From c658eac628aa8df040dfe614556d95e6da3a9ffb Mon Sep 17 00:00:00 2001 From: Chris Zankel Date: Tue, 12 Feb 2008 13:17:07 -0800 Subject: [XTENSA] Add support for configurable registers and coprocessors The Xtensa architecture allows to define custom instructions and registers. Registers that are bound to a coprocessor are only accessible if the corresponding enable bit is set, which allows to implement a 'lazy' context switch mechanism. Other registers needs to be saved and restore at the time of the context switch or during interrupt handling. This patch adds support for these additional states: - save and restore registers that are used by the compiler upon interrupt entry and exit. - context switch additional registers unbound to any coprocessor - 'lazy' context switch of registers bound to a coprocessor - ptrace interface to provide access to additional registers - update configuration files in include/asm-xtensa/variant-fsf Signed-off-by: Chris Zankel --- arch/xtensa/kernel/ptrace.c | 347 +++++++++++++++++++++++--------------------- 1 file changed, 184 insertions(+), 163 deletions(-) (limited to 'arch/xtensa/kernel/ptrace.c') diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c index 5533c7850d53..f6669d605125 100644 --- a/arch/xtensa/kernel/ptrace.c +++ b/arch/xtensa/kernel/ptrace.c @@ -4,7 +4,7 @@ * License. See the file "COPYING" in the main directory of this archive * for more details. * - * Copyright (C) 2001 - 2005 Tensilica Inc. + * Copyright (C) 2001 - 2007 Tensilica Inc. * * Joe Taylor * Chris Zankel @@ -28,14 +28,10 @@ #include #include #include - -#define TEST_KERNEL // verify kernel operations FIXME: remove - +#include /* - * Called by kernel/ptrace.c when detaching.. - * - * Make sure single step bits etc are not set. + * Called by kernel/ptrace.c when detaching to disable single stepping. */ void ptrace_disable(struct task_struct *child) @@ -43,136 +39,233 @@ void ptrace_disable(struct task_struct *child) /* Nothing to do.. */ } -long arch_ptrace(struct task_struct *child, long request, long addr, long data) +int ptrace_getregs(struct task_struct *child, void __user *uregs) { - int ret = -EPERM; + struct pt_regs *regs = task_pt_regs(child); + xtensa_gregset_t __user *gregset = uregs; + unsigned long wb = regs->windowbase; + unsigned long ws = regs->windowstart; + unsigned long wm = regs->wmask; + int ret = 0; + int live, last; + + if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t))) + return -EIO; + + /* Norm windowstart to a windowbase of 0. */ + + ws = ((ws>>wb) | (ws<<(WSBITS-wb))) & ((1<pc, &gregset->pc); + ret |= __put_user(regs->ps & ~(1 << PS_EXCM_BIT), &gregset->ps); + ret |= __put_user(regs->lbeg, &gregset->lbeg); + ret |= __put_user(regs->lend, &gregset->lend); + ret |= __put_user(regs->lcount, &gregset->lcount); + ret |= __put_user(ws, &gregset->windowstart); + + live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16; + last = XCHAL_NUM_AREGS - (wm >> 4) * 4; + ret |= __copy_to_user(gregset->a, regs->areg, live * 4); + ret |= __copy_to_user(gregset->a + last, regs->areg + last, (wm>>4)*16); + + return ret ? -EFAULT : 0; +} - switch (request) { - case PTRACE_PEEKTEXT: /* read word at location addr. */ - case PTRACE_PEEKDATA: - ret = generic_ptrace_peekdata(child, addr, data); - goto out; +int ptrace_setregs(struct task_struct *child, void __user *uregs) +{ + struct pt_regs *regs = task_pt_regs(child); + xtensa_gregset_t *gregset = uregs; + const unsigned long ps_mask = PS_CALLINC_MASK | PS_OWB_MASK; + unsigned long wm = regs->wmask; + unsigned long ps; + int ret = 0; + int live, last; + + if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t))) + return -EIO; + + ret |= __get_user(regs->pc, &gregset->pc); + ret |= __get_user(ps, &gregset->ps); + ret |= __get_user(regs->lbeg, &gregset->lbeg); + ret |= __get_user(regs->lend, &gregset->lend); + ret |= __get_user(regs->lcount, &gregset->lcount); + + regs->ps = (regs->ps & ~ps_mask) | (ps & ps_mask) | (1 << PS_EXCM_BIT); + + live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16; + last = XCHAL_NUM_AREGS - (wm >> 4) * 4; + ret |= __copy_from_user(regs->areg, gregset->a, live * 4); + ret |= __copy_from_user(regs->areg+last, gregset->a+last, (wm>>4)*16); + + return ret ? -EFAULT : 0; +} - /* Read the word at location addr in the USER area. */ - case PTRACE_PEEKUSR: - { - struct pt_regs *regs; - unsigned long tmp; +int ptrace_getxregs(struct task_struct *child, void __user *uregs) +{ + struct pt_regs *regs = task_pt_regs(child); + struct thread_info *ti = task_thread_info(child); + elf_xtregs_t __user *xtregs = uregs; + int ret = 0; + + if (!access_ok(VERIFY_WRITE, uregs, sizeof(elf_xtregs_t))) + return -EIO; + +#if XTENSA_HAVE_COPROCESSORS + /* Flush all coprocessor registers to memory. */ + coprocessor_flush_all(ti); + ret |= __copy_to_user(&xtregs->cp0, &ti->xtregs_cp, + sizeof(xtregs_coprocessor_t)); +#endif + ret |= __copy_to_user(&xtregs->opt, ®s->xtregs_opt, + sizeof(xtregs->opt)); + ret |= __copy_to_user(&xtregs->user,&ti->xtregs_user, + sizeof(xtregs->user)); - regs = task_pt_regs(child); - tmp = 0; /* Default return value. */ + return ret ? -EFAULT : 0; +} + +int ptrace_setxregs(struct task_struct *child, void __user *uregs) +{ + struct thread_info *ti = task_thread_info(child); + struct pt_regs *regs = task_pt_regs(child); + elf_xtregs_t *xtregs = uregs; + int ret = 0; + +#if XTENSA_HAVE_COPROCESSORS + /* Flush all coprocessors before we overwrite them. */ + coprocessor_flush_all(ti); + coprocessor_release_all(ti); + + ret |= __copy_from_user(&ti->xtregs_cp, &xtregs->cp0, + sizeof(xtregs_coprocessor_t)); +#endif + ret |= __copy_from_user(®s->xtregs_opt, &xtregs->opt, + sizeof(xtregs->opt)); + ret |= __copy_from_user(&ti->xtregs_user, &xtregs->user, + sizeof(xtregs->user)); + + return ret ? -EFAULT : 0; +} + +int ptrace_peekusr(struct task_struct *child, long regno, long __user *ret) +{ + struct pt_regs *regs; + unsigned long tmp; + + regs = task_pt_regs(child); + tmp = 0; /* Default return value. */ - switch(addr) { + switch(regno) { case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1: - { - int ar = addr - REG_AR_BASE - regs->windowbase * 4; - ar &= (XCHAL_NUM_AREGS - 1); - if (ar < 16 && ar + (regs->wmask >> 4) * 4 >= 0) - tmp = regs->areg[ar]; - else - ret = -EIO; + tmp = regs->areg[regno - REG_AR_BASE]; break; - } + case REG_A_BASE ... REG_A_BASE + 15: - tmp = regs->areg[addr - REG_A_BASE]; + tmp = regs->areg[regno - REG_A_BASE]; break; + case REG_PC: tmp = regs->pc; break; + case REG_PS: /* Note: PS.EXCM is not set while user task is running; * its being set in regs is for exception handling * convenience. */ tmp = (regs->ps & ~(1 << PS_EXCM_BIT)); break; + case REG_WB: - tmp = regs->windowbase; - break; + break; /* tmp = 0 */ + case REG_WS: - tmp = regs->windowstart; + { + unsigned long wb = regs->windowbase; + unsigned long ws = regs->windowstart; + tmp = ((ws>>wb) | (ws<<(WSBITS-wb))) & ((1<lbeg; break; + case REG_LEND: tmp = regs->lend; break; + case REG_LCOUNT: tmp = regs->lcount; break; + case REG_SAR: tmp = regs->sar; break; - case REG_DEPC: - tmp = regs->depc; - break; - case REG_EXCCAUSE: - tmp = regs->exccause; - break; - case REG_EXCVADDR: - tmp = regs->excvaddr; - break; + case SYSCALL_NR: tmp = regs->syscall; break; - default: - tmp = 0; - ret = -EIO; - goto out; - } - ret = put_user(tmp, (unsigned long *) data); - goto out; - } - case PTRACE_POKETEXT: /* write the word at location addr. */ - case PTRACE_POKEDATA: - ret = generic_ptrace_pokedata(child, addr, data); - goto out; + default: + return -EIO; + } + return put_user(tmp, ret); +} - case PTRACE_POKEUSR: - { - struct pt_regs *regs; - regs = task_pt_regs(child); +int ptrace_pokeusr(struct task_struct *child, long regno, long val) +{ + struct pt_regs *regs; + regs = task_pt_regs(child); - switch (addr) { + switch (regno) { case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1: - { - int ar = addr - REG_AR_BASE - regs->windowbase * 4; - if (ar < 16 && ar + (regs->wmask >> 4) * 4 >= 0) - regs->areg[ar & (XCHAL_NUM_AREGS - 1)] = data; - else - ret = -EIO; + regs->areg[regno - REG_AR_BASE] = val; break; - } + case REG_A_BASE ... REG_A_BASE + 15: - regs->areg[addr - REG_A_BASE] = data; + regs->areg[regno - REG_A_BASE] = val; break; + case REG_PC: - regs->pc = data; + regs->pc = val; break; + case SYSCALL_NR: - regs->syscall = data; - break; -#ifdef TEST_KERNEL - case REG_WB: - regs->windowbase = data; + regs->syscall = val; break; - case REG_WS: - regs->windowstart = data; - break; -#endif default: - /* The rest are not allowed. */ - ret = -EIO; - break; - } + return -EIO; + } + return 0; +} + +long arch_ptrace(struct task_struct *child, long request, long addr, long data) +{ + int ret = -EPERM; + + switch (request) { + case PTRACE_PEEKTEXT: /* read word at location addr. */ + case PTRACE_PEEKDATA: + ret = generic_ptrace_peekdata(child, addr, data); + break; + + case PTRACE_PEEKUSR: /* read register specified by addr. */ + ret = ptrace_peekusr(child, addr, (void __user *) data); + break; + + case PTRACE_POKETEXT: /* write the word at location addr. */ + case PTRACE_POKEDATA: + ret = generic_ptrace_pokedata(child, addr, data); + break; + + case PTRACE_POKEUSR: /* write register specified by addr. */ + ret = ptrace_pokeusr(child, addr, data); break; - } /* continue and stop at next (return from) syscall */ + case PTRACE_SYSCALL: case PTRACE_CONT: /* restart after signal. */ { @@ -217,98 +310,26 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data) break; case PTRACE_GETREGS: - { - /* 'data' points to user memory in which to write. - * Mainly due to the non-live register values, we - * reformat the register values into something more - * standard. For convenience, we use the handy - * elf_gregset_t format. */ - - xtensa_gregset_t format; - struct pt_regs *regs = task_pt_regs(child); - - do_copy_regs (&format, regs, child); - - /* Now, copy to user space nice and easy... */ - ret = 0; - if (copy_to_user((void *)data, &format, sizeof(elf_gregset_t))) - ret = -EFAULT; + ret = ptrace_getregs(child, (void __user *) data); break; - } case PTRACE_SETREGS: - { - /* 'data' points to user memory that contains the new - * values in the elf_gregset_t format. */ - - xtensa_gregset_t format; - struct pt_regs *regs = task_pt_regs(child); - - if (copy_from_user(&format,(void *)data,sizeof(elf_gregset_t))){ - ret = -EFAULT; - break; - } - - /* FIXME: Perhaps we want some sanity checks on - * these user-space values? See ARM version. Are - * debuggers a security concern? */ - - do_restore_regs (&format, regs, child); - - ret = 0; - break; - } - - case PTRACE_GETFPREGS: - { - /* 'data' points to user memory in which to write. - * For convenience, we use the handy - * elf_fpregset_t format. */ - - elf_fpregset_t fpregs; - struct pt_regs *regs = task_pt_regs(child); - - do_save_fpregs (&fpregs, regs, child); - - /* Now, copy to user space nice and easy... */ - ret = 0; - if (copy_to_user((void *)data, &fpregs, sizeof(elf_fpregset_t))) - ret = -EFAULT; - + ret = ptrace_setregs(child, (void __user *) data); break; - } - - case PTRACE_SETFPREGS: - { - /* 'data' points to user memory that contains the new - * values in the elf_fpregset_t format. - */ - elf_fpregset_t fpregs; - struct pt_regs *regs = task_pt_regs(child); - ret = 0; - if (copy_from_user(&fpregs, (void *)data, sizeof(elf_fpregset_t))) { - ret = -EFAULT; - break; - } - - if (do_restore_fpregs (&fpregs, regs, child)) - ret = -EIO; + case PTRACE_GETXTREGS: + ret = ptrace_getxregs(child, (void __user *) data); break; - } - case PTRACE_GETFPREGSIZE: - /* 'data' points to 'unsigned long' set to the size - * of elf_fpregset_t - */ - ret = put_user(sizeof(elf_fpregset_t), (unsigned long *) data); + case PTRACE_SETXTREGS: + ret = ptrace_setxregs(child, (void __user *) data); break; default: ret = ptrace_request(child, request, addr, data); - goto out; + break; } - out: + return ret; } -- cgit v1.2.2 From 42086cec3263b8c015ca3faa01e8190f0e3ff445 Mon Sep 17 00:00:00 2001 From: Chris Zankel Date: Mon, 28 Jan 2008 15:55:01 -0800 Subject: [XTENSA] Allow debugger to