Home
last modified time | relevance | path

Searched hist:"598 f5630" (Results 1 – 1 of 1) sorted by relevance

/openbmc/linux/arch/um/kernel/
H A Duml.lds.S598f5630 Thu Mar 05 12:39:39 CST 2020 David Gow <davidgow@google.com> um: Fix overlapping ELF segments when statically linked

When statically linked, the .text section in UML kernels is not page
aligned, causing it to share a page with the executable headers. As
.text and the executable headers have different permissions, this causes
the kernel to wish to map the same page twice (once as headers with r--
permissions, once as .text with r-x permissions), causing a segfault,
and a nasty message printed to the host kernel's dmesg:

"Uhuuh, elf segment at 0000000060000000 requested but the memory is
mapped already"

By aligning the .text to a page boundary (as in the dynamically linked
version in dyn.lds.S), there is no such overlap, and the kernel runs
correctly.

Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
598f5630 Thu Mar 05 12:39:39 CST 2020 David Gow <davidgow@google.com> um: Fix overlapping ELF segments when statically linked

When statically linked, the .text section in UML kernels is not page
aligned, causing it to share a page with the executable headers. As
.text and the executable headers have different permissions, this causes
the kernel to wish to map the same page twice (once as headers with r--
permissions, once as .text with r-x permissions), causing a segfault,
and a nasty message printed to the host kernel's dmesg:

"Uhuuh, elf segment at 0000000060000000 requested but the memory is
mapped already"

By aligning the .text to a page boundary (as in the dynamically linked
version in dyn.lds.S), there is no such overlap, and the kernel runs
correctly.

Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>