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-rw-r--r--arch/x86/kernel/ptrace.c428
1 files changed, 237 insertions, 191 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 4b8ee05dd6ad..3dcadc13f09a 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/* By Ross Biro 1/23/92 */
/*
* Pentium III FXSR, SSE support
@@ -12,7 +13,6 @@
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/ptrace.h>
-#include <linux/tracehook.h>
#include <linux/user.h>
#include <linux/elf.h>
#include <linux/security.h>
@@ -24,13 +24,13 @@
#include <linux/rcupdate.h>
#include <linux/export.h>
#include <linux/context_tracking.h>
+#include <linux/nospec.h>
#include <linux/uaccess.h>
-#include <asm/pgtable.h>
#include <asm/processor.h>
-#include <asm/fpu/internal.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>
@@ -40,19 +40,40 @@
#include <asm/traps.h>
#include <asm/syscall.h>
#include <asm/fsgsbase.h>
+#include <asm/io_bitmap.h>
#include "tls.h"
-enum x86_regset {
- REGSET_GENERAL,
- REGSET_FP,
- REGSET_XFP,
- REGSET_IOPERM64 = REGSET_XFP,
- REGSET_XSTATE,
- REGSET_TLS,
- REGSET_IOPERM32,
+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;
@@ -153,35 +174,6 @@ static inline bool invalid_selector(u16 value)
#define FLAG_MASK FLAG_MASK_32
-/*
- * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
- * when it traps. The previous stack will be directly underneath the saved
- * registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
- *
- * Now, if the stack is empty, '&regs->sp' is out of range. In this
- * case we try to take the previous stack. To always return a non-null
- * stack pointer we fall back to regs as stack if no previous stack
- * exists.
- *
- * This is valid only for kernel mode traps.
- */
-unsigned long kernel_stack_pointer(struct pt_regs *regs)
-{
- unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
- unsigned long sp = (unsigned long)&regs->sp;
- u32 *prev_esp;
-
- if (context == (sp & ~(THREAD_SIZE - 1)))
- return sp;
-
- prev_esp = (u32 *)(context);
- if (*prev_esp)
- return (unsigned long)*prev_esp;
-
- return (unsigned long)regs;
-}
-EXPORT_SYMBOL_GPL(kernel_stack_pointer);
-
static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
{
BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
@@ -198,9 +190,9 @@ static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
retval = *pt_regs_access(task_pt_regs(task), offset);
else {
if (task == current)
- retval = get_user_gs(task_pt_regs(task));
+ savesegment(gs, retval);
else
- retval = task_user_gs(task);
+ retval = task->thread.gs;
}
return retval;
}
@@ -208,6 +200,9 @@ static u16 get_segment_reg(struct task_struct *task, unsigned long 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.
*/
@@ -228,16 +223,14 @@ static int set_segment_reg(struct task_struct *task,
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):
- if (task == current)
- set_user_gs(task_pt_regs(task), value);
- else
- task_user_gs(task) = value;
+ task->thread.gs = value;
}
return 0;
@@ -297,32 +290,33 @@ static u16 get_segment_reg(struct task_struct *task, unsigned long 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;
- if (task == current)
- loadsegment(fs, task->thread.fsindex);
break;
case offsetof(struct user_regs_struct,gs):
task->thread.gsindex = value;
- if (task == current)
- load_gs_index(task->thread.gsindex);
break;
case offsetof(struct user_regs_struct,ds):
task->thread.ds = value;
- if (task == current)
- loadsegment(ds, task->thread.ds);
break;
case offsetof(struct user_regs_struct,es):
task->thread.es = value;
- if (task == current)
- loadsegment(es, task->thread.es);
break;
/*
@@ -396,22 +390,12 @@ static int putreg(struct task_struct *child,
case offsetof(struct user_regs_struct,fs_base):
if (value >= TASK_SIZE_MAX)
return -EIO;
- /*
- * When changing the FS base, use do_arch_prctl_64()
- * to set the index to zero and to set the base
- * as requested.
