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-rw-r--r--arch/x86/kernel/ptrace.c1423
1 files changed, 1423 insertions, 0 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
new file mode 100644
index 0000000000..095f04bdab
--- /dev/null
+++ b/arch/x86/kernel/ptrace.c
@@ -0,0 +1,1423 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* By Ross Biro 1/23/92 */
+/*
+ * Pentium III FXSR, SSE support
+ * Gareth Hughes <gareth@valinux.com>, May 2000
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/elf.h>
+#include <linux/security.h>
+#include <linux/audit.h>
+#include <linux/seccomp.h>
+#include <linux/signal.h>
+#include <linux/perf_event.h>
+#include <linux/hw_breakpoint.h>
+#include <linux/rcupdate.h>
+#include <linux/export.h>
+#include <linux/context_tracking.h>
+#include <linux/nospec.h>
+
+#include <linux/uaccess.h>
+#include <asm/processor.h>
+#include <asm/fpu/signal.h>
+#include <asm/fpu/regset.h>
+#include <asm/fpu/xstate.h>
+#include <asm/debugreg.h>
+#include <asm/ldt.h>
+#include <asm/desc.h>
+#include <asm/prctl.h>
+#include <asm/proto.h>
+#include <asm/hw_breakpoint.h>
+#include <asm/traps.h>
+#include <asm/syscall.h>
+#include <asm/fsgsbase.h>
+#include <asm/io_bitmap.h>
+
+#include "tls.h"
+
+enum x86_regset_32 {
+ REGSET32_GENERAL,
+ REGSET32_FP,
+ REGSET32_XFP,
+ REGSET32_XSTATE,
+ REGSET32_TLS,
+ REGSET32_IOPERM,
+};
+
+enum x86_regset_64 {
+ REGSET64_GENERAL,
+ REGSET64_FP,
+ REGSET64_IOPERM,
+ REGSET64_XSTATE,
+ REGSET64_SSP,
+};
+
+#define REGSET_GENERAL \
+({ \
+ BUILD_BUG_ON((int)REGSET32_GENERAL != (int)REGSET64_GENERAL); \
+ REGSET32_GENERAL; \
+})
+
+#define REGSET_FP \
+({ \
+ BUILD_BUG_ON((int)REGSET32_FP != (int)REGSET64_FP); \
+ REGSET32_FP; \
+})
+
+
+struct pt_regs_offset {
+ const char *name;
+ int offset;
+};
+
+#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
+#define REG_OFFSET_END {.name = NULL, .offset = 0}
+
+static const struct pt_regs_offset regoffset_table[] = {
+#ifdef CONFIG_X86_64
+ REG_OFFSET_NAME(r15),
+ REG_OFFSET_NAME(r14),
+ REG_OFFSET_NAME(r13),
+ REG_OFFSET_NAME(r12),
+ REG_OFFSET_NAME(r11),
+ REG_OFFSET_NAME(r10),
+ REG_OFFSET_NAME(r9),
+ REG_OFFSET_NAME(r8),
+#endif
+ REG_OFFSET_NAME(bx),
+ REG_OFFSET_NAME(cx),
+ REG_OFFSET_NAME(dx),
+ REG_OFFSET_NAME(si),
+ REG_OFFSET_NAME(di),
+ REG_OFFSET_NAME(bp),
+ REG_OFFSET_NAME(ax),
+#ifdef CONFIG_X86_32
+ REG_OFFSET_NAME(ds),
+ REG_OFFSET_NAME(es),
+ REG_OFFSET_NAME(fs),
+ REG_OFFSET_NAME(gs),
+#endif
+ REG_OFFSET_NAME(orig_ax),
+ REG_OFFSET_NAME(ip),
+ REG_OFFSET_NAME(cs),
+ REG_OFFSET_NAME(flags),
+ REG_OFFSET_NAME(sp),
+ REG_OFFSET_NAME(ss),
+ REG_OFFSET_END,
+};
+
+/**
+ * regs_query_register_offset() - query register offset from its name
+ * @name: the name of a register
+ *
+ * regs_query_register_offset() returns the offset of a register in struct
+ * pt_regs from its name. If the name is invalid, this returns -EINVAL;
+ */
+int regs_query_register_offset(const char *name)
+{
+ const struct pt_regs_offset *roff;
+ for (roff = regoffset_table; roff->name != NULL; roff++)
+ if (!strcmp(roff->name, name))
+ return roff->offset;
+ return -EINVAL;
+}
+
+/**
+ * regs_query_register_name() - query register name from its offset
+ * @offset: the offset of a register in struct pt_regs.
+ *
+ * regs_query_register_name() returns the name of a register from its
+ * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
+ */
+const char *regs_query_register_name(unsigned int offset)
+{
+ const struct pt_regs_offset *roff;
+ for (roff = regoffset_table; roff->name != NULL; roff++)
+ if (roff->offset == offset)
+ return roff->name;
+ return NULL;
+}
+
+/*
+ * does not yet catch signals sent when the child dies.
+ * in exit.c or in signal.c.
+ */
+
+/*
+ * Determines which flags the user has access to [1 = access, 0 = no access].
+ */
+#define FLAG_MASK_32 ((unsigned long) \
+ (X86_EFLAGS_CF | X86_EFLAGS_PF | \
+ X86_EFLAGS_AF | X86_EFLAGS_ZF | \
+ X86_EFLAGS_SF | X86_EFLAGS_TF | \
+ X86_EFLAGS_DF | X86_EFLAGS_OF | \
+ X86_EFLAGS_RF | X86_EFLAGS_AC))
+
+/*
+ * Determines whether a value may be installed in a segment register.
