The patch titled
Subject: signal: refactor copy_siginfo_to_user32
has been added to the -mm tree. Its filename is
signal-refactor-copy_siginfo_to_user32.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/signal-refactor-copy_siginfo_to_user32.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/signal-refactor-copy_siginfo_to_user32.patch
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------------------------------------------------------
From: Christoph Hellwig <hch@xxxxxx>
Subject: signal: refactor copy_siginfo_to_user32
Factor out a copy_siginfo_to_external32 helper from copy_siginfo_to_user32
that fills out the compat_siginfo, but does so on a kernel space data
structure. With that we can let architectures override
copy_siginfo_to_user32 with their own implementations using
copy_siginfo_to_external32. That allows moving the x32 SIGCHLD purely to
x86 architecture code.
As a nice side effect copy_siginfo_to_external32 also comes in handy for
avoiding a set_fs() call in the coredump code later on.
Contains improvements from Eric W. Biederman and Arnd Bergmann.
Link: http://lkml.kernel.org/r/20200505101256.3121270-5-hch@xxxxxx
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: "Eric W . Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Jeremy Kerr <jk@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/ia32/ia32_signal.c | 2
arch/x86/include/asm/compat.h | 8 +-
arch/x86/kernel/signal.c | 28 ++++++++
include/linux/compat.h | 11 ++-
kernel/signal.c | 106 ++++++++++++++++----------------
5 files changed, 96 insertions(+), 59 deletions(-)
--- a/arch/x86/ia32/ia32_signal.c~signal-refactor-copy_siginfo_to_user32
+++ a/arch/x86/ia32/ia32_signal.c
@@ -350,7 +350,7 @@ int ia32_setup_rt_frame(int sig, struct
unsafe_put_user(*(__u64 *)set, (__u64 *)&frame->uc.uc_sigmask, Efault);
user_access_end();
- if (__copy_siginfo_to_user32(&frame->info, &ksig->info, false))
+ if (__copy_siginfo_to_user32(&frame->info, &ksig->info))
return -EFAULT;
/* Set up registers for signal handler */
--- a/arch/x86/include/asm/compat.h~signal-refactor-copy_siginfo_to_user32
+++ a/arch/x86/include/asm/compat.h
@@ -214,7 +214,11 @@ static inline bool in_compat_syscall(voi
#endif
struct compat_siginfo;
-int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
- const kernel_siginfo_t *from, bool x32_ABI);
+
+#ifdef CONFIG_X86_X32_ABI
+int copy_siginfo_to_user32(struct compat_siginfo __user *to,
+ const kernel_siginfo_t *from);
+#define copy_siginfo_to_user32 copy_siginfo_to_user32
+#endif /* CONFIG_X86_X32_ABI */
#endif /* _ASM_X86_COMPAT_H */
--- a/arch/x86/kernel/signal.c~signal-refactor-copy_siginfo_to_user32
+++ a/arch/x86/kernel/signal.c
@@ -37,6 +37,7 @@
#include <asm/vm86.h>
#ifdef CONFIG_X86_64
+#include <linux/compat.h>
#include <asm/proto.h>
#include <asm/ia32_unistd.h>
#endif /* CONFIG_X86_64 */
@@ -511,6 +512,31 @@ Efault:
}
#endif /* CONFIG_X86_32 */
+#ifdef CONFIG_X86_X32_ABI
+static int x32_copy_siginfo_to_user(struct compat_siginfo __user *to,
+ const struct kernel_siginfo *from)
+{
+ struct compat_siginfo new;
+
+ copy_siginfo_to_external32(&new, from);
+ if (from->si_signo == SIGCHLD) {
+ new._sifields._sigchld_x32._utime = from->si_utime;
+ new._sifields._sigchld_x32._stime = from->si_stime;
+ }
+ if (copy_to_user(to, &new, sizeof(struct compat_siginfo)))
+ return -EFAULT;
+ return 0;
+}
+
+int copy_siginfo_to_user32(struct compat_siginfo __user *to,
+ const struct kernel_siginfo *from)
+{
+ if (in_x32_syscall())
+ return x32_copy_siginfo_to_user(to, from);
+ return __copy_siginfo_to_user32(to, from);
+}
+#endif /* CONFIG_X86_X32_ABI */
+
static int x32_setup_rt_frame(struct ksignal *ksig,
compat_sigset_t *set,
struct pt_regs *regs)
@@ -543,7 +569,7 @@ static int x32_setup_rt_frame(struct ksi
user_access_end();
if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
