From: Dmitry Safonov <dima@arista.com>
To: linux-kernel@vger.kernel.org
Cc: Dmitry Safonov <0x7f454c46@gmail.com>,
Dmitry Safonov <dima@arista.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Borislav Petkov <bp@alien8.de>,
Catalin Marinas <catalin.marinas@arm.com>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
Guo Ren <guoren@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
Ingo Molnar <mingo@redhat.com>, Oleg Nesterov <oleg@redhat.com>,
Russell King <linux@armlinux.org.uk>,
Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
Thomas Gleixner <tglx@linutronix.de>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Will Deacon <will@kernel.org>,
x86@kernel.org
Subject: [PATCH 15/19] x86/vdso: Migrate to user_landing
Date: Sun, 8 Nov 2020 05:17:25 +0000 [thread overview]
Message-ID: <20201108051730.2042693-16-dima@arista.com> (raw)
In-Reply-To: <20201108051730.2042693-1-dima@arista.com>
Generic way to track the land vma area.
As a bonus, after unmapping vdso, kernel won't try to land on its
previous position.
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
arch/x86/Kconfig | 1 +
arch/x86/entry/common.c | 3 ++-
arch/x86/entry/vdso/vma.c | 9 ++++-----
arch/x86/ia32/ia32_signal.c | 4 ++--
arch/x86/include/asm/mmu.h | 1 -
arch/x86/include/asm/vdso.h | 2 +-
arch/x86/kernel/signal.c | 4 ++--
7 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b068f949d2e4..2449844ef0e9 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -84,6 +84,7 @@ config X86
select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
select ARCH_HAS_SYSCALL_WRAPPER
select ARCH_HAS_UBSAN_SANITIZE_ALL
+ select ARCH_HAS_USER_LANDING
select ARCH_HAS_DEBUG_WX
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 1be1bdbe55d4..1a3f795af331 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -151,9 +151,10 @@ __visible noinstr long do_fast_syscall_32(struct pt_regs *regs)
* Called using the internal vDSO SYSENTER/SYSCALL32 calling
* convention. Adjust regs so it looks like we entered using int80.
*/
- landing_pad = (unsigned long)current->mm->context.vdso +
+ landing_pad = (unsigned long)current->mm->user_landing +
vdso_image_32.sym_int80_landing_pad;
+
/*
* SYSENTER loses EIP, and even SYSCALL32 needs us to skip forward
* so that 'regs->ip -= 2' lands back on an int $0x80 instruction.
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 65780a0164e3..2c426997a7a4 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -77,7 +77,7 @@ static void vdso_fix_landing(const struct vdso_image *image,
struct pt_regs *regs = current_pt_regs();
unsigned long vdso_land = image->sym_int80_landing_pad;
unsigned long old_land_addr = vdso_land +
- (unsigned long)current->mm->context.vdso;
+ (unsigned long)current->mm->user_landing;
/* Fixing userspace landing - look at do_fast_syscall_32 */
if (regs->ip == old_land_addr)
@@ -92,7 +92,6 @@ static void vdso_mremap(const struct vm_special_mapping *sm,
const struct vdso_image *image = current->mm->context.vdso_image;
vdso_fix_landing(image, new_vma);
- current->mm->context.vdso = (void __user *)new_vma->vm_start;
}
#ifdef CONFIG_TIME_NS
@@ -287,7 +286,7 @@ static int map_vdso(const struct vdso_image *image, unsigned long addr,
ret = PTR_ERR(vma);
do_munmap(mm, text_start, image->size, NULL);
} else {
- current->mm->context.vdso = (void __user *)text_start;
+ current->mm->user_landing = (void __user *)text_start;
current->mm->context.vdso_image = image;
*sysinfo_ehdr = text_start;
}
@@ -362,8 +361,8 @@ int map_vdso_once(const struct vdso_image *image, unsigned long addr)
* Check if we have already mapped vdso blob - fail to prevent
* abusing from userspace install_speciall_mapping, which may
* not do accounting and rlimit right.
- * We could search vma near context.vdso, but it's a slowpath,
- * so let's explicitly check all VMAs to be completely sure.
+ * It's a slowpath, let's explicitly check all VMAs to be
+ * completely sure.
