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Message-ID: <166616974172.401.10111186283861148120.tip-bot2@tip-bot2>
Date: Wed, 19 Oct 2022 08:55:41 -0000
From: "tip-bot2 for Brian Gerst" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Brian Gerst <brgerst@...il.com>, Borislav Petkov <bp@...e.de>,
"Eric W. Biederman" <ebiederm@...ssion.com>, x86@...nel.org,
linux-kernel@...r.kernel.org
Subject: [tip: x86/misc] x86/signal/32: Merge native and compat 32-bit signal code
The following commit has been merged into the x86/misc branch of tip:
Commit-ID: 24e6dc35ccd825de7c71751610ff8f3295347e5b
Gitweb: https://git.kernel.org/tip/24e6dc35ccd825de7c71751610ff8f3295347e5b
Author: Brian Gerst <brgerst@...il.com>
AuthorDate: Mon, 06 Jun 2022 16:38:01 -04:00
Committer: Borislav Petkov <bp@...e.de>
CommitterDate: Wed, 19 Oct 2022 09:58:49 +02:00
x86/signal/32: Merge native and compat 32-bit signal code
There are significant differences between signal handling on 32-bit vs.
64-bit, like different structure layouts and legacy syscalls. Instead
of duplicating that code for native and compat, merge both versions
into one file.
Signed-off-by: Brian Gerst <brgerst@...il.com>
Signed-off-by: Borislav Petkov <bp@...e.de>
Acked-by: "Eric W. Biederman" <ebiederm@...ssion.com>
Link: https://lore.kernel.org/r/20220606203802.158958-8-brgerst@gmail.com
Signed-off-by: Borislav Petkov <bp@...e.de>
---
arch/x86/ia32/Makefile | 2 +-
arch/x86/ia32/ia32_signal.c | 340 +-----------------------------
arch/x86/include/asm/segment.h | 1 +-
arch/x86/kernel/Makefile | 4 +-
arch/x86/kernel/signal.c | 219 +------------------
arch/x86/kernel/signal_32.c | 379 ++++++++++++++++++++++++++++++++-
include/linux/syscalls.h | 2 +-
7 files changed, 390 insertions(+), 557 deletions(-)
delete mode 100644 arch/x86/ia32/ia32_signal.c
create mode 100644 arch/x86/kernel/signal_32.c
diff --git a/arch/x86/ia32/Makefile b/arch/x86/ia32/Makefile
index e481056..333556a 100644
--- a/arch/x86/ia32/Makefile
+++ b/arch/x86/ia32/Makefile
@@ -3,7 +3,5 @@
# Makefile for the ia32 kernel emulation subsystem.
#
-obj-$(CONFIG_IA32_EMULATION) := ia32_signal.o
-
audit-class-$(CONFIG_AUDIT) := audit.o
obj-$(CONFIG_IA32_EMULATION) += $(audit-class-y)
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
deleted file mode 100644
index e28421f..0000000
--- a/arch/x86/ia32/ia32_signal.c
+++ /dev/null
@@ -1,340 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * linux/arch/x86_64/ia32/ia32_signal.c
- *
- * Copyright (C) 1991, 1992 Linus Torvalds
- *
- * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
- * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
- * 2000-12-* x86-64 compatibility mode signal handling by Andi Kleen
- */
-
-#include <linux/sched.h>
-#include <linux/sched/task_stack.h>
-#include <linux/mm.h>
-#include <linux/smp.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/wait.h>
-#include <linux/unistd.h>
-#include <linux/stddef.h>
-#include <linux/personality.h>
-#include <linux/compat.h>
-#include <linux/binfmts.h>
-#include <linux/syscalls.h>
-#include <asm/ucontext.h>
-#include <linux/uaccess.h>
-#include <asm/fpu/signal.h>
-#include <asm/ptrace.h>
-#include <asm/ia32_unistd.h>
-#include <asm/user32.h>
-#include <uapi/asm/sigcontext.h>
-#include <asm/proto.h>
-#include <asm/vdso.h>
-#include <asm/sigframe.h>
-#include <asm/sighandling.h>
-#include <asm/smap.h>
-
-static inline void reload_segments(struct sigcontext_32 *sc)
-{
- unsigned int cur;
-
- savesegment(gs, cur);
- if ((sc->gs | 0x03) != cur)
- load_gs_index(sc->gs | 0x03);
- savesegment(fs, cur);
- if ((sc->fs | 0x03) != cur)
- loadsegment(fs, sc->fs | 0x03);
- savesegment(ds, cur);
- if ((sc->ds | 0x03) != cur)
- loadsegment(ds, sc->ds | 0x03);
- savesegment(es, cur);
- if ((sc->es | 0x03) != cur)
- loadsegment(es, sc->es | 0x03);
-}
-
-/*
- * Do a signal return; undo the signal stack.
