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-rw-r--r--arch/xtensa/kernel/ptrace.c585
1 files changed, 585 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c
new file mode 100644
index 000000000..f29477162
--- /dev/null
+++ b/arch/xtensa/kernel/ptrace.c
@@ -0,0 +1,585 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2007 Tensilica Inc.
+ *
+ * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
+ * Chris Zankel <chris@zankel.net>
+ * Scott Foehner<sfoehner@yahoo.com>,
+ * Kevin Chea
+ * Marc Gauthier<marc@tensilica.com> <marc@alumni.uwaterloo.ca>
+ */
+
+#include <linux/audit.h>
+#include <linux/errno.h>
+#include <linux/hw_breakpoint.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/perf_event.h>
+#include <linux/ptrace.h>
+#include <linux/regset.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <linux/seccomp.h>
+#include <linux/security.h>
+#include <linux/signal.h>
+#include <linux/smp.h>
+#include <linux/uaccess.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/syscalls.h>
+
+#include <asm/coprocessor.h>
+#include <asm/elf.h>
+#include <asm/page.h>
+#include <asm/ptrace.h>
+
+static int gpr_get(struct task_struct *target,
+ const struct user_regset *regset,
+ struct membuf to)
+{
+ struct pt_regs *regs = task_pt_regs(target);
+ struct user_pt_regs newregs = {
+ .pc = regs->pc,
+ .ps = regs->ps & ~(1 << PS_EXCM_BIT),
+ .lbeg = regs->lbeg,
+ .lend = regs->lend,
+ .lcount = regs->lcount,
+ .sar = regs->sar,
+ .threadptr = regs->threadptr,
+ .windowbase = regs->windowbase,
+ .windowstart = regs->windowstart,
+ .syscall = regs->syscall,
+ };
+
+ memcpy(newregs.a,
+ regs->areg + XCHAL_NUM_AREGS - regs->windowbase * 4,
+ regs->windowbase * 16);
+ memcpy(newregs.a + regs->windowbase * 4,
+ regs->areg,
+ (WSBITS - regs->windowbase) * 16);
+
+ return membuf_write(&to, &newregs, sizeof(newregs));
+}
+
+static int gpr_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ int ret;
+ struct user_pt_regs newregs = {0};
+ struct pt_regs *regs;
+ const u32 ps_mask = PS_CALLINC_MASK | PS_OWB_MASK;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
+ if (ret)
+ return ret;
+
+ if (newregs.windowbase >= XCHAL_NUM_AREGS / 4)
+ return -EINVAL;
+
+ regs = task_pt_regs(target);
+ regs->pc = newregs.pc;
+ regs->ps = (regs->ps & ~ps_mask) | (newregs.ps & ps_mask);
+ regs->lbeg = newregs.lbeg;
+ regs->lend = newregs.lend;
+ regs->lcount = newregs.lcount;
+ regs->sar = newregs.sar;
+ regs->threadptr = newregs.threadptr;
+
+ if (newregs.syscall)
+ regs->syscall = newregs.syscall;
+
+ if (newregs.windowbase != regs->windowbase ||
+ newregs.windowstart != regs->windowstart) {
+ u32 rotws, wmask;
+
+ rotws = (((newregs.windowstart |
+ (newregs.windowstart << WSBITS)) >>
+ newregs.windowbase) &
+ ((1 << WSBITS) - 1)) & ~1;
+ wmask = ((rotws ? WSBITS + 1 - ffs(rotws) : 0) << 4) |
+ (rotws & 0xF) | 1;
+ regs->windowbase = newregs.windowbase;
+ regs->windowstart = newregs.windowstart;
+ regs->wmask = wmask;
+ }
+
+ memcpy(regs->areg + XCHAL_NUM_AREGS - newregs.windowbase * 4,