modify the WINDOWBASE register. For the 'return' command, GDB needs to adjust WINDOWBASE. In case WB is different from 0, we need to rotate the window register file and update WINDOWSTART and WMASK. This patch also removes some ret|= statements for __get_user/__put_user as the address range was alrady checked a couple of lines earlier. Signed-off-by: Chris Zankel --- arch/xtensa/kernel/ptrace.c | 66 ++++++++++++++++++++++++--------------------- 1 file changed, 35 insertions(+), 31 deletions(-) (limited to 'arch/xtensa/kernel/ptrace.c') diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c index f6669d605125..9486882ef0af 100644 --- a/arch/xtensa/kernel/ptrace.c +++ b/arch/xtensa/kernel/ptrace.c @@ -43,32 +43,29 @@ int ptrace_getregs(struct task_struct *child, void __user *uregs) { struct pt_regs *regs = task_pt_regs(child); xtensa_gregset_t __user *gregset = uregs; - unsigned long wb = regs->windowbase; - unsigned long ws = regs->windowstart; unsigned long wm = regs->wmask; - int ret = 0; - int live, last; + unsigned long wb = regs->windowbase; + int live, i; if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t))) return -EIO; - /* Norm windowstart to a windowbase of 0. */ - - ws = ((ws>>wb) | (ws<<(WSBITS-wb))) & ((1<pc, &gregset->pc); - ret |= __put_user(regs->ps & ~(1 << PS_EXCM_BIT), &gregset->ps); - ret |= __put_user(regs->lbeg, &gregset->lbeg); - ret |= __put_user(regs->lend, &gregset->lend); - ret |= __put_user(regs->lcount, &gregset->lcount); - ret |= __put_user(ws, &gregset->windowstart); + __put_user(regs->pc, &gregset->pc); + __put_user(regs->ps & ~(1 << PS_EXCM_BIT), &gregset->ps); + __put_user(regs->lbeg, &gregset->lbeg); + __put_user(regs->lend, &gregset->lend); + __put_user(regs->lcount, &gregset->lcount); + __put_user(regs->windowstart, &gregset->windowstart); + __put_user(regs->windowbase, &gregset->windowbase); live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16; - last = XCHAL_NUM_AREGS - (wm >> 4) * 4; - ret |= __copy_to_user(gregset->a, regs->areg, live * 4); - ret |= __copy_to_user(gregset->a + last, regs->areg + last, (wm>>4)*16); - return ret ? -EFAULT : 0; + for (i = 0; i < live; i++) + __put_user(regs->areg[i],gregset->a+((wb*4+i)%XCHAL_NUM_AREGS)); + for (i = XCHAL_NUM_AREGS - (wm >> 4) * 4; i < XCHAL_NUM_AREGS; i++) + __put_user(regs->areg[i],gregset->a+((wb*4+i)%XCHAL_NUM_AREGS)); + + return 0; } int ptrace_setregs(struct task_struct *child, void __user *uregs) @@ -76,28 +73,35 @@ int ptrace_setregs(struct task_struct *child, void __user *uregs) struct pt_regs *regs = task_pt_regs(child); xtensa_gregset_t *gregset = uregs; const unsigned long ps_mask = PS_CALLINC_MASK | PS_OWB_MASK; - unsigned long wm = regs->wmask; unsigned long ps; - int ret = 0; - int live, last; + unsigned long wb; if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t))) return -EIO; - ret |= __get_user(regs->pc, &gregset->pc); - ret |= __get_user(ps, &gregset->ps); - ret |= __get_user(regs->lbeg, &gregset->lbeg); - ret |= __get_user(regs->lend, &gregset->lend); - ret |= __get_user(regs->lcount, &gregset->lcount); + __get_user(regs->pc, &gregset->pc); + __get_user(ps, &gregset->ps); + __get_user(regs->lbeg, &gregset->lbeg); + __get_user(regs->lend, &gregset->lend); + __get_user(regs->lcount, &gregset->lcount); + __get_user(regs->windowstart, &gregset->windowstart); + __get_user(wb, &gregset->windowbase); regs->ps = (regs->ps & ~ps_mask) | (ps & ps_mask) | (1 << PS_EXCM_BIT); - live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16; - last = XCHAL_NUM_AREGS - (wm >> 4) * 4; - ret |= __copy_from_user(regs->areg, gregset->a, live * 4); - ret |= __copy_from_user(regs->areg+last, gregset->a+last, (wm>>4)*16); + if (wb >= XCHAL_NUM_AREGS / 4) + return -EFAULT; - return ret ? -EFAULT : 0; + regs->windowbase = wb; + + if (wb != 0 && __copy_from_user(regs->areg + XCHAL_NUM_AREGS - wb * 4, + gregset->a, wb * 16)) + return -EFAULT; + + if (__copy_from_user(regs->areg, gregset->a + wb*4, (WSBITS-wb) * 16)) + return -EFAULT; + + return 0; } -- cgit v1.2.2