- */
- if (child->thread.fsbase != value)
- return do_arch_prctl_64(child, ARCH_SET_FS, value);
+ x86_fsbase_write_task(child, value);
return 0;
case offsetof(struct user_regs_struct,gs_base):
- /*
- * Exactly the same here as the %fs handling above.
- */
if (value >= TASK_SIZE_MAX)
return -EIO;
- if (child->thread.gsbase != value)
- return do_arch_prctl_64(child, ARCH_SET_GS, value);
+ x86_gsbase_write_task(child, value);
return 0;
#endif
}
@@ -447,26 +431,12 @@ static unsigned long getreg(struct task_struct *task, unsigned long offset)
static int genregs_get(struct task_struct *target,
const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf)
+ struct membuf to)
{
- if (kbuf) {
- unsigned long *k = kbuf;
- while (count >= sizeof(*k)) {
- *k++ = getreg(target, pos);
- count -= sizeof(*k);
- pos += sizeof(*k);
- }
- } else {
- unsigned long __user *u = ubuf;
- while (count >= sizeof(*u)) {
- if (__put_user(getreg(target, pos), u++))
- return -EFAULT;
- count -= sizeof(*u);
- pos += sizeof(*u);
- }
- }
+ int reg;
+ for (reg = 0; to.left; reg++)
+ membuf_store(&to, getreg(target, reg * sizeof(unsigned long)));
return 0;
}
@@ -514,7 +484,7 @@ static void ptrace_triggered(struct perf_event *bp,
break;
}
- thread->debugreg6 |= (DR_TRAP0 << i);
+ thread->virtual_dr6 |= (DR_TRAP0 << i);
}
/*
@@ -644,12 +614,13 @@ static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
unsigned long val = 0;
if (n < HBP_NUM) {
- struct perf_event *bp = thread->ptrace_bps[n];
+ 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->debugreg6;
+ val = thread->virtual_dr6 ^ DR6_RESERVED; /* Flip back to arch polarity */
} else if (n == 7) {
val = thread->ptrace_dr7;
}
@@ -705,7 +676,7 @@ static int ptrace_set_debugreg(struct task_struct *tsk, int n,
if (n < HBP_NUM) {
rc = ptrace_set_breakpoint_addr(tsk, n, val);
} else if (n == 6) {
- thread->debugreg6 = val;
+ thread->virtual_dr6 = val ^ DR6_RESERVED; /* Flip to positive polarity */
rc = 0;
} else if (n == 7) {
rc = ptrace_write_dr7(tsk, val);
@@ -722,20 +693,21 @@ static int ptrace_set_debugreg(struct task_struct *tsk, int n,
static int ioperm_active(struct task_struct *target,
const struct user_regset *regset)
{
- return target->thread.io_bitmap_max / regset->size;
+ 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,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf)
+ struct membuf to)
{
- if (!target->thread.io_bitmap_ptr)
+ struct io_bitmap *iobm = target->thread.io_bitmap;
+
+ if (!iobm)
return -ENXIO;
- return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
- target->thread.io_bitmap_ptr,
- 0, IO_BITMAP_BYTES);
+ return membuf_write(&to, iobm->bitmap, IO_BITMAP_BYTES);
}
/*
@@ -746,14 +718,14 @@ static int ioperm_get(struct task_struct *target,
void ptrace_disable(struct task_struct *child)
{
user_disable_single_step(child);
-#ifdef TIF_SYSCALL_EMU
- clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
-#endif
}
#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)
@@ -761,6 +733,14 @@ long arch_ptrace(struct task_struct *child, long request,
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: {
@@ -799,28 +779,28 @@ long arch_ptrace(struct task_struct *child, long request,
case PTRACE_GETREGS: /* Get all gp regs from the child. */
return copy_regset_to_user(child,
- task_user_regset_view(current),
+ 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,
- task_user_regset_view(current),
+ 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,
- task_user_regset_view(current),
+ 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,
- task_user_regset_view(current),
+ regset_view,
REGSET_FP,
0, sizeof(struct user_i387_struct),
datap);
@@ -828,13 +808,13 @@ long arch_ptrace(struct task_struct *child, long request,
#ifdef CONFIG_X86_32
case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
return copy_regset_to_user(child, &user_x86_32_view,
- REGSET_XFP,
+ 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,
- REGSET_XFP,
+ REGSET32_XFP,
0, sizeof(struct user_fxsr_struct),
datap) ? -EIO : 0;
#endif
@@ -893,14 +873,39 @@ long arch_ptrace(struct task_struct *child, long request,
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);
- SEG32(fs);
- SEG32(gs);
+
+ /*
+ * 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);
@@ -925,7 +930,7 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 value)
* syscall with TS_COMPAT still set.
