From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Rini Date: Thu, 10 Sep 2020 09:50:52 -0400 Subject: [PATCH v3 4/4] arm64: Trap non-PIE builds early if starting from wrong address In-Reply-To: <6221239e-e459-859a-5770-ea987e164640@xilinx.com> References: <20200909170727.658573-1-edgar.iglesias@gmail.com> <20200909170727.658573-5-edgar.iglesias@gmail.com> <27b8fa20-fc4a-0a56-940b-40d3e740d9f0@xilinx.com> <6221239e-e459-859a-5770-ea987e164640@xilinx.com> Message-ID: <20200910135052.GY7259@bill-the-cat> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Thu, Sep 10, 2020 at 03:38:25PM +0200, Michal Simek wrote: > > > On 10. 09. 20 15:06, Andr? Przywara wrote: > > On 10/09/2020 13:38, Michal Simek wrote: > >> > >> > >> On 09. 09. 20 19:07, Edgar E. Iglesias wrote: > >>> From: "Edgar E. Iglesias" > >>> > >>> Trap non-PIE builds early if the start address doesn't match > >>> between run-time and link-time. This will trap the startup > >>> sequence rather than letting it run into obscure errors. > >>> > >>> Signed-off-by: Edgar E. Iglesias > >>> --- > >>> arch/arm/cpu/armv8/start.S | 13 +++++++++++++ > >>> 1 file changed, 13 insertions(+) > >>> > >>> diff --git a/arch/arm/cpu/armv8/start.S b/arch/arm/cpu/armv8/start.S > >>> index e5c2856cf5..39e1b842c4 100644 > >>> --- a/arch/arm/cpu/armv8/start.S > >>> +++ b/arch/arm/cpu/armv8/start.S > >>> @@ -101,6 +101,19 @@ pie_skip_reloc: > >>> cmp x2, x3 > >>> b.lo pie_fix_loop > >>> pie_fixup_done: > >>> +#else > >>> + adr x0, _start > >>> + ldr x1, _TEXT_BASE > >>> + cmp x0, x1 > >>> + beq 1f > >>> +0: > >>> + /* > >>> + * FATAL, can't continue. > >>> + * U-Boot needs to start executing at CONFIG_SYS_TEXT_BASE. > >>> + */ > >>> + wfi > >>> + b 0b > >>> +1: > >>> #endif > >>> > >>> #ifdef CONFIG_SYS_RESET_SCTRL > >>> > >> > >> NACK for this. > >> > >> 1. It breaks SPL flow because CONFIG_SYS_TEXT_BASE is text base for > >> U-Boot proper > >> 2. It likely also breaks TPL flow for the same reason > >> > >> 3. And last thing is that this code is used only for U-Boot proper. > >> .globl _TEXT_BASE > >> _TEXT_BASE: > >> .quad CONFIG_SYS_TEXT_BASE > >> > >> The fixes are below. Point 3 should be likely be in separate patch > >> because it is unrelated. > > > > So if this patch causes issues, can't we just drop it? I mean right now > > you will probably just crash anyway if you load it at the wrong address, > > but maybe late enough that you get more hints or even some output. > > > > Now this patch makes sure that you don't get anything, so I don't see > > how this is really improving the situation. It seems like a case of > > "don't fix things that ain't broken". > > I am fine with dropping it. > Tom: What do you think? OK, yes, we can set this aside for now at least. I assume this is all for v2021.01 anyhow? -- Tom -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 659 bytes Desc: not available URL: