From: madvenka@linux.microsoft.com To: kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, oleg@redhat.com, x86@kernel.org, luto@kernel.org, David.Laight@ACULAB.COM, fweimer@redhat.com, mark.rutland@arm.com, mic@digikod.net, pavel@ucw.cz, madvenka@linux.microsoft.com Subject: [PATCH v2 4/4] [RFC] arm/trampfd: Provide support for the trampoline file descriptor Date: Tue, 22 Sep 2020 16:53:26 -0500 [thread overview] Message-ID: <20200922215326.4603-5-madvenka@linux.microsoft.com> (raw) In-Reply-To: <20200922215326.4603-1-madvenka@linux.microsoft.com> From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com> - Define architecture specific register names - Architecture specific functions for: - system call init - code descriptor check - data descriptor check - Fill a page with a trampoline table, Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com> --- arch/arm/include/uapi/asm/ptrace.h | 21 +++++ arch/arm/kernel/Makefile | 1 + arch/arm/kernel/trampfd.c | 124 +++++++++++++++++++++++++++++ arch/arm/tools/syscall.tbl | 1 + 4 files changed, 147 insertions(+) create mode 100644 arch/arm/kernel/trampfd.c diff --git a/arch/arm/include/uapi/asm/ptrace.h b/arch/arm/include/uapi/asm/ptrace.h index e61c65b4018d..598047768f9b 100644 --- a/arch/arm/include/uapi/asm/ptrace.h +++ b/arch/arm/include/uapi/asm/ptrace.h @@ -151,6 +151,27 @@ struct pt_regs { #define ARM_r0 uregs[0] #define ARM_ORIG_r0 uregs[17] +/* + * These register names are to be used by 32-bit applications. + */ +enum reg_32_name { + arm_min, + arm_r0 = arm_min, + arm_r1, + arm_r2, + arm_r3, + arm_r4, + arm_r5, + arm_r6, + arm_r7, + arm_r8, + arm_r9, + arm_r10, + arm_r11, + arm_r12, + arm_max, +}; + /* * The size of the user-visible VFP state as seen by PTRACE_GET/SETVFPREGS * and core dumps. diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 89e5d864e923..652c54c2f19a 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -105,5 +105,6 @@ obj-$(CONFIG_SMP) += psci_smp.o endif obj-$(CONFIG_HAVE_ARM_SMCCC) += smccc-call.o +obj-$(CONFIG_TRAMPFD) += trampfd.o extra-y := $(head-y) vmlinux.lds diff --git a/arch/arm/kernel/trampfd.c b/arch/arm/kernel/trampfd.c new file mode 100644 index 000000000000..45146ed489e8 --- /dev/null +++ b/arch/arm/kernel/trampfd.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Trampoline FD - ARM support. + * + * Author: Madhavan T. Venkataraman (madvenka@linux.microsoft.com) + * + * Copyright (c) 2020, Microsoft Corporation. + */ + +#include <linux/thread_info.h> +#include <linux/trampfd.h> + +#define TRAMPFD_CODE_SIZE 28 + +/* + * trampfd syscall. + */ +void trampfd_arch(struct trampfd_info *info) +{ + info->code_size = TRAMPFD_CODE_SIZE; + info->ntrampolines = PAGE_SIZE / info->code_size; + info->code_offset = TRAMPFD_CODE_PGOFF << PAGE_SHIFT; + info->reserved = 0; +} + +/* + * trampfd code descriptor check. + */ +int trampfd_code_arch(struct trampfd_code *code) +{ + int ntrampolines; + int min, max; + + min = arm_min; + max = arm_max; + ntrampolines = PAGE_SIZE / TRAMPFD_CODE_SIZE; + + if (code->reg < min || code->reg >= max) + return -EINVAL; + + if (!code->ntrampolines || code->ntrampolines > ntrampolines) + return -EINVAL; + return 0; +} + +/* + * trampfd data descriptor check. + */ +int trampfd_data_arch(struct trampfd_data *data) +{ + int min, max; + + min = arm_min; + max = arm_max; + + if (data->reg < min || data->reg >= max) + return -EINVAL; + return 0; +} + +#define MOVW(ins, reg, imm32) \ +{ \ + u16 *_imm16 = (u16 *) &(imm32); /* little endian */ \ + int _hw, _opcode; \ + \ + for (_hw = 0; _hw < 2; _hw++) { \ + /* movw or movt */ \ + _opcode = _hw ? 0xe3400000 : 0xe3000000; \ + *ins++ = _opcode | (_imm16[_hw] >> 12) << 16 | \ + (reg) << 12 | (_imm16[_hw] & 0xFFF); \ + } \ +} + +#define LDR(ins, reg) \ +{ \ + *ins++ = 0xe5900000 | (reg) << 16 | (reg) << 12; \ +} + +#define BX(ins, reg) \ +{ \ + *ins++ = 0xe12fff10 | (reg); \ +} + +void trampfd_code_fill(struct trampfd *trampfd, char *addr) +{ + char *eaddr = addr + PAGE_SIZE; + int creg = trampfd->code_reg - arm_min; + int dreg = trampfd->data_reg - arm_min; + u32 *code = trampfd->code; + u32 *data = trampfd->data; + u32 *instruction = (u32 *) addr; + int i; + + for (i = 0; i < trampfd->ntrampolines; i++, code++, data++) { + /* + * movw creg, code & 0xFFFF + * movt creg, code >> 16 + */ + MOVW(instruction, creg, code); + + /* + * ldr creg, [creg] + */ + LDR(instruction, creg); + + /* + * movw dreg, data & 0xFFFF + * movt dreg, data >> 16 + */ + MOVW(instruction, dreg, data); + + /* + * ldr dreg, [dreg] + */ + LDR(instruction, dreg); + + /* + * bx creg + */ + BX(instruction, creg); + } + addr = (char *) instruction; + memset(addr, 0, eaddr - addr); +} diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl index d5cae5ffede0..85dcbc9e08ee 100644 --- a/arch/arm/tools/syscall.tbl +++ b/arch/arm/tools/syscall.tbl @@ -452,3 +452,4 @@ 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd 439 common faccessat2 sys_faccessat2 +440 common trampfd sys_trampfd -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: madvenka@linux.microsoft.com To: kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, oleg@redhat.com, x86@kernel.org, luto@kernel.org, David.Laight@ACULAB.COM, fweimer@redhat.com, mark.rutland@arm.com, mic@digikod.net, pavel@ucw.cz, madvenka@linux.microsoft.com Subject: [PATCH v2 4/4] [RFC] arm/trampfd: Provide support for the trampoline file descriptor Date: Tue, 22 Sep 2020 16:53:26 -0500 [thread overview] Message-ID: <20200922215326.4603-5-madvenka@linux.microsoft.com> (raw) In-Reply-To: <20200922215326.4603-1-madvenka@linux.microsoft.com> From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com> - Define architecture specific register names - Architecture specific functions for: - system call init - code descriptor check - data descriptor check - Fill a page with a trampoline table, Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com> --- arch/arm/include/uapi/asm/ptrace.h | 21 +++++ arch/arm/kernel/Makefile | 1 + arch/arm/kernel/trampfd.c | 124 +++++++++++++++++++++++++++++ arch/arm/tools/syscall.tbl | 1 + 4 files changed, 147 insertions(+) create mode 100644 arch/arm/kernel/trampfd.c diff --git a/arch/arm/include/uapi/asm/ptrace.h b/arch/arm/include/uapi/asm/ptrace.h index e61c65b4018d..598047768f9b 100644 --- a/arch/arm/include/uapi/asm/ptrace.h +++ b/arch/arm/include/uapi/asm/ptrace.h @@ -151,6 +151,27 @@ struct pt_regs { #define ARM_r0 uregs[0] #define ARM_ORIG_r0 uregs[17] +/* + * These register names are to be used by 32-bit applications. + */ +enum reg_32_name { + arm_min, + arm_r0 = arm_min, + arm_r1, + arm_r2, + arm_r3, + arm_r4, + arm_r5, + arm_r6, + arm_r7, + arm_r8, + arm_r9, + arm_r10, + arm_r11, + arm_r12, + arm_max, +}; + /* * The size of the user-visible VFP state as seen by PTRACE_GET/SETVFPREGS * and core dumps. diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 89e5d864e923..652c54c2f19a 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -105,5 +105,6 @@ obj-$(CONFIG_SMP) += psci_smp.o endif obj-$(CONFIG_HAVE_ARM_SMCCC) += smccc-call.o +obj-$(CONFIG_TRAMPFD) += trampfd.o extra-y := $(head-y) vmlinux.lds diff --git a/arch/arm/kernel/trampfd.c b/arch/arm/kernel/trampfd.c new file mode 100644 index 000000000000..45146ed489e8 --- /dev/null +++ b/arch/arm/kernel/trampfd.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Trampoline FD - ARM support. + * + * Author: Madhavan T. Venkataraman (madvenka@linux.microsoft.com) + * + * Copyright (c) 2020, Microsoft Corporation. + */ + +#include <linux/thread_info.h> +#include <linux/trampfd.h> + +#define TRAMPFD_CODE_SIZE 28 + +/* + * trampfd syscall. + */ +void trampfd_arch(struct trampfd_info *info) +{ + info->code_size = TRAMPFD_CODE_SIZE; + info->ntrampolines = PAGE_SIZE / info->code_size; + info->code_offset = TRAMPFD_CODE_PGOFF << PAGE_SHIFT; + info->reserved = 0; +} + +/* + * trampfd code descriptor check. + */ +int trampfd_code_arch(struct trampfd_code *code) +{ + int ntrampolines; + int min, max; + + min = arm_min; + max = arm_max; + ntrampolines = PAGE_SIZE / TRAMPFD_CODE_SIZE; + + if (code->reg < min || code->reg >= max) + return -EINVAL; + + if (!code->ntrampolines || code->ntrampolines > ntrampolines) + return -EINVAL; + return 0; +} + +/* + * trampfd data descriptor check. + */ +int trampfd_data_arch(struct trampfd_data *data) +{ + int min, max; + + min = arm_min; + max = arm_max; + + if (data->reg < min || data->reg >= max) + return -EINVAL; + return 0; +} + +#define MOVW(ins, reg, imm32) \ +{ \ + u16 *_imm16 = (u16 *) &(imm32); /* little endian */ \ + int _hw, _opcode; \ + \ + for (_hw = 0; _hw < 2; _hw++) { \ + /* movw or movt */ \ + _opcode = _hw ? 