*/
regs->orig_ax = value;
- if (syscall_get_nr(child, regs) >= 0)
+ if (syscall_get_nr(child, regs) != -1)
child->thread_info.status |= TS_I386_REGS_POKED;
break;
@@ -1016,28 +1021,15 @@ static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
static int genregs32_get(struct task_struct *target,
const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf)
+ struct membuf to)
{
- if (kbuf) {
- compat_ulong_t *k = kbuf;
- while (count >= sizeof(*k)) {
- getreg32(target, pos, k++);
- count -= sizeof(*k);
- pos += sizeof(*k);
- }
- } else {
- compat_ulong_t __user *u = ubuf;
- while (count >= sizeof(*u)) {
- compat_ulong_t word;
- getreg32(target, pos, &word);
- if (__put_user(word, u++))
- return -EFAULT;
- count -= sizeof(*u);
- pos += sizeof(*u);
- }
- }
+ int reg;
+ for (reg = 0; to.left; reg++) {
+ u32 val;
+ getreg32(target, reg * 4, &val);
+ membuf_store(&to, val);
+ }
return 0;
}
@@ -1114,13 +1106,13 @@ static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
return copy_regset_to_user(child, &user_x86_32_view,
- REGSET_XFP, 0,
+ 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,
- REGSET_XFP, 0,
+ REGSET32_XFP, 0,
sizeof(struct user32_fxsr_struct),
datap);
@@ -1190,28 +1182,28 @@ static long x32_arch_ptrace(struct task_struct *child,
case PTRACE_GETREGS: /* Get all gp regs from the child. */
return copy_regset_to_user(child,
- task_user_regset_view(current),
+ &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,
- task_user_regset_view(current),
+ &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,
- task_user_regset_view(current),
+ &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,
- task_user_regset_view(current),
+ &user_x86_64_view,
REGSET_FP,
0, sizeof(struct user_i387_struct),
datap);
@@ -1243,30 +1235,50 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
#ifdef CONFIG_X86_64
static struct user_regset x86_64_regsets[] __ro_after_init = {
- [REGSET_GENERAL] = {
- .core_note_type = NT_PRSTATUS,
- .n = sizeof(struct user_regs_struct) / sizeof(long),
- .size = sizeof(long), .align = sizeof(long),
- .get = genregs_get, .set = genregs_set
+ [REGSET64_GENERAL] = {
+ USER_REGSET_NOTE_TYPE(PRSTATUS),
+ .n = sizeof(struct user_regs_struct) / sizeof(long),
+ .size = sizeof(long),
+ .align = sizeof(long),
+ .regset_get = genregs_get,
+ .set = genregs_set
},
- [REGSET_FP] = {
- .core_note_type = NT_PRFPREG,
- .n = sizeof(struct user_i387_struct) / sizeof(long),
- .size = sizeof(long), .align = sizeof(long),
- .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
+ [REGSET64_FP] = {
+ USER_REGSET_NOTE_TYPE(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
},
- [REGSET_XSTATE] = {
- .core_note_type = NT_X86_XSTATE,
- .size = sizeof(u64), .align = sizeof(u64),
- .active = xstateregs_active, .get = xstateregs_get,
- .set = xstateregs_set
+ [REGSET64_XSTATE] = {
+ USER_REGSET_NOTE_TYPE(X86_XSTATE),
+ .size = sizeof(u64),
+ .align = sizeof(u64),
+ .active = xstateregs_active,
+ .regset_get = xstateregs_get,
+ .set = xstateregs_set
},
- [REGSET_IOPERM64] = {
- .core_note_type = NT_386_IOPERM,
- .n = IO_BITMAP_LONGS,
- .size = sizeof(long), .align = sizeof(long),
- .active = ioperm_active, .get = ioperm_get