+ newregs.a, newregs.windowbase * 16);
+ memcpy(regs->areg, newregs.a + newregs.windowbase * 4,
+ (WSBITS - newregs.windowbase) * 16);
+
+ return 0;
+}
+
+static int tie_get(struct task_struct *target,
+ const struct user_regset *regset,
+ struct membuf to)
+{
+ int ret;
+ struct pt_regs *regs = task_pt_regs(target);
+ struct thread_info *ti = task_thread_info(target);
+ elf_xtregs_t *newregs = kzalloc(sizeof(elf_xtregs_t), GFP_KERNEL);
+
+ if (!newregs)
+ return -ENOMEM;
+
+ newregs->opt = regs->xtregs_opt;
+ newregs->user = ti->xtregs_user;
+
+#if XTENSA_HAVE_COPROCESSORS
+ /* Flush all coprocessor registers to memory. */
+ coprocessor_flush_all(ti);
+ newregs->cp0 = ti->xtregs_cp.cp0;
+ newregs->cp1 = ti->xtregs_cp.cp1;
+ newregs->cp2 = ti->xtregs_cp.cp2;
+ newregs->cp3 = ti->xtregs_cp.cp3;
+ newregs->cp4 = ti->xtregs_cp.cp4;
+ newregs->cp5 = ti->xtregs_cp.cp5;
+ newregs->cp6 = ti->xtregs_cp.cp6;
+ newregs->cp7 = ti->xtregs_cp.cp7;
+#endif
+ ret = membuf_write(&to, newregs, sizeof(*newregs));
+ kfree(newregs);
+ return ret;
+}
+
+static int tie_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ int ret;
+ struct pt_regs *regs = task_pt_regs(target);
+ struct thread_info *ti = task_thread_info(target);
+ elf_xtregs_t *newregs = kzalloc(sizeof(elf_xtregs_t), GFP_KERNEL);
+
+ if (!newregs)
+ return -ENOMEM;
+
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ newregs, 0, -1);
+
+ if (ret)
+ goto exit;
+ regs->xtregs_opt = newregs->opt;
+ ti->xtregs_user = newregs->user;
+
+#if XTENSA_HAVE_COPROCESSORS
+ /* Flush all coprocessors before we overwrite them. */
+ coprocessor_flush_release_all(ti);
+ ti->xtregs_cp.cp0 = newregs->cp0;
+ ti->xtregs_cp.cp1 = newregs->cp1;
+ ti->xtregs_cp.cp2 = newregs->cp2;
+ ti->xtregs_cp.cp3 = newregs->cp3;
+ ti->xtregs_cp.cp4 = newregs->cp4;
+ ti->xtregs_cp.cp5 = newregs->cp5;
+ ti->xtregs_cp.cp6 = newregs->cp6;
+ ti->xtregs_cp.cp7 = newregs->cp7;
+#endif
+exit:
+ kfree(newregs);
+ return ret;
+}
+
+enum xtensa_regset {
+ REGSET_GPR,
+ REGSET_TIE,
+};
+
+static const struct user_regset xtensa_regsets[] = {
+ [REGSET_GPR] = {
+ .core_note_type = NT_PRSTATUS,
+ .n = sizeof(struct user_pt_regs) / sizeof(u32),
+ .size = sizeof(u32),
+ .align = sizeof(u32),
+ .regset_get = gpr_get,
+ .set = gpr_set,
+ },
+ [REGSET_TIE] = {
+ .core_note_type = NT_PRFPREG,
+ .n = sizeof(elf_xtregs_t) / sizeof(u32),
+ .size = sizeof(u32),
+ .align = sizeof(u32),
+ .regset_get = tie_get,
+ .set = tie_set,
+ },
+};
+
+static const struct user_regset_view user_xtensa_view = {
+ .name = "xtensa",
+ .e_machine = EM_XTENSA,
+ .regsets = xtensa_regsets,
+ .n = ARRAY_SIZE(xtensa_regsets)
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+ return &user_xtensa_view;
+}
+
+void user_enable_single_step(struct task_struct *child)
+{
+ set_tsk_thread_flag(child, TIF_SINGLESTEP);
+}
+
+void user_disable_single_step(struct task_struct *child)
+{
+ clear_tsk_thread_flag(child, TIF_SINGLESTEP);
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching to disable single stepping.
