From: Ard Biesheuvel <ardb@kernel.org> To: linux@armlinux.org.uk, linux-arm-kernel@lists.infradead.org Cc: linux-hardening@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>, Nicolas Pitre <nico@fluxnic.net>, Arnd Bergmann <arnd@arndb.de>, Kees Cook <keescook@chromium.org>, Keith Packard <keithpac@amazon.com>, Linus Walleij <linus.walleij@linaro.org>, Nick Desaulniers <ndesaulniers@google.com>, Tony Lindgren <tony@atomide.com>, Marc Zyngier <maz@kernel.org>, Vladimir Murzin <vladimir.murzin@arm.com>, Jesse Taube <mr.bossman075@gmail.com> Subject: [PATCH v5 18/32] ARM: unwind: support unwinding across multiple stacks Date: Mon, 24 Jan 2022 18:47:30 +0100 [thread overview] Message-ID: <20220124174744.1054712-19-ardb@kernel.org> (raw) In-Reply-To: <20220124174744.1054712-1-ardb@kernel.org> Implement support in the unwinder for dealing with multiple stacks. This will be needed once we add support for IRQ stacks, or for the overflow stack used by the vmap'ed stacks code. This involves tracking the unwind opcodes that either update the virtual stack pointer from another virtual register, or perform an explicit subtract on the virtual stack pointer, and updating the low and high bounds that we use to sanitize the stack pointer accordingly. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Keith Packard <keithpac@amazon.com> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M --- arch/arm/kernel/unwind.c | 25 +++++++++++++------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c index 59fdf257bf8b..9cb9af3fc433 100644 --- a/arch/arm/kernel/unwind.c +++ b/arch/arm/kernel/unwind.c @@ -52,6 +52,7 @@ EXPORT_SYMBOL(__aeabi_unwind_cpp_pr2); struct unwind_ctrl_block { unsigned long vrs[16]; /* virtual register set */ const unsigned long *insn; /* pointer to the current instructions word */ + unsigned long sp_low; /* lowest value of sp allowed */ unsigned long sp_high; /* highest value of sp allowed */ /* * 1 : check for stack overflow for each register pop. @@ -256,8 +257,12 @@ static int unwind_exec_pop_subset_r4_to_r13(struct unwind_ctrl_block *ctrl, mask >>= 1; reg++; } - if (!load_sp) + if (!load_sp) { ctrl->vrs[SP] = (unsigned long)vsp; + } else { + ctrl->sp_low = ctrl->vrs[SP]; + ctrl->sp_high = ALIGN(ctrl->sp_low, THREAD_SIZE); + } return URC_OK; } @@ -313,9 +318,10 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl) if ((insn & 0xc0) == 0x00) ctrl->vrs[SP] += ((insn & 0x3f) << 2) + 4; - else if ((insn & 0xc0) == 0x40) + else if ((insn & 0xc0) == 0x40) { ctrl->vrs[SP] -= ((insn & 0x3f) << 2) + 4; - else if ((insn & 0xf0) == 0x80) { + ctrl->sp_low = ctrl->vrs[SP]; + } else if ((insn & 0xf0) == 0x80) { unsigned long mask; insn = (insn << 8) | unwind_get_byte(ctrl); @@ -330,9 +336,11 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl) if (ret) goto error; } else if ((insn & 0xf0) == 0x90 && - (insn & 0x0d) != 0x0d) + (insn & 0x0d) != 0x0d) { ctrl->vrs[SP] = ctrl->vrs[insn & 0x0f]; - else if ((insn & 0xf0) == 0xa0) { + ctrl->sp_low = ctrl->vrs[SP]; + ctrl->sp_high = ALIGN(ctrl->sp_low, THREAD_SIZE); + } else if ((insn & 0xf0) == 0xa0) { ret = unwind_exec_pop_r4_to_rN(ctrl, insn); if (ret) goto error; @@ -375,13 +383,12 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl) */ int unwind_frame(struct stackframe *frame) { - unsigned long low; const struct unwind_idx *idx; struct unwind_ctrl_block ctrl; /* store the highest address on the stack to avoid crossing it*/ - low = frame->sp; - ctrl.sp_high = ALIGN(low, THREAD_SIZE); + ctrl.sp_low = frame->sp; + ctrl.sp_high = ALIGN(ctrl.sp_low, THREAD_SIZE); pr_debug("%s(pc = %08lx lr = %08lx sp = %08lx)\n", __func__, frame->pc, frame->lr, frame->sp); @@ -437,7 +444,7 @@ int unwind_frame(struct stackframe *frame) urc = unwind_exec_insn(&ctrl); if (urc < 0) return urc; - if (ctrl.vrs[SP] < low || ctrl.vrs[SP] >= ctrl.sp_high) + if (ctrl.vrs[SP] < ctrl.sp_low || ctrl.vrs[SP] > ctrl.sp_high) return -URC_FAILURE; } -- 2.30.2
WARNING: multiple messages have this Message-ID (diff)
