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-rw-r--r--arch/x86/um/asm/checksum.h3
-rw-r--r--arch/x86/um/asm/processor.h8
-rw-r--r--arch/x86/um/os-Linux/mcontext.c218
-rw-r--r--arch/x86/um/ptrace.c76
-rw-r--r--arch/x86/um/shared/sysdep/kernel-offsets.h2
-rw-r--r--arch/x86/um/shared/sysdep/mcontext.h9
-rw-r--r--arch/x86/um/shared/sysdep/stub-data.h23
-rw-r--r--arch/x86/um/shared/sysdep/stub.h2
-rw-r--r--arch/x86/um/shared/sysdep/stub_32.h13
-rw-r--r--arch/x86/um/shared/sysdep/stub_64.h17
-rw-r--r--arch/x86/um/tls_32.c26
11 files changed, 366 insertions, 31 deletions
diff --git a/arch/x86/um/asm/checksum.h b/arch/x86/um/asm/checksum.h
index b07824500363..ddc144657efa 100644
--- a/arch/x86/um/asm/checksum.h
+++ b/arch/x86/um/asm/checksum.h
@@ -20,6 +20,9 @@
*/
extern __wsum csum_partial(const void *buff, int len, __wsum sum);
+/* Do not call this directly. Declared for export type visibility. */
+extern __visible __wsum csum_partial_copy_generic(const void *src, void *dst, int len);
+
/**
* csum_fold - Fold and invert a 32bit checksum.
* sum: 32bit unfolded sum
diff --git a/arch/x86/um/asm/processor.h b/arch/x86/um/asm/processor.h
index 478710384b34..e222d2ae28fd 100644
--- a/arch/x86/um/asm/processor.h
+++ b/arch/x86/um/asm/processor.h
@@ -21,10 +21,10 @@
#include <asm/user.h>
-/* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */
-static __always_inline void rep_nop(void)
+/* PAUSE is a good thing to insert into busy-wait loops. */
+static __always_inline void native_pause(void)
{
- __asm__ __volatile__("rep;nop": : :"memory");
+ __asm__ __volatile__("pause": : :"memory");
}
static __always_inline void cpu_relax(void)
@@ -33,7 +33,7 @@ static __always_inline void cpu_relax(void)
time_travel_mode == TT_MODE_EXTERNAL)
time_travel_ndelay(1);
else
- rep_nop();
+ native_pause();
}
#define task_pt_regs(t) (&(t)->thread.regs)
diff --git a/arch/x86/um/os-Linux/mcontext.c b/arch/x86/um/os-Linux/mcontext.c
index 37decaa74761..a21403df6663 100644
--- a/arch/x86/um/os-Linux/mcontext.c
+++ b/arch/x86/um/os-Linux/mcontext.c
@@ -1,7 +1,10 @@
// SPDX-License-Identifier: GPL-2.0
-#include <sys/ucontext.h>
#define __FRAME_OFFSETS
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <sys/ucontext.h>
#include <asm/ptrace.h>
+#include <asm/sigcontext.h>
#include <sysdep/ptrace.h>
#include <sysdep/mcontext.h>
#include <arch.h>
@@ -18,6 +21,10 @@ void get_regs_from_mc(struct uml_pt_regs *regs, mcontext_t *mc)
COPY2(UESP, ESP); /* sic */
COPY(EBX); COPY(EDX); COPY(ECX); COPY(EAX);
COPY(EIP); COPY_SEG_CPL3(CS); COPY(EFL); COPY_SEG_CPL3(SS);
+#undef COPY2
+#undef COPY
+#undef COPY_SEG
+#undef COPY_SEG_CPL3
#else
#define COPY2(X,Y) regs->gp[X/sizeof(unsigned long)] = mc->gregs[REG_##Y]
#define COPY(X) regs->gp[X/sizeof(unsigned long)] = mc->gregs[REG_##X]
@@ -29,6 +36,8 @@ void get_regs_from_mc(struct uml_pt_regs *regs, mcontext_t *mc)
COPY2(EFLAGS, EFL);