+ */
+static inline bool invalid_selector(u16 value)
+{
+ return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
+}
+
+#ifdef CONFIG_X86_32
+
+#define FLAG_MASK FLAG_MASK_32
+
+static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
+{
+ BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
+ return &regs->bx + (regno >> 2);
+}
+
+static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
+{
+ /*
+ * Returning the value truncates it to 16 bits.
+ */
+ unsigned int retval;
+ if (offset != offsetof(struct user_regs_struct, gs))
+ retval = *pt_regs_access(task_pt_regs(task), offset);
+ else {
+ if (task == current)
+ savesegment(gs, retval);
+ else
+ retval = task->thread.gs;
+ }
+ return retval;
+}
+
+static int set_segment_reg(struct task_struct *task,
+ unsigned long offset, u16 value)
+{
+ if (WARN_ON_ONCE(task == current))
+ return -EIO;
+
+ /*
+ * The value argument was already truncated to 16 bits.
+ */
+ if (invalid_selector(value))
+ return -EIO;
+
+ /*
+ * For %cs and %ss we cannot permit a null selector.
+ * We can permit a bogus selector as long as it has USER_RPL.
+ * Null selectors are fine for other segment registers, but
+ * we will never get back to user mode with invalid %cs or %ss
+ * and will take the trap in iret instead. Much code relies
+ * on user_mode() to distinguish a user trap frame (which can
+ * safely use invalid selectors) from a kernel trap frame.
+ */
+ switch (offset) {
+ case offsetof(struct user_regs_struct, cs):
+ case offsetof(struct user_regs_struct, ss):
+ if (unlikely(value == 0))
+ return -EIO;
+ fallthrough;
+
+ default:
+ *pt_regs_access(task_pt_regs(task), offset) = value;
+ break;
+
+ case offsetof(struct user_regs_struct, gs):
+ task->thread.gs = value;
+ }
+
+ return 0;
+}
+
+#else /* CONFIG_X86_64 */
+
+#define FLAG_MASK (FLAG_MASK_32 | X86_EFLAGS_NT)
+
+static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
+{
+ BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
+ return &regs->r15 + (offset / sizeof(regs->r15));
+}
+
+static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
+{
+ /*
+ * Returning the value truncates it to 16 bits.
+ */
+ unsigned int seg;
+
+ switch (offset) {
+ case offsetof(struct user_regs_struct, fs):
+ if (task == current) {
+ /* Older gas can't assemble movq %?s,%r?? */
+ asm("movl %%fs,%0" : "=r" (seg));
+ return seg;
+ }
+ return task->thread.fsindex;
+ case offsetof(struct user_regs_struct, gs):
+ if (task == current) {
+ asm("movl %%gs,%0" : "=r" (seg));
+ return seg;
+ }
+ return task->thread.gsindex;
+ case offsetof(struct user_regs_struct, ds):
+ if (task == current) {
+ asm("movl %%ds,%0" : "=r" (seg));
+ return seg;
+ }
+ return task->thread.ds;
+ case offsetof(struct user_regs_struct, es):
+ if (task == current) {
+ asm("movl %%es,%0" : "=r" (seg));
+ return seg;
+ }
+ return task->thread.es;
+
+ case offsetof(struct user_regs_struct, cs):
+ case offsetof(struct user_regs_struct, ss):
+ break;
+ }
+ return *pt_regs_access(task_pt_regs(task), offset);
+}
+
+static int set_segment_reg(struct task_struct *task,
+ unsigned long offset, u16 value)
+{
+ if (WARN_ON_ONCE(task == current))
+ return -EIO;
+
+ /*
+ * The value argument was already truncated to 16 bits.
+ */
+ if (invalid_selector(value))
+ return -EIO;
+
+ /*
+ * Writes to FS and GS will change the stored selector. Whether
+ * this changes the segment base as well depends on whether
+ * FSGSBASE is enabled.
+ */
+
+ switch (offset) {
+ case offsetof(struct user_regs_struct,fs):
+ task->thread.fsindex = value;
+ break;
+ case offsetof(struct user_regs_struct,gs):
+ task->thread.gsindex = value;
+ break;
+ case offsetof(struct user_regs_struct,ds):
+ task->thread.ds = value;
+ break;
+ case offsetof(struct user_regs_struct,es):
+ task->thread.es = value;
+ break;
+
+ /*
+ * Can't actually change these in 64-bit mode.
+ */
+ case offsetof(struct user_regs_struct,cs):
+ if (unlikely(value == 0))
+ return -EIO;
+ task_pt_regs(task)->cs = value;
+ break;
+ case offsetof(struct user_regs_struct,ss):
+ if (unlikely(value == 0))
+ return -EIO;
+ task_pt_regs(task)->ss = value;
+ break;
+ }
+
+ return 0;
+}
+
+#endif /* CONFIG_X86_32 */
+
+static unsigned long get_flags(struct task_struct *task)
+{
+ unsigned long retval = task_pt_regs(task)->flags;
+
+ /*
+ * If the debugger set TF, hide it from the readout.
+ */
+ if (test_tsk_thread_flag(task, TIF_FORCED_TF))
+ retval &= ~X86_EFLAGS_TF;
+
+ return retval;
+}
+
+static int set_flags(struct task_struct *task, unsigned long value)
+{
+ struct pt_regs *regs = task_pt_regs(task);
+
+ /*
+ * If the user value contains TF, mark that
+ * it was not "us" (the debugger) that set it.