0xe3400000 : 0xe3000000; \ + *ins++ = _opcode | (_imm16[_hw] >> 12) << 16 | \ + (reg) << 12 | (_imm16[_hw] & 0xFFF); \ + } \ +} + +#define LDR(ins, reg) \ +{ \ + *ins++ = 0xe5900000 | (reg) << 16 | (reg) << 12; \ +} + +#define BX(ins, reg) \ +{ \ + *ins++ = 0xe12fff10 | (reg); \ +} + +void trampfd_code_fill(struct trampfd *trampfd, char *addr) +{ + char *eaddr = addr + PAGE_SIZE; + int creg = trampfd->code_reg - arm_min; + int dreg = trampfd->data_reg - arm_min; + u32 *code = trampfd->code; + u32 *data = trampfd->data; + u32 *instruction = (u32 *) addr; + int i; + + for (i = 0; i < trampfd->ntrampolines; i++, code++, data++) { + /* + * movw creg, code & 0xFFFF + * movt creg, code >> 16 + */ + MOVW(instruction, creg, code); + + /* + * ldr creg, [creg] + */ + LDR(instruction, creg); + + /* + * movw dreg, data & 0xFFFF + * movt dreg, data >> 16 + */ + MOVW(instruction, dreg, data); + + /* + * ldr dreg, [dreg] + */ + LDR(instruction, dreg); + + /* + * bx creg + */ + BX(instruction, creg); + } + addr = (char *) instruction; + memset(addr, 0, eaddr - addr); +} diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl index d5cae5ffede0..85dcbc9e08ee 100644 --- a/arch/arm/tools/syscall.tbl +++ b/arch/arm/tools/syscall.tbl @@ -452,3 +452,4 @@ 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd 439 common faccessat2 sys_faccessat2 +440 common trampfd sys_trampfd -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-09-22 21:53 UTC|newest] Thread overview: 111+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <210d7cd762d5307c2aa1676705b392bd445f1baa> 2020-09-16 15:08 ` [PATCH v2 0/4] [RFC] Implement Trampoline File Descriptor madvenka 2020-09-16 15:08 ` madvenka 2020-09-16 15:08 ` [PATCH v2 1/4] [RFC] fs/trampfd: Implement the trampoline file descriptor API madvenka 2020-09-16 15:08 ` madvenka 2020-09-16 15:08 ` [PATCH v2 2/4] [RFC] x86/trampfd: Provide support for the trampoline file descriptor madvenka 2020-09-16 15:08 ` madvenka 2020-09-17 1:10 ` kernel test robot 2020-09-17 3:04 ` kernel test robot 2020-09-16 15:08 ` [PATCH v2 3/4] [RFC] arm64/trampfd: " madvenka 2020-09-16 15:08 ` madvenka 2020-09-16 15:08 ` [PATCH v2 4/4] [RFC] arm/trampfd: " madvenka 2020-09-16 15:08 ` madvenka 2020-09-17 1:04 ` [PATCH v2 0/4] [RFC] Implement Trampoline File Descriptor Florian Weimer 2020-09-17 1:04 ` Florian Weimer 2020-09-17 1:04 ` Florian Weimer 2020-09-17 15:36 ` Madhavan T. Venkataraman 2020-09-17 15:36 ` Madhavan T. Venkataraman 2020-09-17 15:57 ` Madhavan T. Venkataraman 2020-09-17 15:57 ` Madhavan T. Venkataraman 2020-09-17 16:01 ` Florian Weimer 2020-09-17 16:01 ` Florian Weimer 2020-09-17 16:01 ` Florian Weimer 2020-09-23 1:46 ` Arvind Sankar 2020-09-23 1:46 ` Arvind Sankar 2020-09-23 9:11 ` Arvind Sankar 2020-09-23 9:11 ` Arvind Sankar 2020-09-23 19:17 ` Madhavan T. Venkataraman 2020-09-23 19:17 ` Madhavan T. Venkataraman 2020-09-23 19:51 ` Arvind Sankar 2020-09-23 19:51 ` Arvind Sankar 2020-09-23 23:51 ` Madhavan T. Venkataraman 2020-09-23 23:51 ` Madhavan T. Venkataraman 2020-09-24 20:23 ` Madhavan T. Venkataraman 2020-09-24 20:23 ` Madhavan T. Venkataraman 2020-09-24 20:52 ` Florian Weimer 2020-09-24 20:52 ` Florian Weimer 2020-09-24 