COPY2(CS, CSGSFS);
regs->gp[SS / sizeof(unsigned long)] = mc->gregs[REG_CSGSFS] >> 48;
+#undef COPY2
+#undef COPY
#endif
}
@@ -42,3 +51,210 @@ void mc_set_rip(void *_mc, void *target)
mc->gregs[REG_RIP] = (unsigned long)target;
#endif
}
+
+/* Same thing, but the copy macros are turned around. */
+void get_mc_from_regs(struct uml_pt_regs *regs, mcontext_t *mc, int single_stepping)
+{
+#ifdef __i386__
+#define COPY2(X,Y) mc->gregs[REG_##Y] = regs->gp[X]
+#define COPY(X) mc->gregs[REG_##X] = regs->gp[X]
+#define COPY_SEG(X) mc->gregs[REG_##X] = regs->gp[X] & 0xffff;
+#define COPY_SEG_CPL3(X) mc->gregs[REG_##X] = (regs->gp[X] & 0xffff) | 3;
+ COPY_SEG(GS); COPY_SEG(FS); COPY_SEG(ES); COPY_SEG(DS);
+ COPY(EDI); COPY(ESI); COPY(EBP);
+ COPY2(UESP, ESP); /* sic */
+ COPY(EBX); COPY(EDX); COPY(ECX); COPY(EAX);
+ COPY(EIP); COPY_SEG_CPL3(CS); COPY(EFL); COPY_SEG_CPL3(SS);
+#else
+#define COPY2(X,Y) mc->gregs[REG_##Y] = regs->gp[X/sizeof(unsigned long)]
+#define COPY(X) mc->gregs[REG_##X] = regs->gp[X/sizeof(unsigned long)]
+ COPY(R8); COPY(R9); COPY(R10); COPY(R11);
+ COPY(R12); COPY(R13); COPY(R14); COPY(R15);
+ COPY(RDI); COPY(RSI); COPY(RBP); COPY(RBX);
+ COPY(RDX); COPY(RAX); COPY(RCX); COPY(RSP);
+ COPY(RIP);
+ COPY2(EFLAGS, EFL);
+ mc->gregs[REG_CSGSFS] = mc->gregs[REG_CSGSFS] & 0xffffffffffffl;
+ mc->gregs[REG_CSGSFS] |= (regs->gp[SS / sizeof(unsigned long)] & 0xffff) << 48;
+#endif
+
+ if (single_stepping)
+ mc->gregs[REG_EFL] |= X86_EFLAGS_TF;
+ else
+ mc->gregs[REG_EFL] &= ~X86_EFLAGS_TF;
+}
+
+#ifdef CONFIG_X86_32
+struct _xstate_64 {
+ struct _fpstate_64 fpstate;
+ struct _header xstate_hdr;
+ struct _ymmh_state ymmh;
+ /* New processor state extensions go here: */
+};
+
+/* Not quite the right structures as these contain more information */
+int um_i387_from_fxsr(struct _fpstate_32 *i387,
+ const struct _fpstate_64 *fxsave);
+int um_fxsr_from_i387(struct _fpstate_64 *fxsave,
+ const struct _fpstate_32 *from);
+#else
+#define _xstate_64 _xstate
+#endif
+
+static struct _fpstate *get_fpstate(struct stub_data *data,
+ mcontext_t *mcontext,
+ int *fp_size)
+{
+ struct _fpstate *res;
+
+ /* Assume floating point registers are on the same page */
+ res = (void *)(((unsigned long)mcontext->fpregs &
+ (UM_KERN_PAGE_SIZE - 1)) +
+ (unsigned long)&data->sigstack[0]);
+
+ if ((void *)res + sizeof(struct _fpstate) >
+ (void *)data->sigstack + sizeof(data->sigstack))
+ return NULL;
+
+ if (res->sw_reserved.magic1 != FP_XSTATE_MAGIC1) {
+ *fp_size = sizeof(struct _fpstate);
+ } else {
+ char *magic2_addr;
+
+ magic2_addr = (void *)res;
+ magic2_addr += res->sw_reserved.extended_size;
+ magic2_addr -= FP_XSTATE_MAGIC2_SIZE;
+
+ /* We still need to be within our stack */
+ if ((void *)magic2_addr >
+ (void *)data->sigstack + sizeof(data->sigstack))
+ return NULL;
+
+ /* If we do not read MAGIC2, then we did something wrong */