+ * If not, make sure it stays set if we had.
+ */
+ if (value & X86_EFLAGS_TF)
+ clear_tsk_thread_flag(task, TIF_FORCED_TF);
+ else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
+ value |= X86_EFLAGS_TF;
+
+ regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
+
+ return 0;
+}
+
+static int putreg(struct task_struct *child,
+ unsigned long offset, unsigned long value)
+{
+ switch (offset) {
+ case offsetof(struct user_regs_struct, cs):
+ case offsetof(struct user_regs_struct, ds):
+ case offsetof(struct user_regs_struct, es):
+ case offsetof(struct user_regs_struct, fs):
+ case offsetof(struct user_regs_struct, gs):
+ case offsetof(struct user_regs_struct, ss):
+ return set_segment_reg(child, offset, value);
+
+ case offsetof(struct user_regs_struct, flags):
+ return set_flags(child, value);
+
+#ifdef CONFIG_X86_64
+ case offsetof(struct user_regs_struct,fs_base):
+ if (value >= TASK_SIZE_MAX)
+ return -EIO;
+ x86_fsbase_write_task(child, value);
+ return 0;
+ case offsetof(struct user_regs_struct,gs_base):
+ if (value >= TASK_SIZE_MAX)
+ return -EIO;
+ x86_gsbase_write_task(child, value);
+ return 0;
+#endif
+ }
+
+ *pt_regs_access(task_pt_regs(child), offset) = value;
+ return 0;
+}
+
+static unsigned long getreg(struct task_struct *task, unsigned long offset)
+{
+ switch (offset) {
+ case offsetof(struct user_regs_struct, cs):
+ case offsetof(struct user_regs_struct, ds):
+ case offsetof(struct user_regs_struct, es):
+ case offsetof(struct user_regs_struct, fs):
+ case offsetof(struct user_regs_struct, gs):
+ case offsetof(struct user_regs_struct, ss):
+ return get_segment_reg(task, offset);
+
+ case offsetof(struct user_regs_struct, flags):
+ return get_flags(task);
+
+#ifdef CONFIG_X86_64
+ case offsetof(struct user_regs_struct, fs_base):
+ return x86_fsbase_read_task(task);
+ case offsetof(struct user_regs_struct, gs_base):
+ return x86_gsbase_read_task(task);
+#endif
+ }
+
+ return *pt_regs_access(task_pt_regs(task), offset);
+}
+
+static int genregs_get(struct task_struct *target,
+ const struct user_regset *regset,
+ struct membuf to)
+{
+ int reg;
+
+ for (reg = 0; to.left; reg++)
+ membuf_store(&to, getreg(target, reg * sizeof(unsigned long)));
+ return 0;
+}
+
+static int genregs_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 = 0;
+ if (kbuf) {
+ const unsigned long *k = kbuf;
+ while (count >= sizeof(*k) && !ret) {
+ ret = putreg(target, pos, *k++);
+ count -= sizeof(*k);
+ pos += sizeof(*k);
+ }
+ } else {
+ const unsigned long __user *u = ubuf;
+ while (count >= sizeof(*u) && !ret) {
+ unsigned long word;
+ ret = __get_user(word, u++);
+ if (ret)
+ break;
+ ret = putreg(target, pos, word);
+ count -= sizeof(*u);
+ pos += sizeof(*u);
+ }
+ }
+ return ret;
+}
+
+static void ptrace_triggered(struct perf_event *bp,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ int i;
+ struct thread_struct *thread = &(current->thread);
+
+ /*
+ * Store in the virtual DR6 register the fact that the breakpoint
+ * was hit so the thread's debugger will see it.
+ */
+ for (i = 0; i < HBP_NUM; i++) {
+ if (thread->ptrace_bps[i] == bp)
+ break;
+ }
+
+ thread->virtual_dr6 |= (DR_TRAP0 << i);
+}
+
+/*
+ * Walk through every ptrace breakpoints for this thread and
+ * build the dr7 value on top of their attributes.
+ *
+ */
+static unsigned long ptrace_get_dr7(struct perf_event *bp[])
+{
+ int i;
+ int dr7 = 0;
+ struct arch_hw_breakpoint *info;
+
+ for (i = 0; i < HBP_NUM; i++) {
+ if (bp[i] && !bp[i]->attr.disabled) {
+ info = counter_arch_bp(bp[i]);
+ dr7 |= encode_dr7(i, info->len, info->type);
+ }
+ }
+
+ return dr7;
+}
+
+static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
+ int len, int type, bool disabled)
+{
+ int err, bp_len, bp_type;
+
+ err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
+ if (!err) {
+ attr->bp_len = bp_len;
+ attr->bp_type = bp_type;
+ attr->disabled = disabled;
+ }
+
+ return err;
+}
+
+static struct perf_event *
+ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
+ unsigned long addr, bool disabled)
+{
+ struct perf_event_attr attr;
+ int err;
+
+ ptrace_breakpoint_init(&attr);
+ attr.bp_addr = addr;
+
+ err = ptrace_fill_bp_fields(&attr, len, type, disabled);
+ if (err)
+ return ERR_PTR(err);
+
+ return register_user_hw_breakpoint(&attr, ptrace_triggered,
+ NULL, tsk);
+}
+
+static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
+ int disabled)
+{
+ struct perf_event_attr attr = bp->attr;
+ int err;
+
+ err = ptrace_fill_bp_fields(&attr, len, type, disabled);
+ if (err)
+ return err;
+
+ return modify_user_hw_breakpoint(bp, &attr);
+}
+
+/*
+ * Handle ptrace writes to debug register 7.
