On 1/28/24 18:38, Bhumkar, Tejas Arvind wrote:
[AMD Official Use Only - General]
Hi Heinrich,
-----Original Message-----
From: Heinrich Schuchardt <xypron.g...@gmx.de>
Sent: Sunday, January 28, 2024 2:51 PM
To: Bhumkar, Tejas Arvind <tejas.arvind.bhum...@amd.com>
Cc: u-boot@lists.denx.de; tr...@konsulko.com; s...@chromium.org; Simek, Michal
<michal.si...@amd.com>; Abbarapu, Venkatesh
<venkatesh.abbar...@amd.com>; g...@xilinx.com; Ilias Apalodimas
<ilias.apalodi...@linaro.org>
Subject: Re: [PATCH] efi_loader : Suppress error print message
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On 1/28/24 06:20, Bhumkar, Tejas Arvind wrote:
[AMD Official Use Only - General]
Hi Heinrich,
-----Original Message-----
From: Heinrich Schuchardt <xypron.g...@gmx.de>
Sent: Wednesday, January 24, 2024 2:09 AM
To: Bhumkar, Tejas Arvind <tejas.arvind.bhum...@amd.com>
Cc: u-boot@lists.denx.de; tr...@konsulko.com; s...@chromium.org;
Simek, Michal <michal.si...@amd.com>; Abbarapu, Venkatesh
<venkatesh.abbar...@amd.com>; g...@xilinx.com; Ilias Apalodimas
<ilias.apalodi...@linaro.org>
Subject: Re: [PATCH] efi_loader : Suppress error print message
Caution: This message originated from an External Source. Use proper
caution when opening attachments, clicking links, or responding.
On 1/23/24 19:53, Bhumkar, Tejas Arvind wrote:
[AMD Official Use Only - General]
Hi Ilias & Heinrich,
-----Original Message-----
From: Heinrich Schuchardt <xypron.g...@gmx.de>
Sent: Tuesday, January 23, 2024 3:30 PM
To: Ilias Apalodimas <ilias.apalodi...@linaro.org>; Bhumkar, Tejas
Arvind <tejas.arvind.bhum...@amd.com>
Cc: u-boot@lists.denx.de; xypron.g...@gmx.de; tr...@konsulko.com;
s...@chromium.org; Simek, Michal <michal.si...@amd.com>; Abbarapu,
Venkatesh <venkatesh.abbar...@amd.com>; g...@xilinx.com
Subject: Re: [PATCH] efi_loader : Suppress error print message
Caution: This message originated from an External Source. Use
proper caution when opening attachments, clicking links, or responding.
On 1/23/24 09:33, Ilias Apalodimas wrote:
Hi Tejas,
On Mon, 22 Jan 2024 at 21:12, Tejas Bhumkar
<tejas.arvind.bhum...@amd.com> wrote:
Currently, on certain Xilinx platforms, an issue has been
identified, manifesting as follows:
Hello Tejas,
thank you for bringing forward this issue.
Which defconfig are you relating to?
[Tejas]:
Checking with xilinx_zynqmp_virt_defconfig
Starting kernel ...
efi_free_pool: illegal free 0x0000000077830040
efi_free_pool: illegal free 0x000000007782d040
efi_free_pool: illegal free 0x000000007782c040
The issue arises when the ramdisk image is relocated, placing it
within the previously allocated EFI memory region( as EFI is
established quite early in U-Boot).
Which version of U-Boot are you on? Commit 06d514d77c37 ("lmb:
consider EFI memory map") was meant to avoid such a situation.
[Tejas] :
I'm verifying against the latest changes in the master branch. The
introduction of commit 06d514d77c37 ("lmb: consider EFI memory map")
has resolved the occurrence of the "efi_free_pool: illegal free"
error. but, it leads to a new error, as detailed in the following
patch:
https://lore.kernel.org/all/20230212150706.2967007-1-sjoerd@collabora.
com/
Could you, please, try to reproduce your issues with origin/master as
of today and provide the full boot log. Please, also provide the
output of the bdinfo and the printenv command as well as the sizes of the
kernel and the RAM disk.
[Tejas]: I've provided two logs: one obtained from the latest u-boot
origin/master, resulting in the "ERROR: reserving fdt memory region failed"
error,
and the other from reverting commit 06d514d77c37 ("lmb: consider EFI memory
map"), which leads to the "efi_free_pool: illegal free" error.
Thank You,
Tejas.
Where can I find these logs?
[Tejas ] : I've sent the attachment in a previous email. I'm not sure why you
didn't receive it.
I've attached it again now. Please confirm if you still haven't received it.
Thank You,
Tejas.
If I understand your FDT_memory_region_failed.log correctly:
Except for some added debug messages this log matches booting with an
unmodified upstream U-Boot as of Jan 22nd.
Your memory is split into two regions:
0x0 - 0x7ffffff and
0x800000000 - 0x87ffffff.
Your device-tree has a reserved region 0x7ff00000-0x7fffffff.
U-Boot relocates itself into the lower memory block due to current design.
efi_lmb_reserve() marks memory up to 0x7fffffff and
0x800000000-0x87fffffff as reserved.
boot_fdt_reserve_region() writes an error when it tries to reserve the
overlapping region 0x7ff00000-0x7fffffff because LMB recognizes this
region is already reserved.
This should not interfere with booting as boot_fdt_reserve_region() does
not have a return value but is not very clean and should be fixed.
Best regards
Heinrich
I don't mind suppressing the print for some time, but out of
curiosity, how is the ramdisk relocated? LMB should be aware of
the EFI regions by then, so I assume the relocation code doesn't
check those?
[Tejas] : I observe that the relocation of the RAM disk is taking
place in the line
below.
https://github.com/u-boot/u-boot/blob/master/lib/lmb.c#L480-L491
Yes, the relocated code specifically examines the LMB region and
does not
consider the EFI region.
The indicated situation is serious. If the EFI sub-system is using
the same memory area as the ramdisk, this may lead to corruption of
the ramdisk. Suppressing the messages is by no means adequate to
solve the
problem.
[Tejas] :
The challenge arises when relocating the ramdisk image, inserting it
into the previously assigned EFI memory region, established early in
U-Boot. Consequently, when attempting to release memory in the EFI
region
during the handover process to the kernel in the efi_free_pool
function, we first verify if the memory was allocated by efi_allocate_pool().
The issue originates from a checksum mismatch because, during the
ramdisk
relocation, we overwrite memory allocated by EFI.
This leads to the appearance of the error message: efi_free_pool:
illegal free
0x0000000077830040.
Crucially, there is no corruption of the ramdisk seen since we do
not actually
releasing memory due to the checksum mismatch.
In our testing, this issue was observed only when the ramdisk size
exceeded
approximately 24 MB.
Best regards
Heinrich
Thanks
/Ilias
Consequently, when
attempting to release memory in the EFI memory region during the
handover process to the kernel,we encounter memory violations.
Highlighting that EFI remains active primarily during the booting
of an EFI application, and the lmb persists while configuring
images for the boot process. Since we aren't utilizing the EFI
memory region during the boot process, there is no adverse impact
even in the event of a violation.
Currently, there is an ongoing discussion regarding the handling
strategies of three memory allocators: malloc, lmb, and EFI. This
discussion is documented in the email chain titled "Proposal:
U-Boot memory management."
Therefore, it is advisable to suppress the print message during
the boot process for now.
Signed-off-by: Tejas Bhumkar <tejas.arvind.bhum...@amd.com>
---
lib/efi_loader/efi_memory.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/efi_loader/efi_memory.c
b/lib/efi_loader/efi_memory.c index edfad2d95a..821fe7616e 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -713,7 +713,7 @@ efi_status_t efi_free_pool(void *buffer)
/* Check that this memory was allocated by efi_allocate_pool() */
if (((uintptr_t)alloc & EFI_PAGE_MASK) ||
alloc->checksum != checksum(alloc)) {
- printf("%s: illegal free 0x%p\n", __func__, buffer);
+ debug("%s: illegal free 0x%p\n", __func__,
+ buffer);
return EFI_INVALID_PARAMETER;
}
/* Avoid double free */
--
2.27.0