- */
-static bool ia32_restore_sigcontext(struct pt_regs *regs,
- struct sigcontext_32 __user *usc)
-{
- struct sigcontext_32 sc;
-
- /* Always make any pending restarted system calls return -EINTR */
- current->restart_block.fn = do_no_restart_syscall;
-
- if (unlikely(copy_from_user(&sc, usc, sizeof(sc))))
- return false;
-
- /* Get only the ia32 registers. */
- regs->bx = sc.bx;
- regs->cx = sc.cx;
- regs->dx = sc.dx;
- regs->si = sc.si;
- regs->di = sc.di;
- regs->bp = sc.bp;
- regs->ax = sc.ax;
- regs->sp = sc.sp;
- regs->ip = sc.ip;
-
- /* Get CS/SS and force CPL3 */
- regs->cs = sc.cs | 0x03;
- regs->ss = sc.ss | 0x03;
-
- regs->flags = (regs->flags & ~FIX_EFLAGS) | (sc.flags & FIX_EFLAGS);
- /* disable syscall checks */
- regs->orig_ax = -1;
-
- /*
- * Reload fs and gs if they have changed in the signal
- * handler. This does not handle long fs/gs base changes in
- * the handler, but does not clobber them at least in the
- * normal case.
- */
- reload_segments(&sc);
- return fpu__restore_sig(compat_ptr(sc.fpstate), 1);
-}
-
-COMPAT_SYSCALL_DEFINE0(sigreturn)
-{
- struct pt_regs *regs = current_pt_regs();
- struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
- sigset_t set;
-
- if (!access_ok(frame, sizeof(*frame)))
- goto badframe;
- if (__get_user(set.sig[0], &frame->sc.oldmask)
- || __get_user(((__u32 *)&set)[1], &frame->extramask[0]))
- goto badframe;
-
- set_current_blocked(&set);
-
- if (!ia32_restore_sigcontext(regs, &frame->sc))
- goto badframe;
- return regs->ax;
-
-badframe:
- signal_fault(regs, frame, "32bit sigreturn");
- return 0;
-}
-
-COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
-{
- struct pt_regs *regs = current_pt_regs();
- struct rt_sigframe_ia32 __user *frame;
- sigset_t set;
-
- frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);
-
- if (!access_ok(frame, sizeof(*frame)))
- goto badframe;
- if (__get_user(set.sig[0], (__u64 __user *)&frame->uc.uc_sigmask))
- goto badframe;
-
- set_current_blocked(&set);
-
- if (!ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext))
- goto badframe;
-
- if (compat_restore_altstack(&frame->uc.uc_stack))
- goto badframe;
-
- return regs->ax;
-
-badframe:
- signal_fault(regs, frame, "32bit rt sigreturn");
- return 0;
-}
-
-/*
- * Set up a signal frame.
- */
-
-#define get_user_seg(seg) ({ unsigned int v; savesegment(seg, v); v; })
-
-static __always_inline int
-__unsafe_setup_sigcontext32(struct sigcontext_32 __user *sc,
- void __user *fpstate,
- struct pt_regs *regs, unsigned int mask)
-{
- unsafe_put_user(get_user_seg(gs), (unsigned int __user *)&sc->gs, Efault);
- unsafe_put_user(get_user_seg(fs), (unsigned int __user *)&sc->fs, Efault);
- unsafe_put_user(get_user_seg(ds), (unsigned int __user *)&sc->ds, Efault);
- unsafe_put_user(get_user_seg(es), (unsigned int __user *)&sc->es, Efault);
-
- unsafe_put_user(regs->di, &sc->di, Efault);
- unsafe_put_user(regs->si, &sc->si, Efault);
- unsafe_put_user(regs->bp, &sc->bp, Efault);
- unsafe_put_user(regs->sp, &sc->sp, Efault);
- unsafe_put_user(regs->bx, &sc->bx, Efault);
- unsafe_put_user(regs->dx, &sc->dx, Efault);
- unsafe_put_user(regs->cx, &sc->cx, Efault);
- unsafe_put_user(regs->ax, &sc->ax, Efault);
- unsafe_put_user(current->thread.trap_nr, &sc->trapno, Efault);
- unsafe_put_user(current->thread.error_code, &sc->err, Efault);
- unsafe_put_user(regs->ip, &sc->ip, Efault);
- unsafe_put_user(regs->cs, (unsigned int __user *)&sc->cs, Efault);
- unsafe_put_user(regs->flags, &sc->flags, Efault);
- unsafe_put_user(regs->sp, &sc->sp_at_signal, Efault);
- unsafe_put_user(regs->ss, (unsigned int __user *)&sc->ss, Efault);
-
- unsafe_put_user(ptr_to_compat(fpstate), &sc->fpstate, Efault);
-
- /* non-iBCS2 extensions.. */
- unsafe_put_user(mask, &sc->oldmask, Efault);
- unsafe_put_user(current->thread.cr2, &sc->cr2, Efault);
- return 0;
-
-Efault:
- return -EFAULT;
-}
-
-#define unsafe_put_sigcontext32(sc, fp, regs, set, label) \
-do { \
- if (__unsafe_setup_sigcontext32(sc, fp, regs, set->sig[0])) \
- goto label; \
-} while(0)
-
-int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
- compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
- struct sigframe_ia32 __user *frame;
- void __user *restorer;
- void __user *fp = NULL;
-
- /* copy_to_user optimizes that into a single 8 byte store */
- static const struct {
- u16 poplmovl;
- u32 val;
- u16 int80;
- } __attribute__((packed)) code = {
- 0xb858, /* popl %eax ; movl $...,%eax */
- __NR_ia32_sigreturn,
- 0x80cd, /* int $0x80 */
- };
-
- frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
-
- if (ksig->ka.sa.sa_flags & SA_RESTORER) {
- restorer = ksig->ka.sa.sa_restorer;
- } else {
- /* Return stub is in 32bit vsyscall page */
- if (current->mm->context.vdso)
- restorer = current->mm->context.vdso +
- vdso_image_32.sym___kernel_sigreturn;
- else
- restorer = &frame->retcode;
- }
-
- if (!user_access_begin(frame, sizeof(*frame)))
- return -EFAULT;
-
- unsafe_put_user(ksig->sig, &frame->sig, Efault);
- unsafe_put_sigcontext32(&frame->sc, fp, regs, set, Efault);
- unsafe_put_user(set->sig[1], &frame->extramask[0], Efault);
- unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);
- /*
- * These are actually not used anymore, but left because some
- * gdb versions depend on them as a marker.
