Messages in this thread | | | From | Andy Lutomirski <> | Subject | [PATCH 0/4] x86,mm: vdso fixes for an OOPS and /proc/PID/maps | Date | Mon, 19 May 2014 15:58:30 -0700 |
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[This applies to tip/x86/vdso. Patch 1/4 is a resend.]
This fixes an OOPS on systems without an HPET and incomplete information in /proc/PID/maps.
The latter is done by adding a new vm_ops callback to replace arch_vma_name, which is inflexible and awkward to use correctly.
With this series applied, calling mremap on the vdso results in sensible output in /proc/PID/maps and the vvar area shows up correctly. I don't want to guarantee that mremap on the vdso will do anything sensible right now, but that's unchanged from before. In fact, I suspect that mremapping the vdso on 32-bit tasks is rather broken right now due to sigreturn.
In current kernels, mremapping the vdso blows away the name: badc0de0000-badc0de2000 r-xp 00000000 00:00 0
Now it doesn't: badc0de0000-badc0de1000 r-xp 00000000 00:00 0 [vdso]
As a followup, it might pay to replace install_special_mapping with a new install_vdso_mapping function that hardcodes the "[vdso]" name, to separately fix all the other arch_vma_name users (maybe just ARM?) and then kill arch_vma_name completely.
NB: This touches core mm code. I'd appreciate some review by the mm folks.
Andy Lutomirski (4): x86,vdso: Fix an OOPS accessing the hpet mapping w/o an hpet mm,fs: Add vm_ops->name as an alternative to arch_vma_name x86,mm: Improve _install_special_mapping and fix x86 vdso naming x86,mm: Replace arch_vma_name with vm_ops->name for vsyscalls
arch/x86/include/asm/vdso.h | 6 ++- arch/x86/mm/init_64.c | 20 +++++----- arch/x86/vdso/vdso2c.h | 5 ++- arch/x86/vdso/vdso32-setup.c | 7 ---- arch/x86/vdso/vma.c | 26 ++++++++----- fs/binfmt_elf.c | 8 ++++ fs/proc/task_mmu.c | 6 +++ include/linux/mm.h | 10 ++++- include/linux/mm_types.h | 6 +++ mm/mmap.c | 89 +++++++++++++++++++++++++++++--------------- 10 files changed, 124 insertions(+), 59 deletions(-)
-- 1.9.0
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