History log of /src/sys/arch/amd64/stand/prekern/locore.S |
Revision | | Date | Author | Comments |
1.11 |
| 19-Mar-2019 |
maxv | Fix/remove some half-baked stuff I left in the prekern:
- Page-align the idt store, to be extra sure. - Remove unneeded prototypes. - Drop the TSS, we don't care and aren't even using it. - Initialize %ss with a default value. - Fix three exception handlers, no need to push an error code.
No actual impact, because these things are used only when returning from exceptions received in the prekern; these exceptions are not supposed to be ever received, never are, and if they were we wouldn't return anyway.
|
1.10 |
| 09-Mar-2019 |
maxv | Start replacing the x86 PTE bits.
|
1.9 |
| 07-Mar-2019 |
maxv | Drop PG_RO, PG_KR and PG_PROT, they are useless and create confusion.
|
1.8 |
| 25-May-2018 |
maxv | branches: 1.8.2; Hide a bunch of local symbols.
|
1.7 |
| 22-Dec-2017 |
maxv | branches: 1.7.2; Sync comments with reality.
|
1.6 |
| 26-Nov-2017 |
maxv | branches: 1.6.2; Add rdrand.
|
1.5 |
| 14-Nov-2017 |
maxv | Remove XXX: set FRAMESIZE to the kernel value. Verily I don't understand why we are doing that in the non-kaslr kernels, but let's just reproduce the behavior.
jump_kernel is changed to use callq, so that the stack alignment is preserved.
|
1.4 |
| 10-Nov-2017 |
maxv | Add cpuid and rdseed.
|
1.3 |
| 29-Oct-2017 |
maxv | Randomize the kernel segments independently. That is to say, put text, rodata and data at different addresses (and in a random order).
To achieve that, the mapping order in the prekern is changed. Until now, we were creating the kernel map the following way: -> choose a random VA -> map [kernpa_start; kernpa_end[ at this VA -> parse the ELF structures from there -> determine where exactly the kernel segments are located -> relocate etc Now, we are doing: -> create a read-only view of [kernpa_start; kernpa_end[ -> from this view, compute the size of the "head" region -> choose a random VA in the HEAD window, and map the head there -> for each region in (text, rodata, data, boot) -> compute the size of the region from the RO view -> choose a random VA in the KASLR window -> map the region there -> relocate etc
Each time we map a region, we initialize its bootspace fields right away.
The "head" region must be put before the other regions in memory, because the kernel uses (headva + sh_offset) to get the addresses of the symbols, and the offset is unsigned.
Given that the head does not have an mcmodel constraint, its location is randomized in a window located below the KASLR window.
The rest of the regions being in the same window, we need to detect collisions.
Note that the module map is embedded in the "boot" region, and that therefore its location is randomized too.
|
1.2 |
| 11-Oct-2017 |
maxv | Remove this #if, these options belong to the kernel and not the prekern. No real change since eblob is always here. And I was apparently drunk when writing some comments.
|
1.1 |
| 10-Oct-2017 |
maxv | Add the amd64 prekern. It is a kernel relocator used for Kernel ASLR (see tech-kern@). It works, but is not yet linked to the build system, because I can't build a distribution right now.
|
1.6.2.2 |
| 03-Dec-2017 |
jdolecek | update from HEAD
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1.6.2.1 |
| 26-Nov-2017 |
jdolecek | file locore.S was added on branch tls-maxphys on 2017-12-03 11:35:48 +0000
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1.7.2.1 |
| 25-Jun-2018 |
pgoyette | Sync with HEAD
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1.8.2.1 |
| 10-Jun-2019 |
christos | Sync with HEAD
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