- */
- unsafe_put_user(*((u64 *)&code), (u64 __user *)frame->retcode, Efault);
- user_access_end();
-
- /* Set up registers for signal handler */
- regs->sp = (unsigned long) frame;
- regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
-
- /* Make -mregparm=3 work */
- regs->ax = ksig->sig;
- regs->dx = 0;
- regs->cx = 0;
-
- loadsegment(ds, __USER_DS);
- loadsegment(es, __USER_DS);
-
- regs->cs = __USER32_CS;
- regs->ss = __USER_DS;
-
- return 0;
-Efault:
- user_access_end();
- return -EFAULT;
-}
-
-int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
- compat_sigset_t *set = (compat_sigset_t *) sigmask_to_save();
- struct rt_sigframe_ia32 __user *frame;
- void __user *restorer;
- void __user *fp = NULL;
-
- /* unsafe_put_user optimizes that into a single 8 byte store */
- static const struct {
- u8 movl;
- u32 val;
- u16 int80;
- u8 pad;
- } __attribute__((packed)) code = {
- 0xb8,
- __NR_ia32_rt_sigreturn,
- 0x80cd,
- 0,
- };
-
- frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
-
- if (!user_access_begin(frame, sizeof(*frame)))
- return -EFAULT;
-
- unsafe_put_user(ksig->sig, &frame->sig, Efault);
- unsafe_put_user(ptr_to_compat(&frame->info), &frame->pinfo, Efault);
- unsafe_put_user(ptr_to_compat(&frame->uc), &frame->puc, Efault);
-
- /* Create the ucontext. */
- if (static_cpu_has(X86_FEATURE_XSAVE))
- unsafe_put_user(UC_FP_XSTATE, &frame->uc.uc_flags, Efault);
- else
- unsafe_put_user(0, &frame->uc.uc_flags, Efault);
- unsafe_put_user(0, &frame->uc.uc_link, Efault);
- unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
-
- if (ksig->ka.sa.sa_flags & SA_RESTORER)
- restorer = ksig->ka.sa.sa_restorer;
- else
- restorer = current->mm->context.vdso +
- vdso_image_32.sym___kernel_rt_sigreturn;
- unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);
-
- /*
- * Not actually used anymore, but left because some gdb
- * versions need it.
- */
- unsafe_put_user(*((u64 *)&code), (u64 __user *)frame->retcode, Efault);
- unsafe_put_sigcontext32(&frame->uc.uc_mcontext, fp, regs, set, Efault);
- unsafe_put_user(*(__u64 *)set, (__u64 __user *)&frame->uc.uc_sigmask, Efault);
- user_access_end();
-
- if (__copy_siginfo_to_user32(&frame->info, &ksig->info))
- return -EFAULT;
-
- /* Set up registers for signal handler */
- regs->sp = (unsigned long) frame;
- regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
-
- /* Make -mregparm=3 work */
- regs->ax = ksig->sig;
- regs->dx = (unsigned long) &frame->info;
- regs->cx = (unsigned long) &frame->uc;
-
- loadsegment(ds, __USER_DS);
- loadsegment(es, __USER_DS);
-
- regs->cs = __USER32_CS;
- regs->ss = __USER_DS;
-
- return 0;
-Efault:
- user_access_end();
- return -EFAULT;
-}
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index e056c29..c390a67 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -135,6 +135,7 @@
#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS*8)
#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8 + 3)
#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8 + 3)
+#define __USER32_CS __USER_CS
#define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS*8)
/* segment for calling fn: */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index f901658..72e1371 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -53,8 +53,8 @@ obj-y += setup.o x86_init.o i8259.o irqinit.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
obj-$(CONFIG_IRQ_WORK) += irq_work.o
obj-y += probe_roms.o
-obj-$(CONFIG_X86_32) += sys_ia32.o
-obj-$(CONFIG_IA32_EMULATION) += sys_ia32.o
+obj-$(CONFIG_X86_32) += sys_ia32.o signal_32.o
+obj-$(CONFIG_IA32_EMULATION) += sys_ia32.o signal_32.o
obj-$(CONFIG_X86_64) += sys_x86_64.o
obj-$(CONFIG_X86_ESPFIX64) += espfix_64.o
obj-$(CONFIG_SYSFS) += ksysfs.o
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 0511e05..962cfd8 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -92,10 +92,6 @@ static void force_valid_ss(struct pt_regs *regs)