- if (__copy_siginfo_to_user32(&frame->info, &ksig->info, true))
+ if (x32_copy_siginfo_to_user(&frame->info, &ksig->info))
return -EFAULT;
}
--- a/include/linux/compat.h~signal-refactor-copy_siginfo_to_user32
+++ a/include/linux/compat.h
@@ -402,8 +402,15 @@ long compat_get_bitmap(unsigned long *ma
unsigned long bitmap_size);
long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
unsigned long bitmap_size);
-int copy_siginfo_from_user32(kernel_siginfo_t *to, const struct compat_siginfo __user *from);
-int copy_siginfo_to_user32(struct compat_siginfo __user *to, const kernel_siginfo_t *from);
+void copy_siginfo_to_external32(struct compat_siginfo *to,
+ const struct kernel_siginfo *from);
+int copy_siginfo_from_user32(kernel_siginfo_t *to,
+ const struct compat_siginfo __user *from);
+int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
+ const kernel_siginfo_t *from);
+#ifndef copy_siginfo_to_user32
+#define copy_siginfo_to_user32 __copy_siginfo_to_user32
+#endif
int get_compat_sigevent(struct sigevent *event,
const struct compat_sigevent __user *u_event);
--- a/kernel/signal.c~signal-refactor-copy_siginfo_to_user32
+++ a/kernel/signal.c
@@ -3235,94 +3235,94 @@ int copy_siginfo_from_user(kernel_siginf
}
#ifdef CONFIG_COMPAT
-int copy_siginfo_to_user32(struct compat_siginfo __user *to,
- const struct kernel_siginfo *from)
-#if defined(CONFIG_X86_X32_ABI) || defined(CONFIG_IA32_EMULATION)
+/**
+ * copy_siginfo_to_external32 - copy a kernel siginfo into a compat user siginfo
+ * @to: compat siginfo destination
+ * @from: kernel siginfo source
+ *
+ * Note: This function does not work properly for the SIGCHLD on x32, but
+ * fortunately it doesn't have to. The only valid callers for this function are
+ * copy_siginfo_to_user32, which is overriden for x32 and the coredump code.
+ * The latter does not care because SIGCHLD will never cause a coredump.
+ */
+void copy_siginfo_to_external32(struct compat_siginfo *to,
+ const struct kernel_siginfo *from)
{
- return __copy_siginfo_to_user32(to, from, in_x32_syscall());
-}
-int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
- const struct kernel_siginfo *from, bool x32_ABI)
-#endif
-{
- struct compat_siginfo new;
- memset(&new, 0, sizeof(new));
+ memset(to, 0, sizeof(*to));
- new.si_signo = from->si_signo;
- new.si_errno = from->si_errno;
- new.si_code = from->si_code;
+ to->si_signo = from->si_signo;
+ to->si_errno = from->si_errno;
+ to->si_code = from->si_code;
switch(siginfo_layout(from->si_signo, from->si_code)) {
case SIL_KILL:
- new.si_pid = from->si_pid;
- new.si_uid = from->si_uid;
+ to->si_pid = from->si_pid;
+ to->si_uid = from->si_uid;
break;
case SIL_TIMER:
- new.si_tid = from->si_tid;
- new.si_overrun = from->si_overrun;
- new.si_int = from->si_int;
+ to->si_tid = from->si_tid;
+ to->si_overrun = from->si_overrun;
+ to->si_int = from->si_int;
break;
case SIL_POLL:
- new.si_band = from->si_band;
- new.si_fd = from->si_fd;
+ to->si_band = from->si_band;
+ to->si_fd = from->si_fd;
break;
case SIL_FAULT:
- new.si_addr = ptr_to_compat(from->si_addr);
+ to->si_addr = ptr_to_compat(from->si_addr);
#ifdef __ARCH_SI_TRAPNO
- new.si_trapno = from->si_trapno;
+ to->si_trapno = from->si_trapno;
#endif
break;
case SIL_FAULT_MCEERR:
- new.si_addr = ptr_to_compat(from->si_addr);
+ to->si_addr = ptr_to_compat(from->si_addr);
#ifdef __ARCH_SI_TRAPNO
- new.si_trapno = from->si_trapno;
+ to->si_trapno = from->si_trapno;
#endif
- new.si_addr_lsb = from->si_addr_lsb;
+ to->si_addr_lsb = from->si_addr_lsb;
break;
case SIL_FAULT_BNDERR:
- new.si_addr = ptr_to_compat(from->si_addr);
+ to->si_addr = ptr_to_compat(from->si_addr);
#ifdef __ARCH_SI_TRAPNO
- new.si_trapno = from->si_trapno;
+ to->si_trapno = from->si_trapno;
#endif
- new.si_lower = ptr_to_compat(from->si_lower);
- new.si_upper = ptr_to_compat(from->si_upper);
+ to->si_lower = ptr_to_compat(from->si_lower);
