From: Joerg Roedel <joro@8bytes.org>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>, "H . Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>,
Dave Hansen <dave.hansen@intel.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Juergen Gross <jgross@suse.com>,
Peter Zijlstra <peterz@infradead.org>,
Borislav Petkov <bp@alien8.de>, Jiri Kosina <jkosina@suse.cz>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Brian Gerst <brgerst@gmail.com>,
David Laight <David.Laight@aculab.com>,
Denys Vlasenko <dvlasenk@redhat.com>,
Eduardo Valentin <eduval@amazon.com>,
Greg KH <gregkh@linuxfoundation.org>,
Will Deacon <will.deacon@arm.com>,
aliguori@amazon.com, daniel.gruss@iaik.tugraz.at,
hughd@google.com, keescook@google.com,
Andrea Arcangeli <aarcange@redhat.com>,
Waiman Long <llong@redhat.com>, Pavel Machek <pavel@ucw.cz>,
"David H . Gutteridge" <dhgutteridge@sympatico.ca>,
jroedel@suse.de, joro@8bytes.org
Subject: [PATCH 12/37] x86/32: Use tss.sp1 as cpu_current_top_of_stack
Date: Mon, 23 Apr 2018 17:47:15 +0200 [thread overview]
Message-ID: <1524498460-25530-13-git-send-email-joro@8bytes.org> (raw)
In-Reply-To: <1524498460-25530-1-git-send-email-joro@8bytes.org>
From: Joerg Roedel <jroedel@suse.de>
Now that we store the task-stack in tss.sp1 we can also use
it as cpu_current_top_of_stack. This unifies the handling
with x86-64.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
arch/x86/include/asm/processor.h | 4 ----
arch/x86/include/asm/thread_info.h | 2 --
arch/x86/kernel/cpu/common.c | 4 ----
arch/x86/kernel/process_32.c | 6 ------
4 files changed, 16 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 21a1149..d65e852 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -374,12 +374,8 @@ DECLARE_PER_CPU_PAGE_ALIGNED(struct tss_struct, cpu_tss_rw);
#define __KERNEL_TSS_LIMIT \
(IO_BITMAP_OFFSET + IO_BITMAP_BYTES + sizeof(unsigned long) - 1)
-#ifdef CONFIG_X86_32
-DECLARE_PER_CPU(unsigned long, cpu_current_top_of_stack);
-#else
/* The RO copy can't be accessed with this_cpu_xyz(), so use the RW copy. */
#define cpu_current_top_of_stack cpu_tss_rw.x86_tss.sp1
-#endif
/*
* Save the original ist values for checking stack pointers during debugging
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index a5d9521..943c673 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -205,9 +205,7 @@ static inline int arch_within_stack_frames(const void * const stack,
#else /* !__ASSEMBLY__ */
-#ifdef CONFIG_X86_64
# define cpu_current_top_of_stack (cpu_tss_rw + TSS_sp1)
-#endif
#endif
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 311e988..2d67ad0 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1512,10 +1512,6 @@ EXPORT_PER_CPU_SYMBOL(__preempt_count);
* the top of the kernel stack. Use an extra percpu variable to track the
* top of the kernel stack directly.
*/
-DEFINE_PER_CPU(unsigned long, cpu_current_top_of_stack) =
- (unsigned long)&init_thread_union + THREAD_SIZE;
-EXPORT_PER_CPU_SYMBOL(cpu_current_top_of_stack);
-
#ifdef CONFIG_CC_STACKPROTECTOR
DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
#endif
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 3f3a8c6..8c29fd5 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -290,12 +290,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
update_sp0(next_p);
refresh_sysenter_cs(next);
this_cpu_write(cpu_current_top_of_stack, task_top_of_stack(next_p));
- /*
- * TODO: Find a way to let cpu_current_top_of_stack point to
- * cpu_tss_rw.x86_tss.sp1. Doing so now results in stack corruption with
- * iret exceptions.