ar != (AR_DPL3 | AR_S | AR_P | AR_TYPE_RWDATA_EXPDOWN))
regs->ss = __USER_DS;
}
-# define CONTEXT_COPY_SIZE offsetof(struct sigcontext, reserved1)
-#else
-# define CONTEXT_COPY_SIZE sizeof(struct sigcontext)
-#endif
static bool restore_sigcontext(struct pt_regs *regs,
struct sigcontext __user *usc,
@@ -106,16 +102,9 @@ static bool restore_sigcontext(struct pt_regs *regs,
/* Always make any pending restarted system calls return -EINTR */
current->restart_block.fn = do_no_restart_syscall;
- if (copy_from_user(&sc, usc, CONTEXT_COPY_SIZE))
+ if (copy_from_user(&sc, usc, offsetof(struct sigcontext, reserved1)))
return false;
-#ifdef CONFIG_X86_32
- loadsegment(gs, sc.gs);
- regs->fs = sc.fs;
- regs->es = sc.es;
- regs->ds = sc.ds;
-#endif /* CONFIG_X86_32 */
-
regs->bx = sc.bx;
regs->cx = sc.cx;
regs->dx = sc.dx;
@@ -125,8 +114,6 @@ static bool restore_sigcontext(struct pt_regs *regs,
regs->ax = sc.ax;
regs->sp = sc.sp;
regs->ip = sc.ip;
-
-#ifdef CONFIG_X86_64
regs->r8 = sc.r8;
regs->r9 = sc.r9;
regs->r10 = sc.r10;
@@ -135,7 +122,6 @@ static bool restore_sigcontext(struct pt_regs *regs,
regs->r13 = sc.r13;
regs->r14 = sc.r14;
regs->r15 = sc.r15;
-#endif /* CONFIG_X86_64 */
/* Get CS/SS and force CPL3 */
regs->cs = sc.cs | 0x03;
@@ -145,33 +131,20 @@ static bool restore_sigcontext(struct pt_regs *regs,
/* disable syscall checks */
regs->orig_ax = -1;
-#ifdef CONFIG_X86_64
/*
* Fix up SS if needed for the benefit of old DOSEMU and
* CRIU.
*/
if (unlikely(!(uc_flags & UC_STRICT_RESTORE_SS) && user_64bit_mode(regs)))
force_valid_ss(regs);
-#endif
- return fpu__restore_sig((void __user *)sc.fpstate,
- IS_ENABLED(CONFIG_X86_32));
+ return fpu__restore_sig((void __user *)sc.fpstate, 0);
}
static __always_inline int
__unsafe_setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
struct pt_regs *regs, unsigned long mask)
{
-#ifdef CONFIG_X86_32
- unsigned int gs;
- savesegment(gs, gs);
-
- unsafe_put_user(gs, (unsigned int __user *)&sc->gs, Efault);
- unsafe_put_user(regs->fs, (unsigned int __user *)&sc->fs, Efault);
- unsafe_put_user(regs->es, (unsigned int __user *)&sc->es, Efault);
- unsafe_put_user(regs->ds, (unsigned int __user *)&sc->ds, Efault);
-#endif /* CONFIG_X86_32 */
-
unsafe_put_user(regs->di, &sc->di, Efault);
unsafe_put_user(regs->si, &sc->si, Efault);
unsafe_put_user(regs->bp, &sc->bp, Efault);
@@ -180,7 +153,6 @@ __unsafe_setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
unsafe_put_user(regs->dx, &sc->dx, Efault);
unsafe_put_user(regs->cx, &sc->cx, Efault);
unsafe_put_user(regs->ax, &sc->ax, Efault);
-#ifdef CONFIG_X86_64
unsafe_put_user(regs->r8, &sc->r8, Efault);
unsafe_put_user(regs->r9, &sc->r9, Efault);
unsafe_put_user(regs->r10, &sc->r10, Efault);
@@ -189,23 +161,15 @@ __unsafe_setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
unsafe_put_user(regs->r13, &sc->r13, Efault);
unsafe_put_user(regs->r14, &sc->r14, Efault);
unsafe_put_user(regs->r15, &sc->r15, Efault);
-#endif /* CONFIG_X86_64 */
unsafe_put_user(current->thread.trap_nr, &sc->trapno, Efault);
unsafe_put_user(current->thread.error_code, &sc->err, Efault);
unsafe_put_user(regs->ip, &sc->ip, Efault);
-#ifdef CONFIG_X86_32
- unsafe_put_user(regs->cs, (unsigned int __user *)&sc->cs, Efault);
- unsafe_put_user(regs->flags, &sc->flags, Efault);
- unsafe_put_user(regs->sp, &sc->sp_at_signal, Efault);
- unsafe_put_user(regs->ss, (unsigned int __user *)&sc->ss, Efault);
-#else /* !CONFIG_X86_32 */
unsafe_put_user(regs->flags, &sc->flags, Efault);
unsafe_put_user(regs->cs, &sc->cs, Efault);
unsafe_put_user(0, &sc->gs, Efault);
unsafe_put_user(0, &sc->fs, Efault);
unsafe_put_user(regs->ss, &sc->ss, Efault);
-#endif /* CONFIG_X86_32 */
unsafe_put_user(fpstate, (unsigned long __user *)&sc->fpstate, Efault);
@@ -228,6 +192,8 @@ do { \
(__u64 __user *)&(frame)->uc.uc_sigmask, \
label)
+#endif /* CONFIG_X86_64 */
+
/*
* Set up a signal frame.