+ */
+static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
+{
+ struct thread_struct *thread = &tsk->thread;
+ unsigned long old_dr7;
+ bool second_pass = false;
+ int i, rc, ret = 0;
+
+ data &= ~DR_CONTROL_RESERVED;
+ old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
+
+restore:
+ rc = 0;
+ for (i = 0; i < HBP_NUM; i++) {
+ unsigned len, type;
+ bool disabled = !decode_dr7(data, i, &len, &type);
+ struct perf_event *bp = thread->ptrace_bps[i];
+
+ if (!bp) {
+ if (disabled)
+ continue;
+
+ bp = ptrace_register_breakpoint(tsk,
+ len, type, 0, disabled);
+ if (IS_ERR(bp)) {
+ rc = PTR_ERR(bp);
+ break;
+ }
+
+ thread->ptrace_bps[i] = bp;
+ continue;
+ }
+
+ rc = ptrace_modify_breakpoint(bp, len, type, disabled);
+ if (rc)
+ break;
+ }
+
+ /* Restore if the first pass failed, second_pass shouldn't fail. */
+ if (rc && !WARN_ON(second_pass)) {
+ ret = rc;
+ data = old_dr7;
+ second_pass = true;
+ goto restore;
+ }
+
+ return ret;
+}
+
+/*
+ * Handle PTRACE_PEEKUSR calls for the debug register area.
+ */
+static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
+{
+ struct thread_struct *thread = &tsk->thread;
+ unsigned long val = 0;
+
+ if (n < HBP_NUM) {
+ int index = array_index_nospec(n, HBP_NUM);
+ struct perf_event *bp = thread->ptrace_bps[index];
+
+ if (bp)
+ val = bp->hw.info.address;
+ } else if (n == 6) {
+ val = thread->virtual_dr6 ^ DR6_RESERVED; /* Flip back to arch polarity */
+ } else if (n == 7) {
+ val = thread->ptrace_dr7;
+ }
+ return val;
+}
+
+static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
+ unsigned long addr)
+{
+ struct thread_struct *t = &tsk->thread;
+ struct perf_event *bp = t->ptrace_bps[nr];
+ int err = 0;
+
+ if (!bp) {
+ /*
+ * Put stub len and type to create an inactive but correct bp.
+ *
+ * CHECKME: the previous code returned -EIO if the addr wasn't
+ * a valid task virtual addr. The new one will return -EINVAL in
+ * this case.
+ * -EINVAL may be what we want for in-kernel breakpoints users,
+ * but -EIO looks better for ptrace, since we refuse a register
+ * writing for the user. And anyway this is the previous
+ * behaviour.
+ */
+ bp = ptrace_register_breakpoint(tsk,
+ X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
+ addr, true);
+ if (IS_ERR(bp))
+ err = PTR_ERR(bp);
+ else
+ t->ptrace_bps[nr] = bp;
+ } else {
+ struct perf_event_attr attr = bp->attr;
+
+ attr.bp_addr = addr;
+ err = modify_user_hw_breakpoint(bp, &attr);
+ }
+
+ return err;
+}
+
+/*
+ * Handle PTRACE_POKEUSR calls for the debug register area.
+ */
+static int ptrace_set_debugreg(struct task_struct *tsk, int n,
+ unsigned long val)
+{
+ struct thread_struct *thread = &tsk->thread;
+ /* There are no DR4 or DR5 registers */
+ int rc = -EIO;
+
+ if (n < HBP_NUM) {
+ rc = ptrace_set_breakpoint_addr(tsk, n, val);
+ } else if (n == 6) {
+ thread->virtual_dr6 = val ^ DR6_RESERVED; /* Flip to positive polarity */
+ rc = 0;
+ } else if (n == 7) {
+ rc = ptrace_write_dr7(tsk, val);
+ if (!rc)
+ thread->ptrace_dr7 = val;
+ }
+ return rc;
+}
+
+/*
+ * These access the current or another (stopped) task's io permission
+ * bitmap for debugging or core dump.
+ */
+static int ioperm_active(struct task_struct *target,
+ const struct user_regset *regset)
+{
+ struct io_bitmap *iobm = target->thread.io_bitmap;
+
+ return iobm ? DIV_ROUND_UP(iobm->max, regset->size) : 0;
+}
+
+static int ioperm_get(struct task_struct *target,
+ const struct user_regset *regset,
+ struct membuf to)
+{
+ struct io_bitmap *iobm = target->thread.io_bitmap;
+
+ if (!iobm)
+ return -ENXIO;
+
+ return membuf_write(&to, iobm->bitmap, IO_BITMAP_BYTES);
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure the single step bit is not set.
