arch_prctl; \ + register long _arg1 asm("rdi") = (long)(arg1); \ + register long _arg2 asm("rsi") = (long)(arg2); \ + \ + asm volatile ( \ + "syscall\n" \ + : "=a"(_ret) \ + : "r"(_arg1), "r"(_arg2), \ + "0"(_num) \ + : "rcx", "r11", "memory", "cc" \ + ); \ + _ret; \ +}) + +#ifndef ARCH_SHSTK_ENABLE +#define ARCH_SHSTK_ENABLE 0x5001 +#define ARCH_SHSTK_DISABLE 0x5002 +#define ARCH_SHSTK_SHSTK (1ULL << 0) +#endif + +static void test_uretprobe_shadow_stack(void) +{ + if (ARCH_PRCTL(ARCH_SHSTK_ENABLE, ARCH_SHSTK_SHSTK)) { + test__skip(); + return; + } + + /* Run all of the uretprobe tests. */ + test_uretprobe_regs_equal(); + test_uretprobe_regs_change(); + test_uretprobe_syscall_call(); + + ARCH_PRCTL(ARCH_SHSTK_DISABLE, ARCH_SHSTK_SHSTK); +} #else static void test_uretprobe_regs_equal(void) { @@ -312,6 +365,11 @@ static void test_uretprobe_syscall_call(void) { test__skip(); } + +static void test_uretprobe_shadow_stack(void) +{ + test__skip(); +} #endif void test_uprobe_syscall(void) @@ -322,4 +380,6 @@ void test_uprobe_syscall(void) test_uretprobe_regs_change(); if (test__start_subtest("uretprobe_syscall_call")) test_uretprobe_syscall_call(); + if (test__start_subtest("uretprobe_shadow_stack")) + test_uretprobe_shadow_stack(); } From patchwork Tue May 21 10:48:25 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13669272 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 7A97873173; Tue, 21 May 2024 10:50:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288624; cv=none; b=HK/A6NmF+on0jUB4lArA0vorZkv7hzEaVcxBOde3o1vBWew1SPOET3LGA6o5R/06aA+EqAQH3yLOrq0VYcSwPBBS5y61jODn8QIhlUObcfNnEqTJLZDMmS3ygbb+fRba1288GHxOZAarMRWfNUZVbGiGmniNVfzYsYOKpsKm9QM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716288624; c=relaxed/simple; bh=YOJAMtCe8DK1ux8SakApe84VXlSr5Oi60Hn13JG7aeE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NGg+AbSHaig26OewEKEWmiQd5MBHF/ME/k22kITgpTUP7fAN4CM4M1CYSk5lNbV65ApHyNZEW/GiTBKuje7X7y7RAh/zCVfVbKGO8TQSc/jbZUae9+bVZQoov5SIGHNsnRo4ljcBiGQ/FC5q0Ov47gPOvPu/4pjSeJuhrD/VjgQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=r6Gtns3+; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="r6Gtns3+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E526EC2BD11; Tue, 21 May 2024 10:50:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716288624; bh=YOJAMtCe8DK1ux8SakApe84VXlSr5Oi60Hn13JG7aeE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r6Gtns3+EMo4boeflOX9A0YnShB9U6p772Ihi403MnCCYGGoKfoZo7bSuQ7XrrnrY luxesIqv7GkZyJUc5lO+DSO/ft4OqIy0c/qQg5ftHEHHmZZODQKonagHIRqfGjH/Kz n2+iHDPWtYjBq456+Z+Kdb/IV11nGCKSx+yvKH/qlROFLw4/EYEs5dyp9phI/XL7Fi zfi2Ruz2ur43lbunsLkzGBubg0+MNh9jtYKpVqpj+QMBOU5SKAQAAfJAOBk5GvpW3D qmGEPAT+YegAT6I0bv6xMmlraGQCMpGohCS/5UpPWLeh4pwZBKqxJPVdaYNTz8nv0x ygkMXgc9GcNew== From: Jiri Olsa To: Steven Rostedt , Masami Hiramatsu , Oleg Nesterov , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-man@vger.kernel.org, x86@kernel.org, bpf@vger.kernel.org, Song Liu , Yonghong Song , John Fastabend , Peter Zijlstra , Thomas Gleixner , "Borislav Petkov (AMD)" , Ingo Molnar , Andy Lutomirski , "Edgecombe, Rick P" , Deepak Gupta Subject: [PATCHv6 9/9] man2: Add uretprobe syscall page Date: Tue, 21 May 2024 12:48:25 +0200 Message-ID: <20240521104825.1060966-10-jolsa@kernel.org> X-Mailer: git-send-email 2.45.0 In-Reply-To: <20240521104825.1060966-1-jolsa@kernel.org> References: <20240521104825.1060966-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Adding man page for new uretprobe syscall. Signed-off-by: Jiri Olsa --- man2/uretprobe.2 | 50 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 man2/uretprobe.2 diff --git a/man2/uretprobe.2 b/man2/uretprobe.2 new file mode 100644 index 000000000000..690fe3b1a44f --- /dev/null +++ b/man2/uretprobe.2 @@ -0,0 +1,50 @@ +.\" Copyright (C) 2024, Jiri Olsa +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.TH uretprobe 2 (date) "Linux man-pages (unreleased)" +.SH NAME +uretprobe \- execute pending return uprobes +.SH SYNOPSIS +.nf +.B int uretprobe(void) +.fi +.SH DESCRIPTION +The +.BR uretprobe () +syscall is an alternative to breakpoint instructions for +triggering return uprobe consumers. +.P +Calls to +.BR uretprobe () +suscall are only made from the user-space trampoline provided by the kernel. +Calls from any other place result in a +.BR SIGILL . + +.SH RETURN VALUE +The +.BR uretprobe () +syscall return value is architecture-specific. + +.SH VERSIONS +This syscall is not specified in POSIX, +and details of its behavior vary across systems. +.SH STANDARDS +None. +.SH HISTORY +TBD +.SH NOTES +The +.BR uretprobe () +syscall was initially introduced for the x86_64 architecture where it was shown +to be faster than breakpoint traps. It might be extended to other architectures. +.P +The +.BR uretprobe () +syscall exists only to allow the invocation of return uprobe consumers. +It should +.B never +be called directly. +Details of the arguments (if any) passed to +.BR uretprobe () +and the return value are architecture-specific.