| Message ID | 20220623094608.7294-4-jgross@suse.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | x86: fix brk area initialization | expand |
On Thu, Jun 23, 2022 at 11:46:08AM +0200, Juergen Gross wrote: > Commit e32683c6f7d2 ("x86/mm: Fix RESERVE_BRK() for older binutils") > added the "NOLOAD" attribute to the .brk section as a "failsafe" > measure. > > Unfortunately this leads to the linker no longer covering the .brk > section in a program header, resulting in the kernel loader not knowing > that the memory for the .brk section must be reserved. > > This has led to crashes when loading the kernel as PV dom0 under Xen, > but other scenarios could be hit by the same problem (e.g. in case an > uncompressed kernel is used and the initrd is placed directly behind > it). > > So drop the "NOLOAD" attribute. This has been verified to correctly > cover the .brk section by a program header of the resulting ELF file. > > Fixes: e32683c6f7d2 ("x86/mm: Fix RESERVE_BRK() for older binutils") > Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 81aba718ecd5..9487ce8c13ee 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -385,7 +385,7 @@ SECTIONS __end_of_kernel_reserve = .; . = ALIGN(PAGE_SIZE); - .brk (NOLOAD) : AT(ADDR(.brk) - LOAD_OFFSET) { + .brk : AT(ADDR(.brk) - LOAD_OFFSET) { __brk_base = .; . += 64 * 1024; /* 64k alignment slop space */ *(.bss..brk) /* areas brk users have reserved */
Commit e32683c6f7d2 ("x86/mm: Fix RESERVE_BRK() for older binutils") added the "NOLOAD" attribute to the .brk section as a "failsafe" measure. Unfortunately this leads to the linker no longer covering the .brk section in a program header, resulting in the kernel loader not knowing that the memory for the .brk section must be reserved. This has led to crashes when loading the kernel as PV dom0 under Xen, but other scenarios could be hit by the same problem (e.g. in case an uncompressed kernel is used and the initrd is placed directly behind it). So drop the "NOLOAD" attribute. This has been verified to correctly cover the .brk section by a program header of the resulting ELF file. Fixes: e32683c6f7d2 ("x86/mm: Fix RESERVE_BRK() for older binutils") Signed-off-by: Juergen Gross <jgross@suse.com> --- V2: - new patch --- arch/x86/kernel/vmlinux.lds.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)