+ */
+void ptrace_disable(struct task_struct *child)
+{
+ user_disable_single_step(child);
+}
+
+#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
+static const struct user_regset_view user_x86_32_view; /* Initialized below. */
+#endif
+#ifdef CONFIG_X86_64
+static const struct user_regset_view user_x86_64_view; /* Initialized below. */
+#endif
+
+long arch_ptrace(struct task_struct *child, long request,
+ unsigned long addr, unsigned long data)
+{
+ int ret;
+ unsigned long __user *datap = (unsigned long __user *)data;
+
+#ifdef CONFIG_X86_64
+ /* This is native 64-bit ptrace() */
+ const struct user_regset_view *regset_view = &user_x86_64_view;
+#else
+ /* This is native 32-bit ptrace() */
+ const struct user_regset_view *regset_view = &user_x86_32_view;
+#endif
+
+ switch (request) {
+ /* read the word at location addr in the USER area. */
+ case PTRACE_PEEKUSR: {
+ unsigned long tmp;
+
+ ret = -EIO;
+ if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
+ break;
+
+ tmp = 0; /* Default return condition */
+ if (addr < sizeof(struct user_regs_struct))
+ tmp = getreg(child, addr);
+ else if (addr >= offsetof(struct user, u_debugreg[0]) &&
+ addr <= offsetof(struct user, u_debugreg[7])) {
+ addr -= offsetof(struct user, u_debugreg[0]);
+ tmp = ptrace_get_debugreg(child, addr / sizeof(data));
+ }
+ ret = put_user(tmp, datap);
+ break;
+ }
+
+ case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
+ ret = -EIO;
+ if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
+ break;
+
+ if (addr < sizeof(struct user_regs_struct))
+ ret = putreg(child, addr, data);
+ else if (addr >= offsetof(struct user, u_debugreg[0]) &&
+ addr <= offsetof(struct user, u_debugreg[7])) {
+ addr -= offsetof(struct user, u_debugreg[0]);
+ ret = ptrace_set_debugreg(child,
+ addr / sizeof(data), data);
+ }
+ break;
+
+ case PTRACE_GETREGS: /* Get all gp regs from the child. */
+ return copy_regset_to_user(child,
+ regset_view,
+ REGSET_GENERAL,
+ 0, sizeof(struct user_regs_struct),
+ datap);
+
+ case PTRACE_SETREGS: /* Set all gp regs in the child. */
+ return copy_regset_from_user(child,
+ regset_view,
+ REGSET_GENERAL,
+ 0, sizeof(struct user_regs_struct),
+ datap);
+
+ case PTRACE_GETFPREGS: /* Get the child FPU state. */
+ return copy_regset_to_user(child,
+ regset_view,
+ REGSET_FP,
+ 0, sizeof(struct user_i387_struct),
+ datap);
+
+ case PTRACE_SETFPREGS: /* Set the child FPU state. */
+ return copy_regset_from_user(child,
+ regset_view,
+ REGSET_FP,
+ 0, sizeof(struct user_i387_struct),
+ datap);
+
+#ifdef CONFIG_X86_32
+ case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
+ return copy_regset_to_user(child, &user_x86_32_view,
+ REGSET32_XFP,
+ 0, sizeof(struct user_fxsr_struct),
+ datap) ? -EIO : 0;
+
+ case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
+ return copy_regset_from_user(child, &user_x86_32_view,
+ REGSET32_XFP,
+ 0, sizeof(struct user_fxsr_struct),
+ datap) ? -EIO : 0;
+#endif
+
+#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
+ case PTRACE_GET_THREAD_AREA:
+ if ((int) addr < 0)
+ return -EIO;
+ ret = do_get_thread_area(child, addr,
+ (struct user_desc __user *)data);
+ break;
+
+ case PTRACE_SET_THREAD_AREA:
+ if ((int) addr < 0)
+ return -EIO;
+ ret = do_set_thread_area(child, addr,
+ (struct user_desc __user *)data, 0);
+ break;
+#endif
+
+#ifdef CONFIG_X86_64
+ /* normal 64bit interface to access TLS data.
+ Works just like arch_prctl, except that the arguments
+ are reversed. */
+ case PTRACE_ARCH_PRCTL:
+ ret = do_arch_prctl_64(child, data, addr);
+ break;
+#endif
+
+ default:
+ ret = ptrace_request(child, request, addr, data);
+ break;
+ }
+
+ return ret;
+}
+
+#ifdef CONFIG_IA32_EMULATION
+
+#include <linux/compat.h>
+#include <linux/syscalls.h>
+#include <asm/ia32.h>
+#include <asm/user32.h>
+
+#define R32(l,q) \
+ case offsetof(struct user32, regs.l): \
+ regs->q = value; break
+
+#define SEG32(rs) \
+ case offsetof(struct user32, regs.rs): \
+ return set_segment_reg(child, \
+ offsetof(struct user_regs_struct, rs), \
+ value); \
+ break
+
+static int putreg32(struct task_struct *child, unsigned regno, u32 value)
+{
+ struct pt_regs *regs = task_pt_regs(child);
+ int ret;
+
+ switch (regno) {
+
+ SEG32(cs);
+ SEG32(ds);
+ SEG32(es);
+
+ /*
+ * A 32-bit ptracer on a 64-bit kernel expects that writing
+ * FS or GS will also update the base. This is needed for
+ * operations like PTRACE_SETREGS to fully restore a saved
+ * CPU state.
+ */
+
+ case offsetof(struct user32, regs.fs):
+ ret = set_segment_reg(child,
+ offsetof(struct user_regs_struct, fs),
+ value);
+ if (ret == 0)
+ child->thread.fsbase =
+ x86_fsgsbase_read_task(child, value);
+ return ret;
+
+ case offsetof(struct user32, regs.gs):
+ ret = set_segment_reg(child,
+ offsetof(struct user_regs_struct, gs),
+ value);
+ if (ret == 0)
+ child->thread.gsbase =
+ x86_fsgsbase_read_task(child, value);
+ return ret;
+
+ SEG32(ss);
+
+ R32(ebx, bx);
+ R32(ecx, cx);
+ R32(edx, dx);
+ R32(edi, di);
+ R32(esi, si);
+ R32(ebp, bp);
+ R32(eax, ax);
+ R32(eip, ip);
+ R32(esp, sp);
+
+ case offsetof(struct user32, regs.orig_eax):
+ /*
+ * Warning: bizarre corner case fixup here. A 32-bit
+ * debugger setting orig_eax to -1 wants to disable
+ * syscall restart. Make sure that the syscall
+ * restart code sign-extends orig_ax. Also make sure
+ * we interpret the -ERESTART* codes correctly if
+ * loaded into regs->ax in case the task is not
+ * actually still sitting at the exit from a 32-bit
+ * syscall with TS_COMPAT still set.