20:52 ` Florian Weimer 2020-09-25 22:22 ` Madhavan T. Venkataraman 2020-09-25 22:22 ` Madhavan T. Venkataraman 2020-09-27 18:25 ` Madhavan T. Venkataraman 2020-09-27 18:25 ` Madhavan T. Venkataraman 2020-10-03 9:43 ` Jay K 2020-10-03 9:43 ` Jay K 2020-09-24 22:13 ` Pavel Machek 2020-09-24 22:13 ` Pavel Machek 2020-09-24 23:43 ` Arvind Sankar 2020-09-24 23:43 ` Arvind Sankar 2020-09-25 22:44 ` Madhavan T. Venkataraman 2020-09-25 22:44 ` Madhavan T. Venkataraman 2020-09-26 15:55 ` Arvind Sankar 2020-09-26 15:55 ` Arvind Sankar 2020-09-27 17:59 ` Madhavan T. Venkataraman 2020-09-27 17:59 ` Madhavan T. Venkataraman 2020-09-23 2:50 ` Jay K 2020-09-23 2:50 ` Jay K 2020-09-22 21:53 ` madvenka 2020-09-22 21:53 ` madvenka 2020-09-22 21:53 ` [PATCH v2 1/4] [RFC] fs/trampfd: Implement the trampoline file descriptor API madvenka 2020-09-22 21:53 ` madvenka 2020-09-22 21:53 ` [PATCH v2 2/4] [RFC] x86/trampfd: Provide support for the trampoline file descriptor madvenka 2020-09-22 21:53 ` madvenka 2020-09-23 13:40 ` kernel test robot 2020-09-22 21:53 ` [PATCH v2 3/4] [RFC] arm64/trampfd: " madvenka 2020-09-22 21:53 ` madvenka 2020-09-22 21:53 ` madvenka [this message] 2020-09-22 21:53 ` [PATCH v2 4/4] [RFC] arm/trampfd: " madvenka 2020-09-22 21:54 ` [PATCH v2 0/4] [RFC] Implement Trampoline File Descriptor Madhavan T. Venkataraman 2020-09-22 21:54 ` Madhavan T. Venkataraman 2020-09-23 8:14 ` Pavel Machek 2020-09-23 8:14 ` Pavel Machek 2020-09-23 9:14 ` Solar Designer 2020-09-23 9:14 ` Solar Designer 2020-09-23 14:11 ` Solar Designer 2020-09-23 14:11 ` Solar Designer 2020-09-23 15:18 ` Pavel Machek 2020-09-23 15:18 ` Pavel Machek 2020-09-23 18:00 ` Solar Designer 2020-09-23 18:00 ` Solar Designer 2020-09-23 18:21 ` Solar Designer 2020-09-23 18:21 ` Solar Designer 2020-09-23 14:39 ` Florian Weimer 2020-09-23 14:39 ` Florian Weimer 2020-09-23 14:39 ` Florian Weimer 2020-09-23 18:09 ` Andy Lutomirski 2020-09-23 18:09 ` Andy Lutomirski 2020-09-23 18:11 ` Solar Designer 2020-09-23 18:11 ` Solar Designer 2020-09-23 18:49 ` Arvind Sankar 2020-09-23 18:49 ` Arvind Sankar 2020-09-23 23:53 ` Madhavan T. Venkataraman 2020-09-23 23:53 ` Madhavan T. Venkataraman 2020-09-23 19:41 ` Madhavan T. Venkataraman 2020-09-23 19:41 ` Madhavan T. Venkataraman 2020-09-23 18:10 ` James Morris 2020-09-23 18:10 ` James Morris 2020-09-23 18:32 ` Madhavan T. Venkataraman 2020-09-23 18:32 ` Madhavan T. Venkataraman 2020-09-23 8:42 ` Pavel Machek 2020-09-23 8:42 ` Pavel Machek 2020-09-23 18:56 ` Madhavan T. Venkataraman 2020-09-23 18:56 ` Madhavan T. Venkataraman 2020-09-23 20:51 ` Pavel Machek 2020-09-23 20:51 ` Pavel Machek 2020-09-23 23:04 ` Madhavan T. Venkataraman 2020-09-23 23:04 ` Madhavan T. Venkataraman 2020-09-24 16:44 ` Mickaël Salaün 2020-09-24 16:44 ` Mickaël Salaün 2020-09-24 22:05 ` Pavel Machek 2020-09-24 22:05 ` Pavel Machek 2020-09-25 10:12 ` Mickaël Salaün 2020-09-25 10:12 ` Mickaël Salaün
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