+ [REGSET64_IOPERM] = {
+ USER_REGSET_NOTE_TYPE(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] = {
+ USER_REGSET_NOTE_TYPE(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 = {
@@ -1284,43 +1296,57 @@ static const struct user_regset_view user_x86_64_view = {
#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
static struct user_regset x86_32_regsets[] __ro_after_init = {
- [REGSET_GENERAL] = {
- .core_note_type = NT_PRSTATUS,
- .n = sizeof(struct user_regs_struct32) / sizeof(u32),
- .size = sizeof(u32), .align = sizeof(u32),
- .get = genregs32_get, .set = genregs32_set
+ [REGSET32_GENERAL] = {
+ USER_REGSET_NOTE_TYPE(PRSTATUS),
+ .n = sizeof(struct user_regs_struct32) / sizeof(u32),
+ .size = sizeof(u32),
+ .align = sizeof(u32),
+ .regset_get = genregs32_get,
+ .set = genregs32_set
},
- [REGSET_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, .get = fpregs_get, .set = fpregs_set
+ [REGSET32_FP] = {
+ USER_REGSET_NOTE_TYPE(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
},
- [REGSET_XFP] = {
- .core_note_type = NT_PRXFPREG,
- .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
- .size = sizeof(u32), .align = sizeof(u32),
- .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
+ [REGSET32_XFP] = {
+ USER_REGSET_NOTE_TYPE(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
},
- [REGSET_XSTATE] = {
- .core_note_type = NT_X86_XSTATE,
- .size = sizeof(u64), .align = sizeof(u64),
- .active = xstateregs_active, .get = xstateregs_get,
- .set = xstateregs_set
+ [REGSET32_XSTATE] = {
+ USER_REGSET_NOTE_TYPE(X86_XSTATE),
+ .size = sizeof(u64),
+ .align = sizeof(u64),
+ .active = xstateregs_active,
+ .regset_get = xstateregs_get,
+ .set = xstateregs_set
},
- [REGSET_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,
- .get = regset_tls_get, .set = regset_tls_set
+ [REGSET32_TLS] = {
+ USER_REGSET_NOTE_TYPE(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
},
- [REGSET_IOPERM32] = {
- .core_note_type = NT_386_IOPERM,
- .n = IO_BITMAP_BYTES / sizeof(u32),
- .size = sizeof(u32), .align = sizeof(u32),
- .active = ioperm_active, .get = ioperm_get
+ [REGSET32_IOPERM] = {
+ USER_REGSET_NOTE_TYPE(386_IOPERM),
+ .n = IO_BITMAP_BYTES / sizeof(u32),
+ .size = sizeof(u32),
+ .align = sizeof(u32),
+ .active = ioperm_active,
+ .regset_get = ioperm_get
},
};
@@ -1339,14 +1365,33 @@ 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[REGSET_XSTATE].n = size / sizeof(u64);
+ x86_64_regsets[REGSET64_XSTATE].n = size / sizeof(u64);
#endif
#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
- x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
+ 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
@@ -1360,18 +1405,19 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task)
#endif
}
-void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
- int error_code, int si_code)
+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, tsk);
+ user_mode(regs) ? (void __user *)regs->ip : NULL);
}
void user_single_step_report(struct pt_regs *regs)
{
- send_sigtrap(current, regs, 0, TRAP_BRKPT);
+ send_sigtrap(regs, 0, TRAP_BRKPT);
}
generated by cgit (git 2.34.1) at 2025-12-25 00:15:50 +0000