*/
@@ -313,148 +279,7 @@ get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size,
return (void __user *)sp;
}
-#ifdef CONFIG_X86_32
-static const struct {
- u16 poplmovl;
- u32 val;
- u16 int80;
-} __attribute__((packed)) retcode = {
- 0xb858, /* popl %eax; movl $..., %eax */
- __NR_sigreturn,
- 0x80cd, /* int $0x80 */
-};
-
-static const struct {
- u8 movl;
- u32 val;
- u16 int80;
- u8 pad;
-} __attribute__((packed)) rt_retcode = {
- 0xb8, /* movl $..., %eax */
- __NR_rt_sigreturn,
- 0x80cd, /* int $0x80 */
- 0
-};
-
-int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
- sigset_t *set = sigmask_to_save();
- struct sigframe __user *frame;
- void __user *restorer;
- void __user *fp = NULL;
-
- frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
-
- if (!user_access_begin(frame, sizeof(*frame)))
- return -EFAULT;
-
- unsafe_put_user(ksig->sig, &frame->sig, Efault);
- unsafe_put_sigcontext(&frame->sc, fp, regs, set, Efault);
- unsafe_put_user(set->sig[1], &frame->extramask[0], Efault);
- if (current->mm->context.vdso)
- restorer = current->mm->context.vdso +
- vdso_image_32.sym___kernel_sigreturn;
- else
- restorer = &frame->retcode;
- if (ksig->ka.sa.sa_flags & SA_RESTORER)
- restorer = ksig->ka.sa.sa_restorer;
-
- /* Set up to return from userspace. */
- unsafe_put_user(restorer, &frame->pretcode, Efault);
-
- /*
- * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
- *
- * WE DO NOT USE IT ANY MORE! It's only left here for historical
- * reasons and because gdb uses it as a signature to notice
- * signal handler stack frames.
- */
- unsafe_put_user(*((u64 *)&retcode), (u64 *)frame->retcode, Efault);
- user_access_end();
-
- /* Set up registers for signal handler */
- regs->sp = (unsigned long)frame;
- regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
- regs->ax = (unsigned long)ksig->sig;
- regs->dx = 0;
- regs->cx = 0;
-
- regs->ds = __USER_DS;
- regs->es = __USER_DS;
- regs->ss = __USER_DS;
- regs->cs = __USER_CS;
-
- return 0;
-
-Efault:
- user_access_end();
- return -EFAULT;
-}
-
-int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
-{
- sigset_t *set = sigmask_to_save();
- struct rt_sigframe __user *frame;
- void __user *restorer;
- void __user *fp = NULL;
-
- frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
-
- if (!user_access_begin(frame, sizeof(*frame)))
- return -EFAULT;
-
- unsafe_put_user(ksig->sig, &frame->sig, Efault);
- unsafe_put_user(&frame->info, &frame->pinfo, Efault);
- unsafe_put_user(&frame->uc, &frame->puc, Efault);
-
- /* Create the ucontext. */
- if (static_cpu_has(X86_FEATURE_XSAVE))
- unsafe_put_user(UC_FP_XSTATE, &frame->uc.uc_flags, Efault);
- else
- unsafe_put_user(0, &frame->uc.uc_flags, Efault);
- unsafe_put_user(0, &frame->uc.uc_link, Efault);
- unsafe_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
-
- /* Set up to return from userspace. */
- restorer = current->mm->context.vdso +
- vdso_image_32.sym___kernel_rt_sigreturn;
- if (ksig->ka.sa.sa_flags & SA_RESTORER)
- restorer = ksig->ka.sa.sa_restorer;
- unsafe_put_user(restorer, &frame->pretcode, Efault);
-
- /*
- * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
- *
- * WE DO NOT USE IT ANY MORE! It's only left here for historical
- * reasons and because gdb uses it as a signature to notice
- * signal handler stack frames.
- */
- unsafe_put_user(*((u64 *)&rt_retcode), (u64 *)frame->retcode, Efault);
- unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault);
- unsafe_put_sigmask(set, frame, Efault);
- user_access_end();
-
- if (copy_siginfo_to_user(&frame->info, &ksig->info))
- return -EFAULT;
-
- /* Set up registers for signal handler */
- regs->sp = (unsigned long)frame;
- regs->ip = (unsigned long)ksig->ka.sa.sa_handler;
- regs->ax = (unsigned long)ksig->sig;
- regs->dx = (unsigned long)&frame->info;
- regs->cx = (unsigned long)&frame->uc;
-
- regs->ds = __USER_DS;
- regs->es = __USER_DS;
- regs->ss = __USER_DS;
- regs->cs = __USER_CS;
-
- return 0;
-Efault:
- user_access_end();
- return -EFAULT;
-}
-#else /* !CONFIG_X86_32 */
+#ifdef CONFIG_X86_64
static unsigned long frame_uc_flags(struct pt_regs *regs)
{
unsigned long flags;
@@ -545,7 +370,6 @@ Efault:
user_access_end();
return -EFAULT;
}
-#endif /* CONFIG_X86_32 */
#ifdef CONFIG_X86_X32_ABI
static int x32_copy_siginfo_to_user(struct compat_siginfo __user *to,
@@ -631,38 +455,6 @@ Efault:
/*
* Do a signal return; undo the signal stack.