+ if (*(__u32 *)magic2_addr != FP_XSTATE_MAGIC2)
+ return NULL;
+
+ /* Remove MAGIC2 from the size, we do not save/restore it */
+ *fp_size = res->sw_reserved.extended_size -
+ FP_XSTATE_MAGIC2_SIZE;
+ }
+
+ return res;
+}
+
+int get_stub_state(struct uml_pt_regs *regs, struct stub_data *data,
+ unsigned long *fp_size_out)
+{
+ mcontext_t *mcontext;
+ struct _fpstate *fpstate_stub;
+ struct _xstate_64 *xstate_stub;
+ int fp_size, xstate_size;
+
+ /* mctx_offset is verified by wait_stub_done_seccomp */
+ mcontext = (void *)&data->sigstack[data->mctx_offset];
+
+ get_regs_from_mc(regs, mcontext);
+
+ fpstate_stub = get_fpstate(data, mcontext, &fp_size);
+ if (!fpstate_stub)
+ return -EINVAL;
+
+#ifdef CONFIG_X86_32
+ xstate_stub = (void *)&fpstate_stub->_fxsr_env;
+ xstate_size = fp_size - offsetof(struct _fpstate_32, _fxsr_env);
+#else
+ xstate_stub = (void *)fpstate_stub;
+ xstate_size = fp_size;
+#endif
+
+ if (fp_size_out)
+ *fp_size_out = xstate_size;
+
+ if (xstate_size > host_fp_size)
+ return -ENOSPC;
+
+ memcpy(&regs->fp, xstate_stub, xstate_size);
+
+ /* We do not need to read the x86_64 FS_BASE/GS_BASE registers as
+ * we do not permit userspace to set them directly.
+ */
+
+#ifdef CONFIG_X86_32
+ /* Read the i387 legacy FP registers */
+ if (um_fxsr_from_i387((void *)&regs->fp, fpstate_stub))
+ return -EINVAL;
+#endif
+
+ return 0;
+}
+
+/* Copied because we cannot include regset.h here. */
+struct task_struct;
+struct user_regset;
+struct membuf {
+ void *p;
+ size_t left;
+};
+
+int fpregs_legacy_get(struct task_struct *target,
+ const struct user_regset *regset,
+ struct membuf to);
+
+int set_stub_state(struct uml_pt_regs *regs, struct stub_data *data,
+ int single_stepping)
+{
+ mcontext_t *mcontext;
+ struct _fpstate *fpstate_stub;
+ struct _xstate_64 *xstate_stub;
+ int fp_size, xstate_size;
+
+ /* mctx_offset is verified by wait_stub_done_seccomp */
+ mcontext = (void *)&data->sigstack[data->mctx_offset];
+
+ if ((unsigned long)mcontext < (unsigned long)data->sigstack ||
+ (unsigned long)mcontext >
+ (unsigned long) data->sigstack +
+ sizeof(data->sigstack) - sizeof(*mcontext))
+ return -EINVAL;
+
+ get_mc_from_regs(regs, mcontext, single_stepping);
+
+ fpstate_stub = get_fpstate(data, mcontext, &fp_size);
+ if (!fpstate_stub)
+ return -EINVAL;
+
+#ifdef CONFIG_X86_32
+ xstate_stub = (void *)&fpstate_stub->_fxsr_env;
+ xstate_size = fp_size - offsetof(struct _fpstate_32, _fxsr_env);
+#else
+ xstate_stub = (void *)fpstate_stub;
+ xstate_size = fp_size;
+#endif
+
+ memcpy(xstate_stub, &regs->fp, xstate_size);
+
+#ifdef __i386__
+ /*
+ * On x86, the GDT entries are updated by arch_set_tls.
+ */
+
+ /* Store the i387 legacy FP registers which the host will use */
+ if (um_i387_from_fxsr(fpstate_stub, (void *)&regs->fp))
+ return -EINVAL;
+#else
+ /*
+ * On x86_64, we need to sync the FS_BASE/GS_BASE registers using the
+ * arch specific data.
