From: Lai Jiangshan <laijs@linux.alibaba.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>,
linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Joerg Roedel <jroedel@suse.de>,
Javier Martinez Canillas <javierm@redhat.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Brijesh Singh <brijesh.singh@amd.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Arvind Sankar <nivedita@alum.mit.edu>,
Juergen Gross <jgross@suse.com>, Chester Lin <clin@suse.com>
Subject: Re: [PATCH V2 02/41] x86/traps: Remove stack-protector from traps.c
Date: Mon, 27 Sep 2021 22:38:34 +0800 [thread overview]
Message-ID: <fb9b6013-8281-9864-d48f-e23ca651a20d@linux.alibaba.com> (raw)
In-Reply-To: <YVGkhlaDBwASW7dZ@zn.tnic>
On 2021/9/27 19:01, Borislav Petkov wrote:
> On Mon, Sep 27, 2021 at 06:49:16PM +0800, Lai Jiangshan wrote:
>> Using only "-fno-stack-protector" is enough to disable stack protector with
>> my .config, I'm not so sure about other configuration.
>
> What does the gcc manpage say about it?
>
In gcc's code, all the -f[no-]stack-protector* argument overwrites the
same flag_stack_protect variable, so the last one takes effect.
> fstack-protector
> Common Var(flag_stack_protect, 1) Init(-1) Optimization
> Use propolice as a stack protection method.
>
> fstack-protector-all
> Common RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
> Use a stack protection method for every function.
>
> fstack-protector-strong
> Common RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
> Use a smart stack protection method for certain functions.
>
> fstack-protector-explicit
> Common RejectNegative Var(flag_stack_protect, 4) Optimization
> Use stack protection method only for functions with the stack_protect attribute.
In linux kernel's scripts/Makefile.lib, CFLAGS_traps.o is the last flags for
gcc invocation, so only "CFLAGS_traps.o += -fno-stack-protector" must be enough.
> _c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \
> $(filter-out $(ccflags-remove-y), \
> $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \
> $(CFLAGS_$(target-stem).o))
next prev parent reply other threads:[~2021-09-27 14:38 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-26 15:07 [PATCH V2 00/41] x86/entry/64: Convert a bunch of ASM entry code into C code Lai Jiangshan
2021-09-26 15:07 ` [PATCH V2 01/41] x86/entry: Fix swapgs fence Lai Jiangshan
2021-09-26 20:43 ` Thomas Gleixner
2021-09-27 1:10 ` Lai Jiangshan
2021-09-27 3:27 ` Lai Jiangshan
2021-09-27 7:50 ` Thomas Gleixner
2021-09-26 15:07 ` [PATCH V2 02/41] x86/traps: Remove stack-protector from traps.c Lai Jiangshan
2021-09-27 10:19 ` Borislav Petkov
2021-09-27 10:49 ` Lai Jiangshan
2021-09-27 11:01 ` Borislav Petkov
2021-09-27 14:38 ` Lai Jiangshan [this message]
2021-09-26 15:08 ` [PATCH V2 03/41] compiler_types.h: Add __noinstr_section() for noinstr Lai Jiangshan
2021-09-27 18:09 ` Kees Cook
2021-09-26 15:08 ` [PATCH V2 04/41] x86/entry: Introduce __entry_text for entry code written in C Lai Jiangshan
2021-09-30 11:49 ` Borislav Petkov
2021-09-26 15:08 ` [PATCH V2 05/41] x86/entry: Move PTI_USER_* to arch/x86/include/asm/processor-flags.h Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 06/41] x86: Mark __native_read_cr3() & native_write_cr3() as __always_inline Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 07/41] x86/traps: Move the declaration of native_irq_return_iret into proto.h Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 08/41] x86/entry: Add arch/x86/entry/entry64.c for C entry code Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 09/41] x86/entry: Expose the address of .Lgs_change to entry64.c Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 10/41] x86/entry: Add C verion of SWITCH_TO_KERNEL_CR3 as switch_to_kernel_cr3() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 11/41] x86/entry: Add C user_entry_swapgs_and_fence() and kernel_entry_fence_no_swapgs() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 12/41] x86/traps: Move pt_regs only in fixup_bad_iret() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 13/41] x86/entry: Switch the stack after error_entry() returns Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 14/41] x86/entry: move PUSH_AND_CLEAR_REGS out of error_entry Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 15/41] objtool: Allow .entry.text function using CLD instruction Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 16/41] x86/entry: Implement the whole error_entry() as C code Lai Jiangshan
2021-09-28 21:34 ` Brian Gerst
2021-09-29 8:45 ` Peter Zijlstra
2021-09-26 15:08 ` [PATCH V2 17/41] x86/entry: Make paranoid_exit() callable Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 18/41] x86/entry: Call paranoid_exit() in asm_exc_nmi() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 19/41] x86/entry: move PUSH_AND_CLEAR_REGS out of paranoid_entry Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 20/41] x86/entry: Add the C version ist_switch_to_kernel_cr3() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 21/41] x86/entry: Add the C version ist_restore_cr3() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 22/41] x86/entry: Add the C version get_percpu_base() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 23/41] x86/entry: Add the C version ist_switch_to_kernel_gsbase() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 24/41] x86/entry: Implement the C version ist_paranoid_entry() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 25/41] x86/entry: Implement the C version ist_paranoid_exit() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 26/41] x86/entry: Add a C macro to define the function body for IST in .entry.text Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 27/41] x86/mce: Remove stack protector from mce/core.c Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 28/41] x86/debug, mce: Use C entry code Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 29/41] x86/idtentry.h: Move the definitions *IDTENTRY_{MCE|DEBUG}* up Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 30/41] x86/nmi: Use DEFINE_IDTENTRY_NMI for nmi Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 31/41] x86/nmi: Remove stack protector from nmi.c Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 32/41] x86/nmi: Use C entry code Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 33/41] x86/entry: Add a C macro to define the function body for IST in .entry.text with an error code Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 34/41] x86/doublefault: Use C entry code Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 35/41] x86/sev: Add and use ist_vc_switch_off_ist() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 36/41] x86/sev: Remove stack protector from sev.c Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 37/41] x86/sev: Use C entry code Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 38/41] x86/entry: Remove ASM function paranoid_entry() and paranoid_exit() Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 39/41] x86/entry: Remove the unused ASM macros Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 40/41] x86/entry: Remove save_ret from PUSH_AND_CLEAR_REGS Lai Jiangshan
2021-09-26 15:08 ` [PATCH V2 41/41] x86/syscall/64: Move the checking for sysret to C code Lai Jiangshan
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