+ */
+ regs->orig_ax = value;
+ if (syscall_get_nr(child, regs) != -1)
+ child->thread_info.status |= TS_I386_REGS_POKED;
+ break;
+
+ case offsetof(struct user32, regs.eflags):
+ return set_flags(child, value);
+
+ case offsetof(struct user32, u_debugreg[0]) ...
+ offsetof(struct user32, u_debugreg[7]):
+ regno -= offsetof(struct user32, u_debugreg[0]);
+ return ptrace_set_debugreg(child, regno / 4, value);
+
+ default:
+ if (regno > sizeof(struct user32) || (regno & 3))
+ return -EIO;
+
+ /*
+ * Other dummy fields in the virtual user structure
+ * are ignored
+ */
+ break;
+ }
+ return 0;
+}
+
+#undef R32
+#undef SEG32
+
+#define R32(l,q) \
+ case offsetof(struct user32, regs.l): \
+ *val = regs->q; break
+
+#define SEG32(rs) \
+ case offsetof(struct user32, regs.rs): \
+ *val = get_segment_reg(child, \
+ offsetof(struct user_regs_struct, rs)); \
+ break
+
+static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
+{
+ struct pt_regs *regs = task_pt_regs(child);
+
+ switch (regno) {
+
+ SEG32(ds);
+ SEG32(es);
+ SEG32(fs);
+ SEG32(gs);
+
+ R32(cs, cs);
+ R32(ss, ss);
+ R32(ebx, bx);
+ R32(ecx, cx);
+ R32(edx, dx);
+ R32(edi, di);
+ R32(esi, si);
+ R32(ebp, bp);
+ R32(eax, ax);
+ R32(orig_eax, orig_ax);
+ R32(eip, ip);
+ R32(esp, sp);
+
+ case offsetof(struct user32, regs.eflags):
+ *val = get_flags(child);
+ break;
+
+ case offsetof(struct user32, u_debugreg[0]) ...
+ offsetof(struct user32, u_debugreg[7]):
+ regno -= offsetof(struct user32, u_debugreg[0]);
+ *val = ptrace_get_debugreg(child, regno / 4);
+ break;
+
+ default:
+ if (regno > sizeof(struct user32) || (regno & 3))
+ return -EIO;
+
+ /*
+ * Other dummy fields in the virtual user structure
+ * are ignored
+ */
+ *val = 0;
+ break;
+ }
+ return 0;
+}
+
+#undef R32
+#undef SEG32
+
+static int genregs32_get(struct task_struct *target,
+ const struct user_regset *regset,
+ struct membuf to)
+{
+ int reg;
+
+ for (reg = 0; to.left; reg++) {
+ u32 val;
+ getreg32(target, reg * 4, &val);
+ membuf_store(&to, val);
+ }
+ return 0;
+}
+
+static int genregs32_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 = 0;
+ if (kbuf) {
+ const compat_ulong_t *k = kbuf;
+ while (count >= sizeof(*k) && !ret) {
+ ret = putreg32(target, pos, *k++);
+ count -= sizeof(*k);
+ pos += sizeof(*k);
+ }
+ } else {
+ const compat_ulong_t __user *u = ubuf;
+ while (count >= sizeof(*u) && !ret) {
+ compat_ulong_t word;
+ ret = __get_user(word, u++);
+ if (ret)
+ break;
+ ret = putreg32(target, pos, word);
+ count -= sizeof(*u);
+ pos += sizeof(*u);
+ }
+ }
+ return ret;
+}
+
+static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
+ compat_ulong_t caddr, compat_ulong_t cdata)
+{
+ unsigned long addr = caddr;
+ unsigned long data = cdata;
+ void __user *datap = compat_ptr(data);
+ int ret;
+ __u32 val;
+
+ switch (request) {
+ case PTRACE_PEEKUSR:
+ ret = getreg32(child, addr, &val);
+ if (ret == 0)
+ ret = put_user(val, (__u32 __user *)datap);
+ break;
+
+ case PTRACE_POKEUSR:
+ ret = putreg32(child, addr, data);
+ break;
+
+ case PTRACE_GETREGS: /* Get all gp regs from the child. */
+ return copy_regset_to_user(child, &user_x86_32_view,
+ REGSET_GENERAL,
+ 0, sizeof(struct user_regs_struct32),
+ datap);
+
+ case PTRACE_SETREGS: /* Set all gp regs in the child. */
+ return copy_regset_from_user(child, &user_x86_32_view,
+ REGSET_GENERAL, 0,
+ sizeof(struct user_regs_struct32),
+ datap);
+
+ case PTRACE_GETFPREGS: /* Get the child FPU state. */
+ return copy_regset_to_user(child, &user_x86_32_view,
+ REGSET_FP, 0,
+ sizeof(struct user_i387_ia32_struct),
+ datap);
+
+ case PTRACE_SETFPREGS: /* Set the child FPU state. */
+ return copy_regset_from_user(
+ child, &user_x86_32_view, REGSET_FP,
+ 0, sizeof(struct user_i387_ia32_struct), datap);
+
+ case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
+ return copy_regset_to_user(child, &user_x86_32_view,
+ REGSET32_XFP, 0,
+ sizeof(struct user32_fxsr_struct),
+ datap);
+
+ case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
+ return copy_regset_from_user(child, &user_x86_32_view,
+ REGSET32_XFP, 0,
+ sizeof(struct user32_fxsr_struct),
+ datap);
+
+ case PTRACE_GET_THREAD_AREA:
+ case PTRACE_SET_THREAD_AREA:
+ return arch_ptrace(child, request, addr, data);
+
+ default:
