From: Lai Jiangshan <jiangshanlai@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: x86@kernel.org, Lai Jiangshan <laijs@linux.alibaba.com>,
Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
Sean Christopherson <seanjc@google.com>
Subject: [PATCH V3 18/49] x86/traps: Move pt_regs only in fixup_bad_iret()
Date: Thu, 14 Oct 2021 11:33:41 +0800 [thread overview]
Message-ID: <20211014033414.16321-13-jiangshanlai@gmail.com> (raw)
In-Reply-To: <20211014031413.14471-1-jiangshanlai@gmail.com>
From: Lai Jiangshan <laijs@linux.alibaba.com>
Make fixup_bad_iret() works like sync_regs() which doesn't
move the return address of error_entry().
It is prepared later patch which implements the body of error_entry()
in C code. The fixup_bad_iret() can't handle return address when it
is called from C code.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
---
arch/x86/entry/entry_64.S | 5 ++++-
arch/x86/include/asm/traps.h | 2 +-
arch/x86/kernel/traps.c | 17 ++++++-----------
3 files changed, 11 insertions(+), 13 deletions(-)
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index daaeeb8acd22..7f2338c3b676 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1047,9 +1047,12 @@ SYM_CODE_START_LOCAL(error_entry)
* Pretend that the exception came from user mode: set up pt_regs
* as if we faulted immediately after IRET.
*/
- mov %rsp, %rdi
+ popq %r12 /* save return addr in %12 */
+ movq %rsp, %rdi /* arg0 = pt_regs pointer */
call fixup_bad_iret
mov %rax, %rsp
+ ENCODE_FRAME_POINTER
+ pushq %r12
jmp .Lerror_entry_from_usermode_after_swapgs
SYM_CODE_END(error_entry)
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 6221be7cafc3..1cdd7e8bcba7 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -13,7 +13,7 @@
#ifdef CONFIG_X86_64
asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs);
asmlinkage __visible notrace
-struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s);
+struct pt_regs *fixup_bad_iret(struct pt_regs *bad_regs);
void __init trap_init(void);
asmlinkage __visible noinstr struct pt_regs *vc_switch_off_ist(struct pt_regs *eregs);
#endif
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index cf852b5e347f..0afa16ea3702 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -759,13 +759,8 @@ asmlinkage __visible noinstr struct pt_regs *vc_switch_off_ist(struct pt_regs *r
}
#endif
-struct bad_iret_stack {
- void *error_entry_ret;
- struct pt_regs regs;
-};
-
asmlinkage __visible noinstr
-struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s)
+struct pt_regs *fixup_bad_iret(struct pt_regs *bad_regs)
{
/*
* This is called from entry_64.S early in handling a fault
@@ -775,19 +770,19 @@ struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s)
* just below the IRET frame) and we want to pretend that the
* exception came from the IRET target.
*/
- struct bad_iret_stack tmp, *new_stack =
- (struct bad_iret_stack *)__this_cpu_read(cpu_tss_rw.x86_tss.sp0) - 1;
+ struct pt_regs tmp, *new_stack =
+ (struct pt_regs *)__this_cpu_read(cpu_tss_rw.x86_tss.sp0) - 1;
/* Copy the IRET target to the temporary storage. */
- __memcpy(&tmp.regs.ip, (void *)s->regs.sp, 5*8);
+ __memcpy(&tmp.ip, (void *)bad_regs->sp, 5*8);
/* Copy the remainder of the stack from the current stack. */
- __memcpy(&tmp, s, offsetof(struct bad_iret_stack, regs.ip));
+ __memcpy(&tmp, bad_regs, offsetof(struct pt_regs, ip));
/* Update the entry stack */
__memcpy(new_stack, &tmp, sizeof(tmp));
- BUG_ON(!user_mode(&new_stack->regs));
+ BUG_ON(!user_mode(new_stack));
return new_stack;
}
#endif
--
2.19.1.6.gb485710b
next prev parent reply other threads:[~2021-10-14 3:35 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-14 3:13 [PATCH V3 00/49] x86/entry/64: Convert a bunch of ASM entry code into C code Lai Jiangshan
2021-10-14 3:13 ` [PATCH V3 01/49] x86/entry: Add fence for kernel entry swapgs in paranoid_entry() Lai Jiangshan
2021-10-14 3:13 ` [PATCH V3 02/49] x86/entry: Use the correct fence macro after swapgs in kernel CR3 Lai Jiangshan
2021-10-14 3:13 ` [PATCH V3 03/49] x86/traps: Remove stack-protector from traps.c Lai Jiangshan
2021-10-14 3:13 ` [PATCH V3 04/49] x86/xen: Add xenpv_restore_regs_and_return_to_usermode() Lai Jiangshan
2021-10-16 18:08 ` Boris Ostrovsky
2021-10-14 3:13 ` [PATCH V3 05/49] x86/entry: Use swapgs and native_iret directly in swapgs_restore_regs_and_return_to_usermode Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 06/49] compiler_types.h: Add __noinstr_section() for noinstr Lai Jiangshan
2021-10-14 18:29 ` Nick Desaulniers
2021-10-14 18:35 ` Miguel Ojeda
2021-10-18 9:16 ` Lai Jiangshan
2021-10-18 11:29 ` Miguel Ojeda