+ */
+
+void ptrace_disable(struct task_struct *child)
+{
+ /* Nothing to do.. */
+}
+
+static int ptrace_getregs(struct task_struct *child, void __user *uregs)
+{
+ return copy_regset_to_user(child, &user_xtensa_view, REGSET_GPR,
+ 0, sizeof(xtensa_gregset_t), uregs);
+}
+
+static int ptrace_setregs(struct task_struct *child, void __user *uregs)
+{
+ return copy_regset_from_user(child, &user_xtensa_view, REGSET_GPR,
+ 0, sizeof(xtensa_gregset_t), uregs);
+}
+
+static int ptrace_getxregs(struct task_struct *child, void __user *uregs)
+{
+ return copy_regset_to_user(child, &user_xtensa_view, REGSET_TIE,
+ 0, sizeof(elf_xtregs_t), uregs);
+}
+
+static int ptrace_setxregs(struct task_struct *child, void __user *uregs)
+{
+ return copy_regset_from_user(child, &user_xtensa_view, REGSET_TIE,
+ 0, sizeof(elf_xtregs_t), uregs);
+}
+
+static 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(regno) {
+ case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
+ tmp = regs->areg[regno - REG_AR_BASE];
+ break;
+
+ case REG_A_BASE ... REG_A_BASE + 15:
+ 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:
+ break; /* tmp = 0 */
+
+ case REG_WS:
+ {
+ unsigned long wb = regs->windowbase;
+ unsigned long ws = regs->windowstart;
+ tmp = ((ws >> wb) | (ws << (WSBITS - wb))) &
+ ((1 << WSBITS) - 1);
+ break;
+ }
+ case REG_LBEG:
+ tmp = regs->lbeg;
+ break;
+
+ case REG_LEND:
+ tmp = regs->lend;
+ break;
+
+ case REG_LCOUNT:
+ tmp = regs->lcount;
+ break;
+
+ case REG_SAR:
+ tmp = regs->sar;
+ break;
+
+ case SYSCALL_NR:
+ tmp = regs->syscall;
+ break;
+
+ default:
+ return -EIO;
+ }
+ return put_user(tmp, ret);
+}
+
+static int ptrace_pokeusr(struct task_struct *child, long regno, long val)
+{
+ struct pt_regs *regs;
+ regs = task_pt_regs(child);
+
+ switch (regno) {
+ case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
+ regs->areg[regno - REG_AR_BASE] = val;
+ break;
+
+ case REG_A_BASE ... REG_A_BASE + 15:
+ regs->areg[regno - REG_A_BASE] = val;
+ break;
+
+ case REG_PC:
+ regs->pc = val;
+ break;
+
+ case SYSCALL_NR:
+ regs->syscall = val;
+ break;
+
+ default:
+ return -EIO;
+ }
+ return 0;
+}
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+static void ptrace_hbptriggered(struct perf_event *bp,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ int i;
+ struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
+
+ if (bp->attr.bp_type & HW_BREAKPOINT_X) {
+ for (i = 0; i < XCHAL_NUM_IBREAK; ++i)
+ if (current->thread.ptrace_bp[i] == bp)
+ break;
+ i <<= 1;
+ } else {
+ for (i = 0; i < XCHAL_NUM_DBREAK; ++i)
+ if (current->thread.ptrace_wp[i] == bp)
+ break;
+ i = (i << 1) | 1;
+ }
+
+ force_sig_ptrace_errno_trap(i, (void __user *)bkpt->address);
+}
+
+static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
+{
+ struct perf_event_attr attr;
+
+ ptrace_breakpoint_init(&attr);
+
+ /* Initialise fields to sane defaults. */
+ attr.bp_addr = 0;
+ attr.bp_len = 1;
+ attr.bp_type = type;
+ attr.disabled = 1;
+
+ return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL,
+ tsk);
+}
+
+/*
+ * Address bit 0 choose instruction (0) or data (1) break register, bits
+ * 31..1 are the register number.
+ * Both PTRACE_GETHBPREGS and PTRACE_SETHBPREGS transfer two 32-bit words:
+ * address (0) and control (1).
+ * Instruction breakpoint contorl word is 0 to clear breakpoint, 1 to set.
+ * Data breakpoint control word bit 31 is 'trigger on store', bit 30 is
+ * 'trigger on load, bits 29..0 are length. Length 0 is used to clear a
+ * breakpoint. To set a breakpoint length must be a power of 2 in the range
+ * 1..64 and the address must be length-aligned.