*/
-#ifdef CONFIG_X86_32
-SYSCALL_DEFINE0(sigreturn)
-{
- struct pt_regs *regs = current_pt_regs();
- struct sigframe __user *frame;
- sigset_t set;
-
- frame = (struct sigframe __user *)(regs->sp - 8);
-
- if (!access_ok(frame, sizeof(*frame)))
- goto badframe;
- if (__get_user(set.sig[0], &frame->sc.oldmask) ||
- __get_user(set.sig[1], &frame->extramask[0]))
- goto badframe;
-
- set_current_blocked(&set);
-
- /*
- * x86_32 has no uc_flags bits relevant to restore_sigcontext.
- * Save a few cycles by skipping the __get_user.
- */
- if (!restore_sigcontext(regs, &frame->sc, 0))
- goto badframe;
- return regs->ax;
-
-badframe:
- signal_fault(regs, frame, "sigreturn");
-
- return 0;
-}
-#endif /* CONFIG_X86_32 */
-
SYSCALL_DEFINE0(rt_sigreturn)
{
struct pt_regs *regs = current_pt_regs();
@@ -692,6 +484,7 @@ badframe:
signal_fault(regs, frame, "rt_sigreturn");
return 0;
}
+#endif /* CONFIG_X86_64 */
/*
* There are four different struct types for signal frame: sigframe_ia32,
diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
new file mode 100644
index 0000000..2553136
--- /dev/null
+++ b/arch/x86/kernel/signal_32.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
+ * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
+ * 2000-12-* x86-64 compatibility mode signal handling by Andi Kleen
+ */
+
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/personality.h>
+#include <linux/compat.h>
+#include <linux/binfmts.h>
+#include <linux/syscalls.h>
+#include <asm/ucontext.h>
+#include <linux/uaccess.h>
+#include <asm/fpu/signal.h>
+#include <asm/ptrace.h>
+#include <asm/user32.h>
+#include <uapi/asm/sigcontext.h>
+#include <asm/proto.h>
+#include <asm/vdso.h>
+#include <asm/sigframe.h>
+#include <asm/sighandling.h>
+#include <asm/smap.h>
+
+#ifdef CONFIG_IA32_EMULATION
+#include <asm/ia32_unistd.h>
+
+static inline void reload_segments(struct sigcontext_32 *sc)
+{
+ unsigned int cur;
+
+ savesegment(gs, cur);
+ if ((sc->gs | 0x03) != cur)
+ load_gs_index(sc->gs | 0x03);
+ savesegment(fs, cur);
+ if ((sc->fs | 0x03) != cur)
+ loadsegment(fs, sc->fs | 0x03);
+ savesegment(ds, cur);
+ if ((sc->ds | 0x03) != cur)
+ loadsegment(ds, sc->ds | 0x03);
+ savesegment(es, cur);
+ if ((sc->es | 0x03) != cur)
+ loadsegment(es, sc->es | 0x03);
+}
+
+#define sigset32_t compat_sigset_t
+#define restore_altstack32 compat_restore_altstack
+#define unsafe_save_altstack32 unsafe_compat_save_altstack
+
+#else
+
+#define sigset32_t sigset_t
+#define __NR_ia32_sigreturn __NR_sigreturn
+#define __NR_ia32_rt_sigreturn __NR_rt_sigreturn
+#define restore_altstack32 restore_altstack
+#define unsafe_save_altstack32 unsafe_save_altstack
+#define __copy_siginfo_to_user32 copy_siginfo_to_user
+
+#endif
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+static bool ia32_restore_sigcontext(struct pt_regs *regs,
+ struct sigcontext_32 __user *usc)
+{
+ struct sigcontext_32 sc;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ if (unlikely(copy_from_user(&sc, usc, sizeof(sc))))
+ return false;
+
+ /* Get only the ia32 registers. */
+ regs->bx = sc.bx;
+ regs->cx = sc.cx;
+ regs->dx = sc.dx;
+ regs->si = sc.si;
+ regs->di = sc.di;
+ regs->bp = sc.bp;
+ regs->ax = sc.ax;
+ regs->sp = sc.sp;
+ regs->ip = sc.ip;
+
+ /* Get CS/SS and force CPL3 */
+ regs->cs = sc.cs | 0x03;
+ regs->ss = sc.ss | 0x03;
+
+ regs->flags = (regs->flags & ~FIX_EFLAGS) | (sc.flags & FIX_EFLAGS);
+ /* disable syscall checks */
+ regs->orig_ax = -1;
+
+#ifdef CONFIG_IA32_EMULATION
+ /*
+ * Reload fs and gs if they have changed in the signal
+ * handler. This does not handle long fs/gs base changes in
+ * the handler, but does not clobber them at least in the
+ * normal case.
