From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by 2002:a19:f807:0:0:0:0:0 with SMTP id a7csp1856699lff; Fri, 18 Jun 2021 12:29:56 -0700 (PDT) X-Received: by 2002:a65:6a16:: with SMTP id m22mr11651094pgu.29.1624044596119; Fri, 18 Jun 2021 12:29:56 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1624044596; cv=none; d=google.com; s=arc-20160816; b=uWxpZTiJQRhKqcEuh+szdaikI0ZMQYSza5UjFg1qDTpCghmidDVJho1S06aRLg57l6 xxwjFlxS7q/3Cr6RMyDcLy5w38yN//rET5H8z9toX6Aew52wZYoBUSwEnwTJjM7mGXTx FLfjuaQnT2gXopFnk/BW3fO6Cxgvc13FDMe5pl0APQmBCBSBeoiXNBqWvt/QOudK7Zow IjxQljHA+bimBiHlUlkrib9UVy8/cB9vx04ITB2MsNzWlwjR+ajomMeDMiy6tF2F349z IibPY9RWWjnVbqagGhrOw1R0oY56q+OqhOmZRSLa//QkTe0Cz4iqbNqq8oJGy7c+Am4+ ZEPA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:dkim-signature; bh=BNQDUVyR3ttAl/s4i0xlO2IvPvq1tkDghI/KxgsvylI=; b=KuPHa1MXypu1+oRneUIOd8bFk85/9rQQSq5Pusb9SYmRD2m66MbQ4qQ/mFn56w5ZFP aCCoOE/p8eHetRXw+LO2KwZ4qwGN2wXjVI9bso5HdyYliSidX2Pe42Ju5xG+OXxgbG7G p72h8F6PrO6LSBtfLVN7ytc2kwtiXZFQxklxWzoubonOdxM1nDGLBSqA8SahA+4JNVgX XPyJMHppl4h0CQFFf0qBW2T/IWnOacpw8/4qzJXZtkuvVk9/A4MsQHgY9hVW7Fhr4x3W yDp2I7i9poN+nUQGzdkPh8gqsCsg1lXmAHcFV3XvG30TKgTMRaDWIMROhFtk3KErkgNp l9NQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=AC1CWAdQ; spf=pass (google.com: domain of richard.henderson@linaro.org designates 209.85.220.41 as permitted sender) smtp.mailfrom=richard.henderson@linaro.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id k23sor5346704pls.73.2021.06.18.12.29.55 for (Google Transport Security); Fri, 18 Jun 2021 12:29:56 -0700 (PDT) Received-SPF: pass (google.com: domain of richard.henderson@linaro.org designates 209.85.220.41 as permitted sender) client-ip=209.85.220.41; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=AC1CWAdQ; spf=pass (google.com: domain of richard.henderson@linaro.org designates 209.85.220.41 as permitted sender) smtp.mailfrom=richard.henderson@linaro.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=BNQDUVyR3ttAl/s4i0xlO2IvPvq1tkDghI/KxgsvylI=; b=AC1CWAdQvfJEvLg1Akyz7PpKMSo5AtgvImyYJq9b8w9PNfynfZJnTqke3HXHaRPrhm HNM9VOzfKu7/ZkIYCb0VQDNnbCuKEtbgxZqbrCDvTOaXNDAmAeyEhasYaGvZaKYPAMYa DXMl+NdhCPqP3pKl4HhzBhIyj3aCfKVeRhQMYKAv+vjKNtO9IfVfoocSAqQTg3PnK6h6 Rom33ECpxZW8e9N9XVxFFzjYMtSvQN/bj8JXfR3fzAxZQS0YNy6e3t8/cBL8ZJdInTkV vOgvmtMsYw3sgB4X0rOxRt81GCtmb7Cxq8HNv2qNBp4XR7txBM45nPRmXPhQ9a/c2AjO sIMQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=BNQDUVyR3ttAl/s4i0xlO2IvPvq1tkDghI/KxgsvylI=; b=dQ1lQIC38e37p8NIVZuGZtdAdOYUjpUxu2LtxLsqCR0o67Uz0UCr4dj0nHrNftMFyh ffItB17OmKFm5k/AQpyjoljGGQWawbUqW66B0H9vXYpP/L8qjKqbgEuLSIyrekNi4yhu vk0HpuLI4ptsLNwDEaKQYNtqITbiOb3MXoSj2/TRTFiDfhiq05gkzfMEzYFswX+rJpBq yEnKY478oolv2GyShkjzRoqSPXNa7sD5DvaBCQofYPEZuJ1HlguRR0VTOp2PWhoAaVS9 RU5bl1dGkgC+Ts8ZOlLde/y2JwVULMEloD19CHTCopNKBsSl7DfSPWmDkjoEsZb/q6pe uFDw== X-Gm-Message-State: AOAM533VnsEJLZsHI6YlgK9gT7C/oXpMpnv12APeXjM/j9yW8Caev+Oa G87dmpMolZ0gGdzlCafFGpGiCJOW X-Google-Smtp-Source: ABdhPJx4EZCjuWDopqawF6ieZS7OMH1OO355kYq36I4GWGQatiDkEQDynD29XHD++yTJ6o2q7m/yQQ== X-Received: by 2002:a17:902:788d:b029:11f:6a5d:d5e2 with SMTP id q13-20020a170902788db029011f6a5dd5e2mr6264138pll.16.1624044595256; Fri, 18 Jun 2021 12:29:55 -0700 (PDT) Return-Path: Received: from localhost.localdomain ([71.212.149.176]) by smtp.gmail.com with ESMTPSA id 92sm11938234pjv.29.2021.06.18.12.29.