+ return compat_ptrace_request(child, request, addr, data);
+ }
+
+ return ret;
+}
+#endif /* CONFIG_IA32_EMULATION */
+
+#ifdef CONFIG_X86_X32_ABI
+static long x32_arch_ptrace(struct task_struct *child,
+ compat_long_t request, compat_ulong_t caddr,
+ compat_ulong_t cdata)
+{
+ unsigned long addr = caddr;
+ unsigned long data = cdata;
+ void __user *datap = compat_ptr(data);
+ int ret;
+
+ switch (request) {
+ /* Read 32bits at location addr in the USER area. Only allow
+ to return the lower 32bits of segment and debug registers. */
+ case PTRACE_PEEKUSR: {
+ u32 tmp;
+
+ ret = -EIO;
+ if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
+ addr < offsetof(struct user_regs_struct, cs))
+ break;
+
+ tmp = 0; /* Default return condition */
+ if (addr < sizeof(struct user_regs_struct))
+ tmp = getreg(child, addr);
+ else if (addr >= offsetof(struct user, u_debugreg[0]) &&
+ addr <= offsetof(struct user, u_debugreg[7])) {
+ addr -= offsetof(struct user, u_debugreg[0]);
+ tmp = ptrace_get_debugreg(child, addr / sizeof(data));
+ }
+ ret = put_user(tmp, (__u32 __user *)datap);
+ break;
+ }
+
+ /* Write the word at location addr in the USER area. Only allow
+ to update segment and debug registers with the upper 32bits
+ zero-extended. */
+ case PTRACE_POKEUSR:
+ ret = -EIO;
+ if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
+ addr < offsetof(struct user_regs_struct, cs))
+ break;
+
+ if (addr < sizeof(struct user_regs_struct))
+ ret = putreg(child, addr, data);
+ else if (addr >= offsetof(struct user, u_debugreg[0]) &&
+ addr <= offsetof(struct user, u_debugreg[7])) {
+ addr -= offsetof(struct user, u_debugreg[0]);
+ ret = ptrace_set_debugreg(child,
+ addr / sizeof(data), data);
+ }
+ break;
+
+ case PTRACE_GETREGS: /* Get all gp regs from the child. */
+ return copy_regset_to_user(child,
+ &user_x86_64_view,
+ REGSET_GENERAL,
+ 0, sizeof(struct user_regs_struct),
+ datap);
+
+ case PTRACE_SETREGS: /* Set all gp regs in the child. */
+ return copy_regset_from_user(child,
+ &user_x86_64_view,
+ REGSET_GENERAL,
+ 0, sizeof(struct user_regs_struct),
+ datap);
+
+ case PTRACE_GETFPREGS: /* Get the child FPU state. */
+ return copy_regset_to_user(child,
+ &user_x86_64_view,
+ REGSET_FP,
+ 0, sizeof(struct user_i387_struct),
+ datap);
+
+ case PTRACE_SETFPREGS: /* Set the child FPU state. */
+ return copy_regset_from_user(child,
+ &user_x86_64_view,
+ REGSET_FP,
+ 0, sizeof(struct user_i387_struct),
+ datap);
+
+ default:
+ return compat_ptrace_request(child, request, addr, data);
+ }
+
+ return ret;
+}
+#endif
+
+#ifdef CONFIG_COMPAT
+long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
+ compat_ulong_t caddr, compat_ulong_t cdata)
+{
+#ifdef CONFIG_X86_X32_ABI
+ if (!in_ia32_syscall())
+ return x32_arch_ptrace(child, request, caddr, cdata);
+#endif
+#ifdef CONFIG_IA32_EMULATION
+ return ia32_arch_ptrace(child, request, caddr, cdata);
+#else
+ return 0;
+#endif
+}
+#endif /* CONFIG_COMPAT */
+
+#ifdef CONFIG_X86_64
+
+static struct user_regset x86_64_regsets[] __ro_after_init = {
+ [REGSET64_GENERAL] = {
+ .core_note_type = NT_PRSTATUS,
+ .n = sizeof(struct user_regs_struct) / sizeof(long),
+ .size = sizeof(long),
+ .align = sizeof(long),
+ .regset_get = genregs_get,
+ .set = genregs_set
+ },
+ [REGSET64_FP] = {
+ .core_note_type = NT_PRFPREG,
+ .n = sizeof(struct fxregs_state) / sizeof(long),
+ .size = sizeof(long),
+ .align = sizeof(long),
+ .active = regset_xregset_fpregs_active,
+ .regset_get = xfpregs_get,
+ .set = xfpregs_set
+ },
+ [REGSET64_XSTATE] = {
+ .core_note_type = NT_X86_XSTATE,
+ .size = sizeof(u64),
+ .align = sizeof(u64),
+ .active = xstateregs_active,
+ .regset_get = xstateregs_get,
+ .set = xstateregs_set
+ },
+ [REGSET64_IOPERM] = {
+ .core_note_type = NT_386_IOPERM,
+ .n = IO_BITMAP_LONGS,
+ .size = sizeof(long),
+ .align = sizeof(long),
+ .active = ioperm_active,
+ .regset_get = ioperm_get
+ },
+#ifdef CONFIG_X86_USER_SHADOW_STACK
+ [REGSET64_SSP] = {
+ .core_note_type = NT_X86_SHSTK,
+ .n = 1,
+ .size = sizeof(u64),
+ .align = sizeof(u64),
+ .active = ssp_active,
+ .regset_get = ssp_get,
+ .set = ssp_set
+ },
+#endif
+};
+
+static const struct user_regset_view user_x86_64_view = {
+ .name = "x86_64", .e_machine = EM_X86_64,