+ */
+
+static long ptrace_gethbpregs(struct task_struct *child, long addr,
+ long __user *datap)
+{
+ struct perf_event *bp;
+ u32 user_data[2] = {0};
+ bool dbreak = addr & 1;
+ unsigned idx = addr >> 1;
+
+ if ((!dbreak && idx >= XCHAL_NUM_IBREAK) ||
+ (dbreak && idx >= XCHAL_NUM_DBREAK))
+ return -EINVAL;
+
+ if (dbreak)
+ bp = child->thread.ptrace_wp[idx];
+ else
+ bp = child->thread.ptrace_bp[idx];
+
+ if (bp) {
+ user_data[0] = bp->attr.bp_addr;
+ user_data[1] = bp->attr.disabled ? 0 : bp->attr.bp_len;
+ if (dbreak) {
+ if (bp->attr.bp_type & HW_BREAKPOINT_R)
+ user_data[1] |= DBREAKC_LOAD_MASK;
+ if (bp->attr.bp_type & HW_BREAKPOINT_W)
+ user_data[1] |= DBREAKC_STOR_MASK;
+ }
+ }
+
+ if (copy_to_user(datap, user_data, sizeof(user_data)))
+ return -EFAULT;
+
+ return 0;
+}
+
+static long ptrace_sethbpregs(struct task_struct *child, long addr,
+ long __user *datap)
+{
+ struct perf_event *bp;
+ struct perf_event_attr attr;
+ u32 user_data[2];
+ bool dbreak = addr & 1;
+ unsigned idx = addr >> 1;
+ int bp_type = 0;
+
+ if ((!dbreak && idx >= XCHAL_NUM_IBREAK) ||
+ (dbreak && idx >= XCHAL_NUM_DBREAK))
+ return -EINVAL;
+
+ if (copy_from_user(user_data, datap, sizeof(user_data)))
+ return -EFAULT;
+
+ if (dbreak) {
+ bp = child->thread.ptrace_wp[idx];
+ if (user_data[1] & DBREAKC_LOAD_MASK)
+ bp_type |= HW_BREAKPOINT_R;
+ if (user_data[1] & DBREAKC_STOR_MASK)
+ bp_type |= HW_BREAKPOINT_W;
+ } else {
+ bp = child->thread.ptrace_bp[idx];
+ bp_type = HW_BREAKPOINT_X;
+ }
+
+ if (!bp) {
+ bp = ptrace_hbp_create(child,
+ bp_type ? bp_type : HW_BREAKPOINT_RW);
+ if (IS_ERR(bp))
+ return PTR_ERR(bp);
+ if (dbreak)
+ child->thread.ptrace_wp[idx] = bp;
+ else
+ child->thread.ptrace_bp[idx] = bp;
+ }
+
+ attr = bp->attr;
+ attr.bp_addr = user_data[0];
+ attr.bp_len = user_data[1] & ~(DBREAKC_LOAD_MASK | DBREAKC_STOR_MASK);
+ attr.bp_type = bp_type;
+ attr.disabled = !attr.bp_len;
+
+ return modify_user_hw_breakpoint(bp, &attr);
+}
+#endif
+
+long arch_ptrace(struct task_struct *child, long request,
+ unsigned long addr, unsigned long data)
+{
+ int ret = -EPERM;
+ void __user *datap = (void __user *) data;
+
+ switch (request) {
+ case PTRACE_PEEKUSR: /* read register specified by addr. */
+ ret = ptrace_peekusr(child, addr, datap);
+ break;
+
+ case PTRACE_POKEUSR: /* write register specified by addr. */
+ ret = ptrace_pokeusr(child, addr, data);
+ break;
+
+ case PTRACE_GETREGS:
+ ret = ptrace_getregs(child, datap);
+ break;
+
+ case PTRACE_SETREGS:
+ ret = ptrace_setregs(child, datap);
+ break;
+
+ case PTRACE_GETXTREGS:
+ ret = ptrace_getxregs(child, datap);
+ break;
+
+ case PTRACE_SETXTREGS:
+ ret = ptrace_setxregs(child, datap);
+ break;
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ case PTRACE_GETHBPREGS:
+ ret = ptrace_gethbpregs(child, addr, datap);
+ break;
+
+ case PTRACE_SETHBPREGS:
+ ret = ptrace_sethbpregs(child, addr, datap);
+ break;
+#endif
+ default:
+ ret = ptrace_request(child, request, addr, data);
+ break;
+ }
+
+ return ret;
+}
+
+void do_syscall_trace_leave(struct pt_regs *regs);
+int do_syscall_trace_enter(struct pt_regs *regs)
+{
+ if (regs->syscall == NO_SYSCALL)
+ regs->areg[2] = -ENOSYS;
+
+ if (test_thread_flag(TIF_SYSCALL_TRACE) &&
+ ptrace_report_syscall_entry(regs)) {
+ regs->areg[2] = -ENOSYS;
+ regs->syscall = NO_SYSCALL;
+ return 0;
+ }
+
+ if (regs->syscall == NO_SYSCALL ||
+ secure_computing() == -1) {
+ do_syscall_trace_leave(regs);
+ return 0;
+ }
+
+ if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+ trace_sys_enter(regs, syscall_get_nr(current, regs));
+
+ audit_syscall_entry(regs->syscall, regs->areg[6],
+ regs->areg[3], regs->areg[4],
+ regs->areg[5]);
+ return 1;
+}
+
+void do_syscall_trace_leave(struct pt_regs *regs)
+{
+ int step;
+
+ audit_syscall_exit(regs);
+
+ if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+ trace_sys_exit(regs, regs_return_value(regs));
+
+ step = test_thread_flag(TIF_SINGLESTEP);
+
+ if (step || test_thread_flag(TIF_SYSCALL_TRACE))
+ ptrace_report_syscall_exit(regs, step);
+}