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 18 Jun 2021 12:29:55 -0700 (PDT) From: Richard Henderson To: qemu-devel@nongnu.org Cc: laurent@vivier.eu, alex.bennee@linaro.org, qemu-arm@nongnu.org Subject: [PATCH v2 05/23] linux-user/arm: Implement setup_sigtramp Date: Fri, 18 Jun 2021 12:29:33 -0700 Message-Id: <20210618192951.125651-6-richard.henderson@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210618192951.125651-1-richard.henderson@linaro.org> References: <20210618192951.125651-1-richard.henderson@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TUID: yHKLZYBQjZAV ARM is more complicated than the others, in that we also have trampolines for using SA_RESTORER with FDPIC, and we need to create trampolines for both ARM and Thumb modes. Cc: qemu-arm@nongnu.org Signed-off-by: Richard Henderson --- linux-user/arm/target_signal.h | 2 + linux-user/arm/signal.c | 170 +++++++++++++++++++-------------- 2 files changed, 100 insertions(+), 72 deletions(-) diff --git a/linux-user/arm/target_signal.h b/linux-user/arm/target_signal.h index 0998dd6dfa..1e7fb0cecb 100644 --- a/linux-user/arm/target_signal.h +++ b/linux-user/arm/target_signal.h @@ -22,4 +22,6 @@ typedef struct target_sigaltstack { #include "../generic/signal.h" #define TARGET_ARCH_HAS_SETUP_FRAME +#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 1 + #endif /* ARM_TARGET_SIGNAL_H */ diff --git a/linux-user/arm/signal.c b/linux-user/arm/signal.c index 2d30345fc2..63bdd59ab9 100644 --- a/linux-user/arm/signal.c +++ b/linux-user/arm/signal.c @@ -101,13 +101,12 @@ struct sigframe_v1 { struct target_sigcontext sc; abi_ulong extramask[TARGET_NSIG_WORDS-1]; - abi_ulong retcode[4]; }; struct sigframe_v2 { struct target_ucontext_v2 uc; - abi_ulong retcode[4]; + abi_ulong fdpic_ret; }; struct rt_sigframe_v1 @@ -116,49 +115,20 @@ struct rt_sigframe_v1 abi_ulong puc; struct target_siginfo info; struct target_ucontext_v1 uc; - abi_ulong retcode[4]; }; struct rt_sigframe_v2 { struct target_siginfo info; struct target_ucontext_v2 uc; - abi_ulong retcode[4]; + abi_ulong fdpic_ret; }; /* - * For ARM syscalls, we encode the syscall number into the instruction. + * Stubs needed to make sure the FD register (r9) contains the right value. + * There are 4 of them, each consuming 8 bytes. */ -#define SWI_SYS_SIGRETURN (0xef000000|(TARGET_NR_sigreturn + ARM_SYSCALL_BASE)) -#define SWI_SYS_RT_SIGRETURN (0xef000000|(TARGET_NR_rt_sigreturn + ARM_SYSCALL_BASE)) - -/* - * For Thumb syscalls, we pass the syscall number via r7. We therefore - * need two 16-bit instructions. - */ -#define SWI_THUMB_SIGRETURN (0xdf00 << 16 | 0x2700 | (TARGET_NR_sigreturn)) -#define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 | 0x2700 | (TARGET_NR_rt_sigreturn)) - -static const abi_ulong retcodes[4] = { - SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN, - SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN -}; - -/* - * Stub needed to make sure the FD register (r9) contains the right - * value. - */ -static const unsigned long sigreturn_fdpic_codes[3] = { - 0xe59fc004, /* ldr r12, [pc, #4] to