- */
- this_cpu_write(cpu_tss_rw.x86_tss.sp1, next_p->thread.sp0);
/*
* Restore %gs if needed (which is common)
--
2.7.4
next prev parent reply other threads:[~2018-04-23 15:47 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-23 15:47 [PATCH 00/37 v6] PTI support for x86-32 Joerg Roedel
2018-04-23 15:47 ` [PATCH 01/37] x86/asm-offsets: Move TSS_sp0 and TSS_sp1 to asm-offsets.c Joerg Roedel
2018-04-23 15:47 ` [PATCH 02/37] x86/entry/32: Rename TSS_sysenter_sp0 to TSS_entry_stack Joerg Roedel
2018-04-23 15:47 ` [PATCH 03/37] x86/entry/32: Load task stack from x86_tss.sp1 in SYSENTER handler Joerg Roedel
2018-04-23 15:47 ` [PATCH 04/37] x86/entry/32: Put ESPFIX code into a macro Joerg Roedel
2018-04-23 15:47 ` [PATCH 05/37] x86/entry/32: Unshare NMI return path Joerg Roedel
2018-04-23 15:47 ` [PATCH 06/37] x86/entry/32: Split off return-to-kernel path Joerg Roedel
2018-04-23 15:47 ` [PATCH 07/37] x86/entry/32: Enter the kernel via trampoline stack Joerg Roedel
2018-04-23 15:47 ` [PATCH 08/37] x86/entry/32: Leave " Joerg Roedel
2018-04-23 15:47 ` [PATCH 09/37] x86/entry/32: Introduce SAVE_ALL_NMI and RESTORE_ALL_NMI Joerg Roedel
2018-04-23 15:47 ` [PATCH 10/37] x86/entry/32: Handle Entry from Kernel-Mode on Entry-Stack Joerg Roedel
2018-04-23 15:47 ` [PATCH 11/37] x86/entry/32: Simplify debug entry point Joerg Roedel
2018-04-23 15:47 ` Joerg Roedel [this message]
2018-04-23 15:47 ` [PATCH 13/37] x86/entry/32: Add PTI cr3 switch to non-NMI entry/exit points Joerg Roedel
2018-04-23 15:47 ` [PATCH 14/37] x86/entry/32: Add PTI cr3 switches to NMI handler code Joerg Roedel
2018-04-23 15:47 ` [PATCH 15/37] x86/pgtable: Rename pti_set_user_pgd to pti_set_user_pgtbl Joerg Roedel
2018-04-23 15:47 ` [PATCH 16/37] x86/pgtable/pae: Unshare kernel PMDs when PTI is enabled Joerg Roedel
2018-04-23 15:47 ` [PATCH 17/37] x86/pgtable/32: Allocate 8k page-tables " Joerg Roedel
2018-04-23 15:47 ` [PATCH 18/37] x86/pgtable: Move pgdp kernel/user conversion functions to pgtable.h Joerg Roedel
2018-04-23 15:47 ` [PATCH 19/37] x86/pgtable: Move pti_set_user_pgtbl() " Joerg Roedel
2018-04-23 15:47 ` [PATCH 20/37] x86/pgtable: Move two more functions from pgtable_64.h " Joerg Roedel
2018-04-23 15:47 ` [PATCH 21/37] x86/mm/pae: Populate valid user PGD entries Joerg Roedel
2018-04-23 15:47 ` [PATCH 22/37] x86/mm/pae: Populate the user page-table with user pgd's Joerg Roedel
2018-04-23 15:47 ` [PATCH 23/37] x86/mm/legacy: " Joerg Roedel
2018-04-23 15:47 ` [PATCH 24/37] x86/mm/pti: Add an overflow check to pti_clone_pmds() Joerg Roedel
2018-04-23 15:47 ` [PATCH 25/37] x86/mm/pti: Define X86_CR3_PTI_PCID_USER_BIT on x86_32 Joerg Roedel
2018-04-23 15:47 ` [PATCH 26/37] x86/mm/pti: Clone CPU_ENTRY_AREA on PMD level " Joerg Roedel
2018-04-23 15:47 ` [PATCH 27/37] x86/mm/pti: Keep permissions when cloning kernel text in pti_clone_kernel_text() Joerg Roedel
2018-04-23 17:06 ` Kees Cook
2018-04-23 18:00 ` Joerg Roedel
2018-04-23 15:47 ` [PATCH 28/37] x86/mm/pti: Map kernel-text to user-space on 32 bit kernels Joerg Roedel
2018-04-23 17:09 ` Kees Cook
2018-04-23 17:48 ` Joerg Roedel
2018-04-23 15:47 ` [PATCH 29/37] x86/mm/dump_pagetables: Define INIT_PGD Joerg Roedel
2018-04-23 15:47 ` [PATCH 30/37] x86/pgtable/pae: Use separate kernel PMDs for user page-table Joerg Roedel
2018-04-23 15:47 ` [PATCH 31/37] x86/ldt: Reserve address-space range on 32 bit for the LDT Joerg Roedel
2018-04-23 15:47 ` [PATCH 32/37] x86/ldt: Define LDT_END_ADDR Joerg Roedel
2018-04-23 15:47 ` [PATCH 33/37] x86/ldt: Split out sanity check in map_ldt_struct() Joerg Roedel
2018-04-23 15:47 ` [PATCH 34/37] x86/ldt: Enable LDT user-mapping for PAE Joerg Roedel
2018-04-23 15:47 ` [PATCH 35/37] x86/pti: Allow CONFIG_PAGE_TABLE_ISOLATION for x86_32 Joerg Roedel
2018-04-23 15:47 ` [PATCH 36/37] x86/mm/pti: Add Warning when booting on a PCID capable CPU Joerg Roedel
2018-04-23 15:47 ` [PATCH 37/37] x86/entry/32: Add debug code to check entry/exit cr3 Joerg Roedel
2018-04-23 16:45 ` [PATCH 00/37 v6] PTI support for x86-32 Linus Torvalds
2018-04-23 17:45 ` Joerg Roedel
2018-04-23 17:49 ` Linus Torvalds
2018-04-23 19:38 ` Pavel Machek
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