+ .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
+};
+
+#else /* CONFIG_X86_32 */
+
+#define user_regs_struct32 user_regs_struct
+#define genregs32_get genregs_get
+#define genregs32_set genregs_set
+
+#endif /* CONFIG_X86_64 */
+
+#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
+static struct user_regset x86_32_regsets[] __ro_after_init = {
+ [REGSET32_GENERAL] = {
+ .core_note_type = NT_PRSTATUS,
+ .n = sizeof(struct user_regs_struct32) / sizeof(u32),
+ .size = sizeof(u32),
+ .align = sizeof(u32),
+ .regset_get = genregs32_get,
+ .set = genregs32_set
+ },
+ [REGSET32_FP] = {
+ .core_note_type = NT_PRFPREG,
+ .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
+ .size = sizeof(u32),
+ .align = sizeof(u32),
+ .active = regset_fpregs_active,
+ .regset_get = fpregs_get,
+ .set = fpregs_set
+ },
+ [REGSET32_XFP] = {
+ .core_note_type = NT_PRXFPREG,
+ .n = sizeof(struct fxregs_state) / sizeof(u32),
+ .size = sizeof(u32),
+ .align = sizeof(u32),
+ .active = regset_xregset_fpregs_active,
+ .regset_get = xfpregs_get,
+ .set = xfpregs_set
+ },
+ [REGSET32_XSTATE] = {
+ .core_note_type = NT_X86_XSTATE,
+ .size = sizeof(u64),
+ .align = sizeof(u64),
+ .active = xstateregs_active,
+ .regset_get = xstateregs_get,
+ .set = xstateregs_set
+ },
+ [REGSET32_TLS] = {
+ .core_note_type = NT_386_TLS,
+ .n = GDT_ENTRY_TLS_ENTRIES,
+ .bias = GDT_ENTRY_TLS_MIN,
+ .size = sizeof(struct user_desc),
+ .align = sizeof(struct user_desc),
+ .active = regset_tls_active,
+ .regset_get = regset_tls_get,
+ .set = regset_tls_set
+ },
+ [REGSET32_IOPERM] = {
+ .core_note_type = NT_386_IOPERM,
+ .n = IO_BITMAP_BYTES / sizeof(u32),
+ .size = sizeof(u32),
+ .align = sizeof(u32),
+ .active = ioperm_active,
+ .regset_get = ioperm_get
+ },
+};
+
+static const struct user_regset_view user_x86_32_view = {
+ .name = "i386", .e_machine = EM_386,
+ .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
+};
+#endif
+
+/*
+ * This represents bytes 464..511 in the memory layout exported through
+ * the REGSET_XSTATE interface.
+ */
+u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
+
+void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
+{
+#ifdef CONFIG_X86_64
+ x86_64_regsets[REGSET64_XSTATE].n = size / sizeof(u64);
+#endif
+#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
+ x86_32_regsets[REGSET32_XSTATE].n = size / sizeof(u64);
+#endif
+ xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
+}
+
+/*
+ * This is used by the core dump code to decide which regset to dump. The
+ * core dump code writes out the resulting .e_machine and the corresponding
+ * regsets. This is suboptimal if the task is messing around with its CS.L
+ * field, but at worst the core dump will end up missing some information.
+ *
+ * Unfortunately, it is also used by the broken PTRACE_GETREGSET and
+ * PTRACE_SETREGSET APIs. These APIs look at the .regsets field but have
+ * no way to make sure that the e_machine they use matches the caller's
+ * expectations. The result is that the data format returned by
+ * PTRACE_GETREGSET depends on the returned CS field (and even the offset
+ * of the returned CS field depends on its value!) and the data format
+ * accepted by PTRACE_SETREGSET is determined by the old CS value. The
+ * upshot is that it is basically impossible to use these APIs correctly.
+ *
+ * The best way to fix it in the long run would probably be to add new
+ * improved ptrace() APIs to read and write registers reliably, possibly by
+ * allowing userspace to select the ELF e_machine variant that they expect.
+ */
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+#ifdef CONFIG_IA32_EMULATION
+ if (!user_64bit_mode(task_pt_regs(task)))
+#endif
+#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
+ return &user_x86_32_view;
+#endif
+#ifdef CONFIG_X86_64
+ return &user_x86_64_view;
+#endif
+}
+
+void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
+{
+ struct task_struct *tsk = current;
+
+ tsk->thread.trap_nr = X86_TRAP_DB;
+ tsk->thread.error_code = error_code;
+
+ /* Send us the fake SIGTRAP */
+ force_sig_fault(SIGTRAP, si_code,
+ user_mode(regs) ? (void __user *)regs->ip : NULL);
+}
+
+void user_single_step_report(struct pt_regs *regs)
+{
+ send_sigtrap(regs, 0, TRAP_BRKPT);
+}