read function descriptor */ - 0xe59c9004, /* ldr r9, [r12, #4] to setup GOT */ - 0xe59cf000 /* ldr pc, [r12] to jump into restorer */ -}; - -static const unsigned long sigreturn_fdpic_thumb_codes[3] = { - 0xc008f8df, /* ldr r12, [pc, #8] to read function descriptor */ - 0x9004f8dc, /* ldr r9, [r12, #4] to setup GOT */ - 0xf000f8dc /* ldr pc, [r12] to jump into restorer */ -}; +static abi_ulong sigreturn_fdpic_tramp; static inline int valid_user_regs(CPUARMState *regs) { @@ -219,13 +189,12 @@ get_sigframe(struct target_sigaction *ka, CPUARMState *regs, int framesize) static int setup_return(CPUARMState *env, struct target_sigaction *ka, - abi_ulong *rc, abi_ulong frame_addr, int usig, abi_ulong rc_addr) + abi_ulong frame_addr, int usig) { abi_ulong handler = 0; abi_ulong handler_fdpic_GOT = 0; abi_ulong retcode; - - int thumb; + int thumb, retcode_idx; int is_fdpic = info_is_fdpic(((TaskState *)thread_cpu->opaque)->info); if (is_fdpic) { @@ -243,6 +212,7 @@ setup_return(CPUARMState *env, struct target_sigaction *ka, } thumb = handler & 1; + retcode_idx = thumb + (ka->sa_flags & TARGET_SA_SIGINFO ? 2 : 0); uint32_t cpsr = cpsr_read(env); @@ -260,37 +230,24 @@ setup_return(CPUARMState *env, struct target_sigaction *ka, if (ka->sa_flags & TARGET_SA_RESTORER) { if (is_fdpic) { - /* For FDPIC we ensure that the restorer is called with a - * correct r9 value. For that we need to write code on - * the stack that sets r9 and jumps back to restorer - * value. + /* + * For FDPIC we ensure that the restorer is called with a + * correct r9 value. For that we use a special trampoline + * that reads the function descriptor from the frame, + * sets r9 and jumps back to restorer value. */ - if (thumb) { - __put_user(sigreturn_fdpic_thumb_codes[0], rc); - __put_user(sigreturn_fdpic_thumb_codes[1], rc + 1); - __put_user(sigreturn_fdpic_thumb_codes[2], rc + 2); - __put_user((abi_ulong)ka->sa_restorer, rc + 3); - } else { - __put_user(sigreturn_fdpic_codes[0], rc); - __put_user(sigreturn_fdpic_codes[1], rc + 1); - __put_user(sigreturn_fdpic_codes[2], rc + 2); - __put_user((abi_ulong)ka->sa_restorer, rc + 3); - } - - retcode = rc_addr + thumb; + abi_ulong fd_ofs = (retcode_idx & 2 + ? offsetof(struct rt_sigframe_v2, fdpic_ret) + : offsetof(struct sigframe_v2, fdpic_ret)); + put_user_ual(ka->sa_restorer, frame_addr + fd_ofs); + /* Each trampoline variant consumes 8-byte slot. */ + retcode = sigreturn_fdpic_tramp + retcode_idx * 8 + thumb; } else { retcode = ka->sa_restorer; } } else { - unsigned int idx = thumb; - - if (ka->sa_flags & TARGET_SA_SIGINFO) { - idx += 2; - } - - __put_user(retcodes[idx], rc); - - retcode = rc_addr + thumb; + /* Each trampoline variant consumes one 4-byte slot. */ + retcode = default_sigreturn + retcode_idx * 4 + thumb; } env->regs[0] = usig; @@ -394,8 +351,7 @@ static void setup_frame_v1(int usig, struct target_sigaction *ka, __put_user(set->sig[i], &frame->extramask[i - 1]); } - if (setup_return(regs, ka, frame->retcode, frame_addr, usig, - frame_addr + offsetof(struct sigframe_v1, retcode))) { + if (setup_return(regs, ka, frame_addr, usig)) { goto sigsegv; } @@ -419,8 +375,7 @@ static void setup_frame_v2(int usig, struct target_sigaction *ka, setup_sigframe_v2(&frame->uc, set, regs); - if (setup_return(regs, ka, frame->retcode, frame_addr, usig, - frame_addr + offsetof(struct sigframe_v2, retcode))) { + if (setup_return(regs, ka, frame_addr, usig)) { goto sigsegv; } @@ -475,8 +430,7 @@ static void setup_rt_frame_v1(int usig, struct target_sigaction *ka, __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]); } - if (setup_return(env, ka, frame->retcode, frame_addr, usig, - frame_addr + offsetof(struct rt_sigframe_v1, retcode))) { + if (setup_return(env, ka, frame_addr, usig)) { goto sigsegv; } @@ -509,8 +463,7 @@ static void setup_rt_frame_v2(int usig, struct target_sigaction *ka, setup_sigframe_v2(&frame->uc, set, env); - if (setup_return(env, ka, frame->retcode, frame_addr, usig, - frame_addr + offsetof(struct rt_sigframe_v2, retcode))) { + if (setup_return(env, ka, frame_addr, usig)) { goto sigsegv; } @@ -841,3 +794,76 @@ long do_rt_sigreturn(CPUARMState *env) return do_rt_sigreturn_v1(env); } } + +void setup_sigtramp(abi_ulong sigtramp_page) +{ + enum { + /* For ARM, we encode the syscall number into the instruction. */ + SWI_SYS_SIGRETURN = + 0xef000000 | (TARGET_NR_sigreturn + ARM_SYSCALL_BASE), + SWI_SYS_RT_SIGRETURN = + 0xef000000 | (TARGET_NR_rt_sigreturn + ARM_SYSCALL_BASE), + + /* + * For Thumb , we pass the syscall number via r7. + * We therefore need two 16-bit instructions. + */ + SWI_THUMB_SIGRETURN = + 0xdf00 << 16 | 0x2700 | TARGET_NR_sigreturn, + SWI_THUMB_RT_SIGRETURN = + 0xdf00 << 16 | 0x2700 | TARGET_NR_rt_sigreturn, + + SIGFRAME_FDPIC_OFS = offsetof(struct sigframe_v2, fdpic_ret), + RT_SIGFRAME_FDPIC_OFS = offsetof(struct rt_sigframe_v2, fdpic_ret), + }; + + uint32_t total_size = 4 * 4 + 2 * 8; + uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, total_size, 0); + uint32_t i = 0; + + assert(tramp != NULL); + + default_sigreturn = sigtramp_page; + __put_user(SWI_SYS_SIGRETURN, &tramp[i++]); + __put_user(SWI_THUMB_SIGRETURN, &tramp[i++]); + __put_user(SWI_SYS_RT_SIGRETURN, &tramp[i++]); + __put_user(SWI_THUMB_RT_SIGRETURN, &tramp[i++]); + + /* + * FDPIC require trampolines to call sa_restorer. + * + * ARM versions use: + * ldr r9, [sp, #ofs] + * ldmia r9, {r9, pc} + * + * Thumb versions use: + * ldrd r9, r10, [sp, #ofs] + * bx r10 + * nop + */ + sigreturn_fdpic_tramp = sigtramp_page + i * 4; + + /* ARM sigframe */ + QEMU_BUILD_BUG_ON(SIGFRAME_FDPIC_OFS > 0xfff); + __put_user(0xe59d9000 | SIGFRAME_FDPIC_OFS, &tramp[i++]); + __put_user(0xe8998200, &tramp[i++]); + + /* Thumb sigframe */ + QEMU_BUILD_BUG_ON(SIGFRAME_FDPIC_OFS > 0xff << 2); + QEMU_BUILD_BUG_ON(SIGFRAME_FDPIC_OFS & 3); + __put_user(0x9a00e9dd | (SIGFRAME_FDPIC_OFS << 14), &tramp[i++]); + __put_user(0x46c04750, &tramp[i++]); + + /* ARM rt_sigframe */ + QEMU_BUILD_BUG_ON(RT_SIGFRAME_FDPIC_OFS > 0xfff); + __put_user(0xe59d9000 | RT_SIGFRAME_FDPIC_OFS, &tramp[i++]); + __put_user(0xe8998200, &tramp[i++]); + + /* Thumb rt_sigframe */ + QEMU_BUILD_BUG_ON(RT_SIGFRAME_FDPIC_OFS > 0xff << 2); + QEMU_BUILD_BUG_ON(RT_SIGFRAME_FDPIC_OFS & 3); + __put_user(0x9a00e9dd | (RT_SIGFRAME_FDPIC_OFS << 14), &tramp[i++]); + __put_user(0x46c04750, &tramp[i++]); + + unlock_user(tramp, sigtramp_page, total_size); +} -- 2.25.1