Changes since v1: ---------------- - v1 was sent out as a single patch which can be seen here: http://lists.infradead.org/pipermail/kexec/2019-February/022411.html
- v2 breaks the single patch into two independent patches: [PATCH 1/2] appends 'PTRS_PER_PGD' to vmcoreinfo for arm64 arch, whereas [PATCH 2/2] appends 'MAX_PHYSMEM_BITS' to vmcoreinfo in core kernel code (all archs) This patchset primarily fixes the regression reported in user-space utilities like 'makedumpfile' and 'crash-utility' on arm64 architecture with the availability of 52-bit address space feature in underlying kernel. These regressions have been reported both on CPUs which don't support ARMv8.2 extensions (i.e. LVA, LPA) and are running newer kernels and also on prototype platforms (like ARMv8 FVP simulator model) which support ARMv8.2 extensions and are running newer kernels. The reason for these regressions is that right now user-space tools have no direct access to these values (since these are not exported from the kernel) and hence need to rely on a best-guess method of determining value of 'PTRS_PER_PGD' and 'MAX_PHYSMEM_BITS' supported by underlying kernel. Exporting these values via vmcoreinfo will help user-land in such cases. In addition, as per suggestion from makedumpfile maintainer (Kazu) during v1 review, it makes more sense to append 'MAX_PHYSMEM_BITS' to vmcoreinfo in the core code itself rather than in arm64 arch-specific code, so that the user-space code for other archs can also benefit from this addition to the vmcoreinfo and use it as a standard way of determining 'SECTIONS_SHIFT' value in user-land. Cc: Mark Rutland <[email protected]> Cc: James Morse <[email protected]> Cc: Will Deacon <[email protected]> Cc: Boris Petkov <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Benjamin Herrenschmidt <[email protected]> Cc: Dave Anderson <[email protected]> Cc: Kazuhito Hagio <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Bhupesh Sharma (2): arm64, vmcoreinfo : Append 'PTRS_PER_PGD' to vmcoreinfo crash_core, vmcoreinfo: Append 'MAX_PHYSMEM_BITS' to vmcoreinfo arch/arm64/kernel/crash_core.c | 1 + kernel/crash_core.c | 1 + 2 files changed, 2 insertions(+) -- 2.7.4