+ to->si_upper = ptr_to_compat(from->si_upper);
break;
case SIL_FAULT_PKUERR:
- new.si_addr = ptr_to_compat(from->si_addr);
+ to->si_addr = ptr_to_compat(from->si_addr);
#ifdef __ARCH_SI_TRAPNO
- new.si_trapno = from->si_trapno;
+ to->si_trapno = from->si_trapno;
#endif
- new.si_pkey = from->si_pkey;
+ to->si_pkey = from->si_pkey;
break;
case SIL_CHLD:
- new.si_pid = from->si_pid;
- new.si_uid = from->si_uid;
- new.si_status = from->si_status;
-#ifdef CONFIG_X86_X32_ABI
- if (x32_ABI) {
- new._sifields._sigchld_x32._utime = from->si_utime;
- new._sifields._sigchld_x32._stime = from->si_stime;
- } else
-#endif
- {
- new.si_utime = from->si_utime;
- new.si_stime = from->si_stime;
- }
+ to->si_pid = from->si_pid;
+ to->si_uid = from->si_uid;
+ to->si_status = from->si_status;
+ to->si_utime = from->si_utime;
+ to->si_stime = from->si_stime;
break;
case SIL_RT:
- new.si_pid = from->si_pid;
- new.si_uid = from->si_uid;
- new.si_int = from->si_int;
+ to->si_pid = from->si_pid;
+ to->si_uid = from->si_uid;
+ to->si_int = from->si_int;
break;
case SIL_SYS:
- new.si_call_addr = ptr_to_compat(from->si_call_addr);
- new.si_syscall = from->si_syscall;
- new.si_arch = from->si_arch;
+ to->si_call_addr = ptr_to_compat(from->si_call_addr);
+ to->si_syscall = from->si_syscall;
+ to->si_arch = from->si_arch;
break;
}
+}
+int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
+ const struct kernel_siginfo *from)
+{
+ struct compat_siginfo new;
+
+ copy_siginfo_to_external32(&new, from);
if (copy_to_user(to, &new, sizeof(struct compat_siginfo)))
return -EFAULT;
-
return 0;
}
_
Patches currently in -mm which might be from hch@xxxxxx are
x86-hyperv-use-vmalloc_exec-for-the-hypercall-page.patch
x86-fix-vmap-arguments-in-map_irq_stack.patch
staging-android-ion-use-vmap-instead-of-vm_map_ram.patch
staging-media-ipu3-use-vmap-instead-of-reimplementing-it.patch
dma-mapping-use-vmap-insted-of-reimplementing-it.patch
powerpc-add-an-ioremap_phb-helper.patch
powerpc-remove-__ioremap_at-and-__iounmap_at.patch
mm-remove-__get_vm_area.patch
mm-unexport-unmap_kernel_range_noflush.patch
mm-rename-config_pgtable_mapping-to-config_zsmalloc_pgtable_mapping.patch
mm-only-allow-page-table-mappings-for-built-in-zsmalloc.patch
mm-pass-addr-as-unsigned-long-to-vb_free.patch
mm-remove-vmap_page_range_noflush-and-vunmap_page_range.patch
mm-rename-vmap_page_range-to-map_kernel_range.patch
mm-dont-return-the-number-of-pages-from-map_kernel_range_noflush.patch
mm-remove-map_vm_range.patch
mm-remove-unmap_vmap_area.patch
mm-remove-the-prot-argument-from-vm_map_ram.patch
mm-enforce-that-vmap-cant-map-pages-executable.patch
gpu-drm-remove-the-powerpc-hack-in-drm_legacy_sg_alloc.patch
mm-remove-the-pgprot-argument-to-__vmalloc.patch
mm-remove-the-prot-argument-to-__vmalloc_node.patch
mm-remove-both-instances-of-__vmalloc_node_flags.patch
mm-remove-__vmalloc_node_flags_caller.patch
mm-switch-the-test_vmalloc-module-to-use-__vmalloc_node.patch
mm-remove-vmalloc_user_node_flags.patch
arm64-use-__vmalloc_node-in-arch_alloc_vmap_stack.patch
powerpc-use-__vmalloc_node-in-alloc_vm_stack.patch
s390-use-__vmalloc_node-in-stack_alloc.patch
powerpc-spufs-stop-using-access_ok.patch
powerpc-spufs-simplify-spufs-core-dumping.patch
signal-refactor-copy_siginfo_to_user32.patch
binfmt_elf-remove-the-set_fskernel_ds-in-elf_core_dump.patch
binfmt_elf_fdpic-remove-the-set_fskernel_ds-in-elf_fdpic_core_dump.patch
exec-simplify-the-copy_strings_kernel-calling-convention.patch
exec-open-code-copy_string_kernel.patch
amdgpu-a-null-mm-does-not-mean-a-thread-is-a-kthread.patch
kernel-move-use_mm-unuse_mm-to-kthreadc.patch
kernel-move-use_mm-unuse_mm-to-kthreadc-v2.patch
kernel-better-document-the-use_mm-unuse_mm-api-contract.patch
kernel-better-document-the-use_mm-unuse_mm-api-contract-v2.patch
kernel-set-user_ds-in-kthread_use_mm.patch
