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| author | Krzysztof Mazur <krzysiek@podlesie.net> | 2015-11-06 14:18:36 +0100 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2016-01-05 16:23:33 +0100 |
| commit | 590861b7ab103e459aae9ddbc06ce59302a0b5ad (patch) | |
| tree | 1a107b532e1bc779c0e3d4507e2bb331cc234cc5 | |
| parent | 2c131230744f95abdbecffbf19de6bfa8a889253 (diff) | |
| download | lwn-590861b7ab103e459aae9ddbc06ce59302a0b5ad.tar.gz lwn-590861b7ab103e459aae9ddbc06ce59302a0b5ad.zip | |
x86/setup: Fix low identity map for >= 2GB kernel range
commit 68accac392d859d24adcf1be3a90e41f978bd54c upstream.
The commit f5f3497cad8c extended the low identity mapping. However, if
the kernel uses more than 2 GB (VMSPLIT_2G_OPT or VMSPLIT_1G memory
split), the normal memory mapping is overwritten by the low identity
mapping causing a crash. To avoid overwritting, limit the low identity
map to cover only memory before kernel range (PAGE_OFFSET).
Fixes: f5f3497cad8c "x86/setup: Extend low identity map to cover whole kernel range
Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: http://lkml.kernel.org/r/1446815916-22105-1-git-send-email-krzysiek@podlesie.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| -rw-r--r-- | arch/x86/kernel/setup.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 29ecd5e00605..3ebbd1fdc0a8 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1161,7 +1161,7 @@ void __init setup_arch(char **cmdline_p) */ clone_pgd_range(initial_page_table, swapper_pg_dir + KERNEL_PGD_BOUNDARY, - KERNEL_PGD_PTRS); + min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY)); #endif tboot_probe(); |