+ */
+ if (data->arch_data.fs_base != regs->gp[FS_BASE / sizeof(unsigned long)]) {
+ data->arch_data.fs_base = regs->gp[FS_BASE / sizeof(unsigned long)];
+ data->arch_data.sync |= STUB_SYNC_FS_BASE;
+ }
+ if (data->arch_data.gs_base != regs->gp[GS_BASE / sizeof(unsigned long)]) {
+ data->arch_data.gs_base = regs->gp[GS_BASE / sizeof(unsigned long)];
+ data->arch_data.sync |= STUB_SYNC_GS_BASE;
+ }
+#endif
+
+ return 0;
+}
diff --git a/arch/x86/um/ptrace.c b/arch/x86/um/ptrace.c
index 57c504fd5626..3275870330fe 100644
--- a/arch/x86/um/ptrace.c
+++ b/arch/x86/um/ptrace.c
@@ -25,7 +25,8 @@ static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
return tmp;
}
-static inline unsigned long twd_fxsr_to_i387(struct user_fxsr_struct *fxsave)
+static inline unsigned long
+twd_fxsr_to_i387(const struct user_fxsr_struct *fxsave)
{
struct _fpxreg *st = NULL;
unsigned long twd = (unsigned long) fxsave->twd;
@@ -69,12 +70,16 @@ static inline unsigned long twd_fxsr_to_i387(struct user_fxsr_struct *fxsave)
return ret;
}
-/* Get/set the old 32bit i387 registers (pre-FPX) */
-static int fpregs_legacy_get(struct task_struct *target,
- const struct user_regset *regset,
- struct membuf to)
+/*
+ * Get/set the old 32bit i387 registers (pre-FPX)
+ *
+ * We provide simple wrappers for mcontext.c, they are only defined locally
+ * because mcontext.c is userspace facing and needs to a different definition
+ * of the structures.
+ */
+static int _um_i387_from_fxsr(struct membuf to,
+ const struct user_fxsr_struct *fxsave)
{
- struct user_fxsr_struct *fxsave = (void *)target->thread.regs.regs.fp;
int i;
membuf_store(&to, (unsigned long)fxsave->cwd | 0xffff0000ul);
@@ -91,23 +96,36 @@ static int fpregs_legacy_get(struct task_struct *target,
return 0;
}
-static int fpregs_legacy_set(struct task_struct *target,
+int um_i387_from_fxsr(struct user_i387_struct *i387,
+ const struct user_fxsr_struct *fxsave);
+
+int um_i387_from_fxsr(struct user_i387_struct *i387,
+ const struct user_fxsr_struct *fxsave)
+{
+ struct membuf to = {
+ .p = i387,
+ .left = sizeof(*i387),
+ };
+
+ return _um_i387_from_fxsr(to, fxsave);
+}
+
+static int fpregs_legacy_get(struct task_struct *target,
const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- const void *kbuf, const void __user *ubuf)
+ struct membuf to)
{
struct user_fxsr_struct *fxsave = (void *)target->thread.regs.regs.fp;
- const struct user_i387_struct *from;
- struct user_i387_struct buf;
- int i;
- if (ubuf) {
- if (copy_from_user(&buf, ubuf, sizeof(buf)))
- return -EFAULT;
- from = &buf;
- } else {
- from = kbuf;
- }
+ return _um_i387_from_fxsr(to, fxsave);
+}
+
+int um_fxsr_from_i387(struct user_fxsr_struct *fxsave,
+ const struct user_i387_struct *from);
+
+int um_fxsr_from_i387(struct user_fxsr_struct *fxsave,
+ const struct user_i387_struct *from)
+{
+ int i;
fxsave->cwd = (unsigned short)(from->cwd & 0xffff);
fxsave->swd = (unsigned short)(from->swd & 0xffff);
@@ -125,6 +143,26 @@ static int fpregs_legacy_set(struct task_struct *target,
return 0;
}
+
