Revision f6242cac10427c546271050b31c891a078e490cd authored by Marc Zyngier on 24 February 2015, 16:30:21 UTC, committed by Catalin Marinas on 26 February 2015, 18:34:27 UTC
Patch 2f896d586610 ("arm64: use fixmap for text patching") changed the way we patch the kernel text, using a fixmap when the kernel or modules are flagged as read only. Unfortunately, a flaw in the logic makes it fall over when patching modules without CONFIG_DEBUG_SET_MODULE_RONX enabled: [...] [ 32.032636] Call trace: [ 32.032716] [<fffffe00003da0dc>] __copy_to_user+0x2c/0x60 [ 32.032837] [<fffffe0000099f08>] __aarch64_insn_write+0x94/0xf8 [ 32.033027] [<fffffe000009a0a0>] aarch64_insn_patch_text_nosync+0x18/0x58 [ 32.033200] [<fffffe000009c3ec>] ftrace_modify_code+0x58/0x84 [ 32.033363] [<fffffe000009c4e4>] ftrace_make_nop+0x3c/0x58 [ 32.033532] [<fffffe0000164420>] ftrace_process_locs+0x3d0/0x5c8 [ 32.033709] [<fffffe00001661cc>] ftrace_module_init+0x28/0x34 [ 32.033882] [<fffffe0000135148>] load_module+0xbb8/0xfc4 [ 32.034044] [<fffffe0000135714>] SyS_finit_module+0x94/0xc4 [...] This is triggered by the use of virt_to_page() on a module address, which ends to pointing to Nowhereland if you're lucky, or corrupt your precious data if not. This patch fixes the logic by mimicking what is done on arm: - If we're patching a module and CONFIG_DEBUG_SET_MODULE_RONX is set, use vmalloc_to_page(). - If we're patching the kernel and CONFIG_DEBUG_RODATA is set, use virt_to_page(). - Otherwise, use the provided address, as we can write to it directly. Tested on 4.0-rc1 as a KVM guest. Reported-by: Richard W.M. Jones <rjones@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Laura Abbott <lauraa@codeaurora.org> Tested-by: Richard W.M. Jones <rjones@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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File | Mode | Size |
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Documentation | ||
arch | ||
block | ||
crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.gitignore | -rw-r--r-- | 1.2 KB |
.mailmap | -rw-r--r-- | 4.9 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 94.0 KB |
Kbuild | -rw-r--r-- | 2.1 KB |
Kconfig | -rw-r--r-- | 252 bytes |
MAINTAINERS | -rw-r--r-- | 298.0 KB |
Makefile | -rw-r--r-- | 53.3 KB |
README | -rw-r--r-- | 18.3 KB |
REPORTING-BUGS | -rw-r--r-- | 7.3 KB |
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