2021-10-14 3:33 ` [PATCH V3 07/49] x86/entry: Introduce __entry_text for entry code written in C Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 08/49] x86/entry: Move PTI_USER_* to arch/x86/include/asm/processor-flags.h Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 09/49] x86: Remove unused kernel_to_user_p4dp() and user_to_kernel_p4dp() Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 10/49] x86: Replace PTI_PGTABLE_SWITCH_BIT with PTI_USER_PGTABLE_BIT Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 11/49] x86: Mark __native_read_cr3() & native_write_cr3() as __always_inline Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 12/49] x86/traps: Move the declaration of native_irq_return_iret into proto.h Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 13/49] x86/entry: Add arch/x86/entry/entry64.c for C entry code Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 14/49] x86/entry: Expose the address of .Lgs_change to entry64.c Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 15/49] x86/entry: Add C verion of SWITCH_TO_KERNEL_CR3 as switch_to_kernel_cr3() Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 16/49] x86/traps: Add fence_swapgs_{user,kernel}_entry() Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 17/49] x86/entry: Add C {user,kernel}_entry_swapgs_and_fence() Lai Jiangshan
2021-10-14 3:33 ` Lai Jiangshan [this message]
2021-10-14 3:33 ` [PATCH V3 19/49] x86/entry: Switch the stack after error_entry() returns Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 20/49] x86/entry: move PUSH_AND_CLEAR_REGS out of error_entry Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 21/49] x86/entry: Move cld to the start of idtentry Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 22/49] x86/entry: Don't call error_entry for XENPV Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 23/49] x86/entry: Convert SWAPGS to swapgs in error_entry() Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 24/49] x86/entry: Implement the whole error_entry() as C code Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 25/49] x86/entry: Use idtentry macro for entry_INT80_compat Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 26/49] x86/entry: Convert SWAPGS to swapgs in entry_SYSENTER_compat() Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 27/49] x86: Remove the definition of SWAPGS Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 28/49] x86/entry: Make paranoid_exit() callable Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 29/49] x86/entry: Call paranoid_exit() in asm_exc_nmi() Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 30/49] x86/entry: move PUSH_AND_CLEAR_REGS out of paranoid_entry Lai Jiangshan
2021-10-14 3:33 ` [PATCH V3 31/49] x86/entry: Add the C version ist_switch_to_kernel_cr3() Lai Jiangshan
2021-10-14 3:41 ` [PATCH V3 32/49] x86/entry: Add the C version ist_restore_cr3() Lai Jiangshan
2021-10-25 0:34 ` Lai Jiangshan
2021-10-14 3:41 ` [PATCH V3 33/49] x86/entry: Add the C version get_percpu_base() Lai Jiangshan
2021-10-14 3:41 ` [PATCH V3 34/49] x86/entry: Add the C version ist_switch_to_kernel_gsbase() Lai Jiangshan
2021-10-14 3:41 ` [PATCH V3 35/49] x86/entry: Implement the C version ist_paranoid_entry() Lai Jiangshan
2021-10-14 3:50 ` [PATCH V3 36/49] x86/entry: Implement the C version ist_paranoid_exit() Lai Jiangshan
2021-10-14 3:50 ` [PATCH V3 37/49] x86/entry: Add a C macro to define the function body for IST in .entry.text Lai Jiangshan
2021-10-14 3:50 ` [PATCH V3 38/49] x86/debug, mce: Use C entry code Lai Jiangshan
2021-10-14 3:50 ` [PATCH V3 39/49] x86/idtentry.h: Move the definitions *IDTENTRY_{MCE|DEBUG}* up Lai Jiangshan
2021-10-14 3:50 ` [PATCH V3 40/49] x86/nmi: Use DEFINE_IDTENTRY_NMI for nmi Lai Jiangshan
2021-10-14 3:50 ` [PATCH V3 41/49] x86/nmi: Use C entry code Lai Jiangshan
2021-10-14 3:50 ` [PATCH V3 42/49] x86/entry: Add a C macro to define the function body for IST in .entry.text with an error code Lai Jiangshan
2021-10-14 3:58 ` [PATCH V3 43/49] x86/doublefault: Use C entry code Lai Jiangshan
2021-10-14 3:58 ` [PATCH V3 44/49] x86/sev: Add and use ist_vc_switch_off_ist() Lai Jiangshan
2021-10-14 3:58 ` [PATCH V3 45/49] x86/sev: Use C entry code Lai Jiangshan
2021-10-14 3:58 ` [PATCH V3 46/49] x86/entry: Remove ASM function paranoid_entry() and paranoid_exit() Lai Jiangshan
2021-10-14 3:58 ` [PATCH V3 47/49] x86/entry: Remove the unused ASM macros Lai Jiangshan
2021-10-14 3:58 ` [PATCH V3 48/49] x86/entry: Remove save_ret from PUSH_AND_CLEAR_REGS Lai Jiangshan
2021-10-14 3:58 ` [PATCH V3 49/49] x86/syscall/64: Move the checking for sysret to C code Lai Jiangshan
2021-10-23 0:01 ` [PATCH V3 00/49] x86/entry/64: Convert a bunch of ASM entry code into " Lai Jiangshan
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