+static int fpregs_legacy_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ struct user_fxsr_struct *fxsave = (void *)target->thread.regs.regs.fp;
+ const struct user_i387_struct *from;
+ struct user_i387_struct buf;
+
+ if (ubuf) {
+ if (copy_from_user(&buf, ubuf, sizeof(buf)))
+ return -EFAULT;
+ from = &buf;
+ } else {
+ from = kbuf;
+ }
+
+ return um_fxsr_from_i387(fxsave, &buf);
+}
#endif
static int genregs_get(struct task_struct *target,
diff --git a/arch/x86/um/shared/sysdep/kernel-offsets.h b/arch/x86/um/shared/sysdep/kernel-offsets.h
index 48de3a71f845..6fd1ed400399 100644
--- a/arch/x86/um/shared/sysdep/kernel-offsets.h
+++ b/arch/x86/um/shared/sysdep/kernel-offsets.h
@@ -4,7 +4,9 @@
#include <linux/elf.h>
#include <linux/crypto.h>
#include <linux/kbuild.h>
+#include <linux/audit.h>
#include <asm/mman.h>
+#include <asm/seccomp.h>
/* workaround for a warning with -Wmissing-prototypes */
void foo(void);
diff --git a/arch/x86/um/shared/sysdep/mcontext.h b/arch/x86/um/shared/sysdep/mcontext.h
index b724c54da316..6fe490cc5b98 100644
--- a/arch/x86/um/shared/sysdep/mcontext.h
+++ b/arch/x86/um/shared/sysdep/mcontext.h
@@ -6,7 +6,16 @@
#ifndef __SYS_SIGCONTEXT_X86_H
#define __SYS_SIGCONTEXT_X86_H
+#include <stub-data.h>
+
extern void get_regs_from_mc(struct uml_pt_regs *, mcontext_t *);
+extern void get_mc_from_regs(struct uml_pt_regs *regs, mcontext_t *mc,
+ int single_stepping);
+
+extern int get_stub_state(struct uml_pt_regs *regs, struct stub_data *data,
+ unsigned long *fp_size_out);
+extern int set_stub_state(struct uml_pt_regs *regs, struct stub_data *data,
+ int single_stepping);
#ifdef __i386__
diff --git a/arch/x86/um/shared/sysdep/stub-data.h b/arch/x86/um/shared/sysdep/stub-data.h
new file mode 100644
index 000000000000..82b1b7f8ac3d
--- /dev/null
+++ b/arch/x86/um/shared/sysdep/stub-data.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ARCH_STUB_DATA_H
+#define __ARCH_STUB_DATA_H
+
+#ifdef __i386__
+#include <generated/asm-offsets.h>
+#include <asm/ldt.h>
+
+struct stub_data_arch {
+ int sync;
+ struct user_desc tls[UM_KERN_GDT_ENTRY_TLS_ENTRIES];
+};
+#else
+#define STUB_SYNC_FS_BASE (1 << 0)
+#define STUB_SYNC_GS_BASE (1 << 1)
+struct stub_data_arch {
+ int sync;
+ unsigned long fs_base;
+ unsigned long gs_base;
+};
+#endif
+
+#endif /* __ARCH_STUB_DATA_H */
diff --git a/arch/x86/um/shared/sysdep/stub.h b/arch/x86/um/shared/sysdep/stub.h
index dc89f4423454..4fa58f5b4fca 100644
--- a/arch/x86/um/shared/sysdep/stub.h
+++ b/arch/x86/um/shared/sysdep/stub.h
@@ -13,3 +13,5 @@
extern void stub_segv_handler(int, siginfo_t *, void *);
extern void stub_syscall_handler(void);
+extern void stub_signal_interrupt(int, siginfo_t *, void *);
+extern void stub_signal_restorer(void);
diff --git a/arch/x86/um/shared/sysdep/stub_32.h b/arch/x86/um/shared/sysdep/stub_32.h
index 390988132c0a..df568fc3ceb4 100644
--- a/arch/x86/um/shared/sysdep/stub_32.h
+++ b/arch/x86/um/shared/sysdep/stub_32.h
@@ -131,4 +131,17 @@ static __always_inline void *get_stub_data(void)
"call *%%eax ;" \