*/
for (vma = mm->mmap; vma; vma = vma->vm_next) {
if (vma_is_special_mapping(vma, &vdso_mapping) ||
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index f87ed1d53938..fb84c0fcdc4e 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -256,7 +256,7 @@ int ia32_setup_frame(int sig, struct ksignal *ksig,
} else {
/* Return stub is in 32bit vsyscall page */
if (current_has_vdso_image_32())
- restorer = current->mm->context.vdso +
+ restorer = current->mm->user_landing +
vdso_image_32.sym___kernel_sigreturn;
else
restorer = &frame->retcode;
@@ -337,7 +337,7 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
if (ksig->ka.sa.sa_flags & SA_RESTORER)
restorer = ksig->ka.sa.sa_restorer;
else if (current_has_vdso_image_32())
- restorer = current->mm->context.vdso +
+ restorer = current->mm->user_landing +
vdso_image_32.sym___kernel_rt_sigreturn;
else
restorer = &frame->retcode;
diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h
index 5d7494631ea9..7bd10e6b8386 100644
--- a/arch/x86/include/asm/mmu.h
+++ b/arch/x86/include/asm/mmu.h
@@ -43,7 +43,6 @@ typedef struct {
#endif
struct mutex lock;
- void __user *vdso; /* vdso base address */
const struct vdso_image *vdso_image; /* vdso image in use */
atomic_t perf_rdpmc_allowed; /* nonzero if rdpmc is allowed */
diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
index a19e0a7bae2d..735ad9e563e1 100644
--- a/arch/x86/include/asm/vdso.h
+++ b/arch/x86/include/asm/vdso.h
@@ -42,7 +42,7 @@ extern const struct vdso_image vdso_image_32;
#define current_has_vdso_image_32() \
likely(current->mm->context.vdso_image == &vdso_image_32 && \
- !!current->mm->context.vdso)
+ (unsigned long)current->mm->user_landing != UNMAPPED_USER_LANDING)
#endif
extern void __init init_vdso_image(const struct vdso_image *image);
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 6fed2e523e0a..b18e6dd0a574 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -320,7 +320,7 @@ __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
if (ksig->ka.sa.sa_flags & SA_RESTORER)
restorer = ksig->ka.sa.sa_restorer;
else if (current_has_vdso_image_32())
- restorer = current->mm->context.vdso +
+ restorer = current->mm->user_landing +
vdso_image_32.sym___kernel_sigreturn;
else
restorer = &frame->retcode;
@@ -382,7 +382,7 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
if (ksig->ka.sa.sa_flags & SA_RESTORER)
restorer = ksig->ka.sa.sa_restorer;
else if (current_has_vdso_image_32())
- restorer = current->mm->context.vdso +
+ restorer = current->mm->user_landing +
vdso_image_32.sym___kernel_rt_sigreturn;
else
restorer = &frame->retcode;
--
2.28.0
next prev parent reply other threads:[~2020-11-08 5:18 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-08 5:17 [PATCH 00/19] Add generic user_landing tracking Dmitry Safonov
2020-11-08 5:17 ` [PATCH 01/19] x86/elf: Check in_x32_syscall() in compat_arch_setup_additional_pages() Dmitry Safonov
2020-11-08 5:17 ` [PATCH 02/19] elf: Move arch_setup_additional_pages() to generic elf.h Dmitry Safonov
2020-11-13 6:58 ` kernel test robot
2020-11-13 7:01 ` kernel test robot
2020-11-08 5:17 ` [PATCH 03/19] arm64: Use in_compat_task() in arch_setup_additional_pages() Dmitry Safonov
2020-11-08 5:17 ` [PATCH 04/19] x86: Remove compat_arch_setup_additional_pages() Dmitry Safonov
2020-11-08 5:17 ` [PATCH 05/19] elf: " Dmitry Safonov
2020-11-08 5:17 ` [PATCH 06/19] elf/vdso: Reuse arch_setup_additional_pages() parameters Dmitry Safonov
2020-11-13 6:57 ` kernel test robot
2020-11-13 8:04 ` kernel test robot
2020-11-08 5:17 ` [PATCH 07/19] elf: Use sysinfo_ehdr in ARCH_DLINFO() Dmitry Safonov
2020-11-08 5:17 ` [PATCH 08/19] arm/vdso: Remove vdso pointer from mm->context Dmitry Safonov
2020-11-08 5:17 ` [PATCH 09/19] s390/vdso: Remove vdso_base " Dmitry Safonov
2020-11-08 5:17 ` [PATCH 10/19] sparc/vdso: Remove vdso " Dmitry Safonov
2020-11-08 5:17 ` [PATCH 11/19] mm/mmap: Make vm_special_mapping::mremap return void Dmitry Safonov
2020-11-08 5:17 ` [PATCH 12/19] x86/signal: Land on &frame->retcode when vdso isn't mapped Dmitry Safonov
2020-11-08 19:06 ` Andy Lutomirski
2020-11-09 1:22 ` Dmitry Safonov
2020-11-08 5:17 ` [PATCH 13/19] x86/signal: Check if vdso_image_32 is mapped before trying to land on it Dmitry Safonov
2020-11-08 5:17 ` [PATCH 14/19] mm: Add user_landing in mm_struct Dmitry Safonov
2020-11-08 19:04 ` Andy Lutomirski
2020-11-09 1:25 ` Dmitry Safonov
2020-11-08 5:17 ` Dmitry Safonov [this message]
2020-11-08 5:17 ` [PATCH 16/19] arm/vdso: Migrate to user_landing Dmitry Safonov
2020-11-08 5:17 ` [PATCH 17/19] arm64/vdso: Migrate compat signals " Dmitry Safonov
2020-11-08 5:17 ` [PATCH 18/19] arm64/vdso: Migrate native " Dmitry Safonov
2020-11-08 5:17 ` [PATCH 19/19] mips/vdso: Migrate " Dmitry Safonov
2020-11-13 9:58 ` kernel test robot
2020-11-08 19:07 ` [PATCH 00/19] Add generic user_landing tracking Andy Lutomirski
2020-11-09 1:27 ` Dmitry Safonov
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