+ */
+ reload_segments(&sc);
+#else
+ loadsegment(gs, sc.gs);
+ regs->fs = sc.fs;
+ regs->es = sc.es;
+ regs->ds = sc.ds;
+#endif
+
+ return fpu__restore_sig(compat_ptr(sc.fpstate), 1);
+}
+
+SYSCALL32_DEFINE0(sigreturn)
+{
+ struct pt_regs *regs = current_pt_regs();
+ struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
+ sigset_t set;
+
+ if (!access_ok(frame, sizeof(*frame)))
+ goto badframe;
+ if (__get_user(set.sig[0], &frame->sc.oldmask)
+ || __get_user(((__u32 *)&set)[1], &frame->extramask[0]))
+ goto badframe;
+
+ set_current_blocked(&set);
+
+ if (!ia32_restore_sigcontext(regs, &frame->sc))
+ goto badframe;
+ return regs->ax;
+
+badframe:
+ signal_fault(regs, frame, "32bit sigreturn");
+ return 0;
+}
+
+SYSCALL32_DEFINE0(rt_sigreturn)
+{
+ struct pt_regs *regs = current_pt_regs();
+ struct rt_sigframe_ia32 __user *frame;
+ sigset_t set;
+
+ frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);
+
+ if (!access_ok(frame, sizeof(*frame)))
+ goto badframe;
+ if (__get_user(*(__u64 *)&set, (__u64 __user *)&frame->uc.uc_sigmask))
+ goto badframe;
+
+ set_current_blocked(&set);
+
+ if (!ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext))
+ goto badframe;
+
+ if (restore_altstack32(&frame->uc.uc_stack))
+ goto badframe;
+
+ return regs->ax;
+
+badframe:
+ signal_fault(regs, frame, "32bit rt sigreturn");
+ return 0;
+}
+
+/*
+ * Set up a signal frame.
+ */
+
+#define get_user_seg(seg) ({ unsigned int v; savesegment(seg, v); v; })
+
+static __always_inline int
+__unsafe_setup_sigcontext32(struct sigcontext_32 __user *sc,
+ void __user *fpstate,
+ struct pt_regs *regs, unsigned int mask)
+{
+ unsafe_put_user(get_user_seg(gs), (unsigned int __user *)&sc->gs, Efault);
+#ifdef CONFIG_IA32_EMULATION
+ unsafe_put_user(get_user_seg(fs), (unsigned int __user *)&sc->fs, Efault);
+ unsafe_put_user(get_user_seg(ds), (unsigned int __user *)&sc->ds, Efault);
+ unsafe_put_user(get_user_seg(es), (unsigned int __user *)&sc->es, Efault);
+#else
+ unsafe_put_user(regs->fs, (unsigned int __user *)&sc->fs, Efault);
+ unsafe_put_user(regs->es, (unsigned int __user *)&sc->es, Efault);
+ unsafe_put_user(regs->ds, (unsigned int __user *)&sc->ds, Efault);
+#endif
+
+ unsafe_put_user(regs->di, &sc->di, Efault);
+ unsafe_put_user(regs->si, &sc->si, Efault);
+ unsafe_put_user(regs->bp, &sc->bp, Efault);
+ unsafe_put_user(regs->sp, &sc->sp, Efault);
+ unsafe_put_user(regs->bx, &sc->bx, Efault);
+ unsafe_put_user(regs->dx, &sc->dx, Efault);
+ unsafe_put_user(regs->cx, &sc->cx, Efault);
+ unsafe_put_user(regs->ax, &sc->ax, Efault);
+ unsafe_put_user(current->thread.trap_nr, &sc->trapno, Efault);
+ unsafe_put_user(current->thread.error_code, &sc->err, Efault);
+ unsafe_put_user(regs->ip, &sc->ip, Efault);
+ unsafe_put_user(regs->cs, (unsigned int __user *)&sc->cs, Efault);
+ unsafe_put_user(regs->flags, &sc->flags, Efault);
+ unsafe_put_user(regs->sp, &sc->sp_at_signal, Efault);
+ unsafe_put_user(regs->ss, (unsigned int __user *)&sc->ss, Efault);
+
+ unsafe_put_user(ptr_to_compat(fpstate), &sc->fpstate, Efault);
+
+ /* non-iBCS2 extensions.. */
+ unsafe_put_user(mask, &sc->oldmask, Efault);
+ unsafe_put_user(current->thread.cr2, &sc->cr2, Efault);
+ return 0;
+
+Efault:
+ return -EFAULT;
+}
+
+#define unsafe_put_sigcontext32(sc, fp, regs, set, label) \
+do { \
+ if (__unsafe_setup_sigcontext32(sc, fp, regs, set->sig[0])) \
+ goto label; \
+} while(0)
+
+int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
+{
+ sigset32_t *set = (sigset32_t *) sigmask_to_save();
+ struct sigframe_ia32 __user *frame;
+ void __user *restorer;
+ void __user *fp = NULL;
+
+ /* copy_to_user optimizes that into a single 8 byte store */
+ static const struct {
+ u16 poplmovl;
+ u32 val;
+ u16 int80;
+ } __attribute__((packed)) code = {
+ 0xb858, /* popl %eax ; movl $...,%eax */
+ __NR_ia32_sigreturn,
+ 0x80cd, /* int $0x80 */
+ };
+
+ frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
+
+ if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+ restorer = ksig->ka.sa.sa_restorer;
+ } else {
+ /* Return stub is in 32bit vsyscall page */
+ if (current->mm->context.vdso)
+ restorer = current->mm->context.vdso +
+ vdso_image_32.sym___kernel_sigreturn;
+ else
+ restorer = &frame->retcode;
+ }
+
+ if (!user_access_begin(frame, sizeof(*frame)))
+ return -EFAULT;
+
+ unsafe_put_user(ksig->sig, &frame->sig, Efault);
+ unsafe_put_sigcontext32(&frame->sc, fp, regs, set, Efault);
+ unsafe_put_user(set->sig[1], &frame->extramask[0], Efault);
+ unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);
+ /*
+ * These are actually not used anymore, but left because some
+ * gdb versions depend on them as a marker.