:: "i" ((1 + STUB_DATA_PAGES) * UM_KERN_PAGE_SIZE), \
"i" (&fn))
+
+static __always_inline void
+stub_seccomp_restore_state(struct stub_data_arch *arch)
+{
+ for (int i = 0; i < sizeof(arch->tls) / sizeof(arch->tls[0]); i++) {
+ if (arch->sync & (1 << i))
+ stub_syscall1(__NR_set_thread_area,
+ (unsigned long) &arch->tls[i]);
+ }
+
+ arch->sync = 0;
+}
+
#endif
diff --git a/arch/x86/um/shared/sysdep/stub_64.h b/arch/x86/um/shared/sysdep/stub_64.h
index 294affbec742..9cfd31afa769 100644
--- a/arch/x86/um/shared/sysdep/stub_64.h
+++ b/arch/x86/um/shared/sysdep/stub_64.h
@@ -10,6 +10,7 @@
#include <sysdep/ptrace_user.h>
#include <generated/asm-offsets.h>
#include <linux/stddef.h>
+#include <asm/prctl.h>
#define STUB_MMAP_NR __NR_mmap
#define MMAP_OFFSET(o) (o)
@@ -134,4 +135,20 @@ static __always_inline void *get_stub_data(void)
"call *%%rax ;" \
:: "i" ((1 + STUB_DATA_PAGES) * UM_KERN_PAGE_SIZE), \
"i" (&fn))
+
+static __always_inline void
+stub_seccomp_restore_state(struct stub_data_arch *arch)
+{
+ /*
+ * We could use _writefsbase_u64/_writegsbase_u64 if the host reports
+ * support in the hwcaps (HWCAP2_FSGSBASE).
+ */
+ if (arch->sync & STUB_SYNC_FS_BASE)
+ stub_syscall2(__NR_arch_prctl, ARCH_SET_FS, arch->fs_base);
+ if (arch->sync & STUB_SYNC_GS_BASE)
+ stub_syscall2(__NR_arch_prctl, ARCH_SET_GS, arch->gs_base);
+
+ arch->sync = 0;
+}
+
#endif
diff --git a/arch/x86/um/tls_32.c b/arch/x86/um/tls_32.c
index fbb129023080..cb3f17627d16 100644
--- a/arch/x86/um/tls_32.c
+++ b/arch/x86/um/tls_32.c
@@ -12,6 +12,7 @@
#include <skas.h>
#include <sysdep/tls.h>
#include <asm/desc.h>
+#include <stub-data.h>
/*
* If needed we can detect when it's uninitialized.
@@ -21,14 +22,25 @@
static int host_supports_tls = -1;
int host_gdt_entry_tls_min;
-static int do_set_thread_area(struct user_desc *info)
+static int do_set_thread_area(struct task_struct* task, struct user_desc *info)
{
int ret;
- u32 cpu;
- cpu = get_cpu();
- ret = os_set_thread_area(info, userspace_pid[cpu]);
- put_cpu();
+ if (info->entry_number < host_gdt_entry_tls_min ||
+ info->entry_number >= host_gdt_entry_tls_min + GDT_ENTRY_TLS_ENTRIES)
+ return -EINVAL;
+
+ if (using_seccomp) {
+ int idx = info->entry_number - host_gdt_entry_tls_min;
+ struct stub_data *data = (void *)task->mm->context.id.stack;
+
+ data->arch_data.tls[idx] = *info;
+ data->arch_data.sync |= BIT(idx);
+
+ return 0;
+ }
+
+ ret = os_set_thread_area(info, task->mm->context.id.pid);
if (ret)
printk(KERN_ERR "PTRACE_SET_THREAD_AREA failed, err = %d, "
@@ -97,7 +109,7 @@ static int load_TLS(int flags, struct task_struct *to)
if (!(flags & O_FORCE) && curr->flushed)
continue;
- ret = do_set_thread_area(&curr->tls);
+ ret = do_set_thread_area(current, &curr->tls);
if (ret)
goto out;
@@ -275,7 +287,7 @@ SYSCALL_DEFINE1(set_thread_area, struct user_desc __user *, user_desc)
return -EFAULT;
}
- ret = do_set_thread_area(&info);
+ ret = do_set_thread_area(current, &info);
if (ret)
return ret;
return set_tls_entry(current, &info, idx, 1);
generated by cgit (git 2.34.1) at 2025-06-19 23:35:02 +0000