From: Ard Biesheuvel <ardb@kernel.org> To: linux@armlinux.org.uk, linux-arm-kernel@lists.infradead.org Cc: linux-hardening@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>, Nicolas Pitre <nico@fluxnic.net>, Arnd Bergmann <arnd@arndb.de>, Kees Cook <keescook@chromium.org>, Keith Packard <keithpac@amazon.com>, Linus Walleij <linus.walleij@linaro.org>, Nick Desaulniers <ndesaulniers@google.com>, Tony Lindgren <tony@atomide.com>, Marc Zyngier <maz@kernel.org>, Vladimir Murzin <vladimir.murzin@arm.com>, Jesse Taube <mr.bossman075@gmail.com> Subject: [PATCH v5 18/32] ARM: unwind: support unwinding across multiple stacks Date: Mon, 24 Jan 2022 18:47:30 +0100 [thread overview] Message-ID: <20220124174744.1054712-19-ardb@kernel.org> (raw) In-Reply-To: <20220124174744.1054712-1-ardb@kernel.org> Implement support in the unwinder for dealing with multiple stacks. This will be needed once we add support for IRQ stacks, or for the overflow stack used by the vmap'ed stacks code. This involves tracking the unwind opcodes that either update the virtual stack pointer from another virtual register, or perform an explicit subtract on the virtual stack pointer, and updating the low and high bounds that we use to sanitize the stack pointer accordingly. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Keith Packard <keithpac@amazon.com> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M --- arch/arm/kernel/unwind.c | 25 +++++++++++++------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c index 59fdf257bf8b..9cb9af3fc433 100644 --- a/arch/arm/kernel/unwind.c +++ b/arch/arm/kernel/unwind.c @@ -52,6 +52,7 @@ EXPORT_SYMBOL(__aeabi_unwind_cpp_pr2); struct unwind_ctrl_block { unsigned long vrs[16]; /* virtual register set */ const unsigned long *insn; /* pointer to the current instructions word */ + unsigned long sp_low; /* lowest value of sp allowed */ unsigned long sp_high; /* highest value of sp allowed */ /* * 1 : check for stack overflow for each register pop. @@ -256,8 +257,12 @@ static int unwind_exec_pop_subset_r4_to_r13(struct unwind_ctrl_block *ctrl, mask >>= 1; reg++; } - if (!load_sp) + if (!load_sp) { ctrl->vrs[SP] = (unsigned long)vsp; + } else { + ctrl->sp_low = ctrl->vrs[SP]; + ctrl->sp_high = ALIGN(ctrl->sp_low, THREAD_SIZE); + } return URC_OK; } @@ -313,9 +318,10 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl) if ((insn & 0xc0) == 0x00) ctrl->vrs[SP] += ((insn & 0x3f) << 2) + 4; - else if ((insn & 0xc0) == 0x40) + else if ((insn & 0xc0) == 0x40) { ctrl->vrs[SP] -= ((insn & 0x3f) << 2) + 4; - else if ((insn & 0xf0) == 0x80) { + ctrl->sp_low = ctrl->vrs[SP]; + } else if ((insn & 0xf0) == 0x80) { unsigned long mask; insn = (insn << 8) | unwind_get_byte(ctrl); @@ -330,9 +336,11 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl) if (ret) goto error; } else if ((insn & 0xf0) == 0x90 && - (insn & 0x0d) != 0x0d) + (insn & 0x0d) != 0x0d) { ctrl->vrs[SP] = ctrl->vrs[insn & 0x0f]; - else if ((insn & 0xf0) == 0xa0) { + ctrl->sp_low = ctrl->vrs[SP]; + ctrl->sp_high = ALIGN(ctrl->sp_low, THREAD_SIZE); + } else if ((insn & 0xf0) == 0xa0) { ret = unwind_exec_pop_r4_to_rN(ctrl, insn); if (ret) goto error; @@ -375,13 +383,12 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl) */ int unwind_frame(struct stackframe *frame) { - unsigned long low; const struct unwind_idx *idx; struct unwind_ctrl_block ctrl; /* store the highest address on the stack to avoid crossing it*/ - low = frame->sp; - ctrl.sp_high = ALIGN(low, THREAD_SIZE); + ctrl.sp_low = frame->sp; + ctrl.sp_high = ALIGN(ctrl.sp_low, THREAD_SIZE); pr_debug("%s(pc = %08lx lr = %08lx sp = %08lx)\n", __func__, frame->pc, frame->lr, frame->sp); @@ -437,7 +444,7 @@ int unwind_frame(struct stackframe *frame) urc = unwind_exec_insn(&ctrl); if (urc < 0) return urc; - if (ctrl.vrs[SP] < low || ctrl.vrs[SP] >= ctrl.sp_high) + if (ctrl.vrs[SP] < ctrl.sp_low || ctrl.vrs[SP] > ctrl.sp_high) return -URC_FAILURE; } -- 2.30.2 _______________________________________________ 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:[~2022-01-24 17:48 UTC|newest] Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-01-24 17:47 [PATCH v5 00/32] ARM vmap'ed and IRQ stacks roundup Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 01/32] ARM: riscpc: drop support for IOMD_IRQREQC/IOMD_IRQREQD IRQ groups Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 02/32] ARM: riscpc: use GENERIC_IRQ_MULTI_HANDLER Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 03/32] ARM: footbridge: " Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 04/32] ARM: iop32x: offset IRQ numbers by 1 Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 05/32] ARM: iop32x: use GENERIC_IRQ_MULTI_HANDLER Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 06/32] ARM: remove old-style irq entry Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 07/32] irqchip: nvic: Use GENERIC_IRQ_MULTI_HANDLER Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 08/32] ARM: decompressor: disable stack protector Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 09/32] ARM: stackprotector: prefer compiler for TLS based per-task protector Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 10/32] ARM: entry: preserve thread_info pointer in switch_to Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 11/32] ARM: module: implement support for PC-relative group relocations Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 12/32] ARM: assembler: add optimized ldr/str macros to load variables from memory Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 13/32] ARM: percpu: add SMP_ON_UP support Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 14/32] ARM: use TLS register for 'current' on !SMP as well Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 15/32] ARM: smp: defer TPIDRURO update for SMP v6 configurations too Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 16/32] ARM: implement THREAD_INFO_IN_TASK for uniprocessor systems Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 17/32] ARM: assembler: introduce bl_r macro Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel [this message] 2022-01-24 17:47 ` [PATCH v5 18/32] ARM: unwind: support unwinding across multiple stacks Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 19/32] ARM: export dump_mem() to other objects Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 20/32] ARM: unwind: dump exception stack from calling frame Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 21/32] ARM: backtrace-clang: avoid crash on bogus frame pointer Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 22/32] ARM: implement IRQ stacks Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 23/32] ARM: call_with_stack: add unwind support Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 24/32] ARM: run softirqs on the per-CPU IRQ stack Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-03-22 9:04 ` Sebastian Andrzej Siewior 2022-03-22 9:04 ` Sebastian Andrzej Siewior 2022-03-22 9:35 ` Ard Biesheuvel 2022-03-22 9:35 ` Ard Biesheuvel 2022-03-22 11:29 ` Sebastian Andrzej Siewior 2022-03-22 11:29 ` Sebastian Andrzej Siewior 2022-01-24 17:47 ` [PATCH v5 25/32] ARM: memcpy: use frame pointer as unwind anchor Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 26/32] ARM: memmove: " Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 27/32] ARM: memset: clean up unwind annotations Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 28/32] ARM: unwind: disregard unwind info before stack frame is set up Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 29/32] ARM: entry: rework stack realignment code in svc_entry Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 30/32] ARM: switch_to: clean up Thumb2 code path Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 31/32] ARM: mm: prepare vmalloc_seq handling for use under SMP Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:47 ` [PATCH v5 32/32] ARM: implement support for vmap'ed stacks Ard Biesheuvel 2022-01-24 17:47 ` Ard Biesheuvel 2022-01-24 17:56 ` [PATCH v5 00/32] ARM vmap'ed and IRQ stacks roundup Russell King (Oracle) 2022-01-24 17:56 ` Russell King (Oracle) 2022-01-24 17:57 ` Ard Biesheuvel 2022-01-24 17:57 ` Ard Biesheuvel
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