+ */
+ unsafe_put_user(*((u64 *)&code), (u64 __user *)frame->retcode, Efault);
+ user_access_end();
+
+ /* Set up registers for signal handler */
+ regs->sp = (unsigned long) frame;
+ regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
+
+ /* Make -mregparm=3 work */
+ regs->ax = ksig->sig;
+ regs->dx = 0;
+ regs->cx = 0;
+
+#ifdef CONFIG_IA32_EMULATION
+ loadsegment(ds, __USER_DS);
+ loadsegment(es, __USER_DS);
+#else
+ regs->ds = __USER_DS;
+ regs->es = __USER_DS;
+#endif
+
+ regs->cs = __USER32_CS;
+ regs->ss = __USER_DS;
+
+ return 0;
+Efault:
+ user_access_end();
+ return -EFAULT;
+}
+
+int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
+{
+ sigset32_t *set = (sigset32_t *) sigmask_to_save();
+ struct rt_sigframe_ia32 __user *frame;
+ void __user *restorer;
+ void __user *fp = NULL;
+
+ /* unsafe_put_user optimizes that into a single 8 byte store */
+ static const struct {
+ u8 movl;
+ u32 val;
+ u16 int80;
+ u8 pad;
+ } __attribute__((packed)) code = {
+ 0xb8,
+ __NR_ia32_rt_sigreturn,
+ 0x80cd,
+ 0,
+ };
+
+ frame = get_sigframe(ksig, regs, sizeof(*frame), &fp);
+
+ if (!user_access_begin(frame, sizeof(*frame)))
+ return -EFAULT;
+
+ unsafe_put_user(ksig->sig, &frame->sig, Efault);
+ unsafe_put_user(ptr_to_compat(&frame->info), &frame->pinfo, Efault);
+ unsafe_put_user(ptr_to_compat(&frame->uc), &frame->puc, Efault);
+
+ /* Create the ucontext. */
+ if (static_cpu_has(X86_FEATURE_XSAVE))
+ unsafe_put_user(UC_FP_XSTATE, &frame->uc.uc_flags, Efault);
+ else
+ unsafe_put_user(0, &frame->uc.uc_flags, Efault);
+ unsafe_put_user(0, &frame->uc.uc_link, Efault);
+ unsafe_save_altstack32(&frame->uc.uc_stack, regs->sp, Efault);
+
+ if (ksig->ka.sa.sa_flags & SA_RESTORER)
+ restorer = ksig->ka.sa.sa_restorer;
+ else
+ restorer = current->mm->context.vdso +
+ vdso_image_32.sym___kernel_rt_sigreturn;
+ unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);
+
+ /*
+ * Not actually used anymore, but left because some gdb
+ * versions need it.
+ */
+ unsafe_put_user(*((u64 *)&code), (u64 __user *)frame->retcode, Efault);
+ unsafe_put_sigcontext32(&frame->uc.uc_mcontext, fp, regs, set, Efault);
+ unsafe_put_user(*(__u64 *)set, (__u64 __user *)&frame->uc.uc_sigmask, Efault);
+ user_access_end();
+
+ if (__copy_siginfo_to_user32(&frame->info, &ksig->info))
+ return -EFAULT;
+
+ /* Set up registers for signal handler */
+ regs->sp = (unsigned long) frame;
+ regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
+
+ /* Make -mregparm=3 work */
+ regs->ax = ksig->sig;
+ regs->dx = (unsigned long) &frame->info;
+ regs->cx = (unsigned long) &frame->uc;
+
+#ifdef CONFIG_IA32_EMULATION
+ loadsegment(ds, __USER_DS);
+ loadsegment(es, __USER_DS);
+#else
+ regs->ds = __USER_DS;
+ regs->es = __USER_DS;
+#endif
+
+ regs->cs = __USER32_CS;
+ regs->ss = __USER_DS;
+
+ return 0;
+Efault:
+ user_access_end();
+ return -EFAULT;
+}
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index a34b0f9..33a0ee3 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -264,6 +264,7 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
#define SC_VAL64(type, name) ((type) name##_hi << 32 | name##_lo)
#ifdef CONFIG_COMPAT
+#define SYSCALL32_DEFINE0 COMPAT_SYSCALL_DEFINE0
#define SYSCALL32_DEFINE1 COMPAT_SYSCALL_DEFINE1
#define SYSCALL32_DEFINE2 COMPAT_SYSCALL_DEFINE2
#define SYSCALL32_DEFINE3 COMPAT_SYSCALL_DEFINE3
@@ -271,6 +272,7 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
#define SYSCALL32_DEFINE5 COMPAT_SYSCALL_DEFINE5
#define SYSCALL32_DEFINE6 COMPAT_SYSCALL_DEFINE6
#else
+#define SYSCALL32_DEFINE0 SYSCALL_DEFINE0
#define SYSCALL32_DEFINE1 SYSCALL_DEFINE1
#define SYSCALL32_DEFINE2 SYSCALL_DEFINE2
#define SYSCALL32_DEFINE3 SYSCALL_DEFINE3
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