Re: [PATCH v6 0/3] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory.
On Tue, Sep 11, 2018 at 09:28:44AM +0200, Rafael J. Wysocki wrote: >On Tue, Sep 11, 2018 at 3:13 AM Chao Fan wrote: >> >> sorry, the cover letter forwand to rafael. > >Thanks, but the relevant information still needs to go to the >changelog of the patch adding the extra ACPI tables parsing code. >Your cover letter will not be there in the git log. > >I also would suggest to CC the entire series to linux-acpi along with >the cover letter. OK, I will add more in next version. Thanks, Chao Fan > >Thanks, >Rafael > >
Re: [PATCH v6 0/3] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory.
On Tue, Sep 11, 2018 at 09:28:44AM +0200, Rafael J. Wysocki wrote: >On Tue, Sep 11, 2018 at 3:13 AM Chao Fan wrote: >> >> sorry, the cover letter forwand to rafael. > >Thanks, but the relevant information still needs to go to the >changelog of the patch adding the extra ACPI tables parsing code. >Your cover letter will not be there in the git log. > >I also would suggest to CC the entire series to linux-acpi along with >the cover letter. OK, I will add more in next version. Thanks, Chao Fan > >Thanks, >Rafael > >
Re: [PATCH v6 0/3] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory.
On Tue, Sep 11, 2018 at 3:13 AM Chao Fan wrote: > > sorry, the cover letter forwand to rafael. Thanks, but the relevant information still needs to go to the changelog of the patch adding the extra ACPI tables parsing code. Your cover letter will not be there in the git log. I also would suggest to CC the entire series to linux-acpi along with the cover letter. Thanks, Rafael
Re: [PATCH v6 0/3] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory.
On Tue, Sep 11, 2018 at 3:13 AM Chao Fan wrote: > > sorry, the cover letter forwand to rafael. Thanks, but the relevant information still needs to go to the changelog of the patch adding the extra ACPI tables parsing code. Your cover letter will not be there in the git log. I also would suggest to CC the entire series to linux-acpi along with the cover letter. Thanks, Rafael
Re: [PATCH v6 0/3] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory.
sorry, the cover letter forwand to rafael. Thanks, Chao Fan On Mon, Sep 10, 2018 at 08:40:12PM +0800, Chao Fan wrote: >***Background: >People reported that kaslr may randomly chooses some positions >which are located in movable memory regions. This will break memory >hotplug feature and make the movable memory chosen by KASLR can't be >removed. > >***Solutions: >There should be a method to limit kaslr to choosing immovable memory >regions, so there are 2 solutions: >1) Add a kernel parameter to specify the memory regions. >2) Get the information of memory hot-remove, then kaslr will know the > right regions. >In method 2, information about memory hot-remove is in ACPI >tables, which will be parsed after start_kernel(), kaslr can't get >the information. >In method 1, users should know the regions address and specify in >kernel parameter. > >In the earliest time, I tried to dig ACPI tabls to solve this problem. >But I didn't splite the code in 'compressed/' and ACPI code, so the patch >is hard to follow so refused by community. >Somebody suggest to add a kernel parameter to specify the >immovable memory so that limit kaslr in these regions. Then I make >a new patchset. After several versions, Ingo gave a suggestion: >https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1634024.html >Follow Ingo's suggestion, imitate the ACPI code to parse the acpi >tables, so that the kaslr can get necessary memory information in >ACPI tables. >I think ACPI code is an independent part, so copy the codes >and functions to 'compressed/' directory, so that kaslr won't >influence the initialization of ACPI. > >PATCH 1/3 Add acpitb.c to provide functions to parse ACPI code. >PATCH 2/3 If CONFIG_MEMORY_HOTREMOVE enabled, walk all nodes and > store the information of immovable memory regions. >PATCH 3/3 According to the immovable memory regions, filter the > immovable regions which KASLR can choose. > >***Test results: > - I did a very simple test, and it can get the memory information in > bios and efi KVM guest machine, and put it by early printk. But no > more tests, so it's with RFC tag. > >v1->v2: > - Simplify some code. >Follow Baoquan He's suggestion: > - Reuse the head file of acpi code. > >v2->v3: > - Test in more conditions, so remove the 'RFC' tag. > - Change some comments. > >v3->v4: >Follow Thomas Gleixner's suggetsion: > - Put the whole efi related function into #define CONFIG_EFI and return > false in the other stub. > - Simplify two functions in head file. > >v4->v5: >Follow Dou Liyang's suggestion: > - Add more comments about some functions based on kernel code. > - Change some typo in comments. > - Clean useless variable. > - Add check for the boundary of array. > - Add check for 'movable_node' parameter > >v5->v6: >Follow Baoquan He's suggestion: > - Change some log. > - Add the check for acpi_rsdp > - Change some code logical to make code clear > >Any comments will be welcome. > > >Chao Fan (3): > x86/boot: Add acpitb.c to parse acpi tables > x86/boot/KASLR: Walk srat tables to filter immovable memory > x86/boot/KASLR: Limit kaslr to choosing the immovable memory > > arch/x86/boot/compressed/Makefile | 4 + > arch/x86/boot/compressed/acpitb.c | 382 ++ > arch/x86/boot/compressed/kaslr.c | 76 +- > arch/x86/boot/compressed/misc.h | 8 + > 4 files changed, 459 insertions(+), 11 deletions(-) > create mode 100644 arch/x86/boot/compressed/acpitb.c > >-- >2.17.1 >
Re: [PATCH v6 0/3] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory.
sorry, the cover letter forwand to rafael. Thanks, Chao Fan On Mon, Sep 10, 2018 at 08:40:12PM +0800, Chao Fan wrote: >***Background: >People reported that kaslr may randomly chooses some positions >which are located in movable memory regions. This will break memory >hotplug feature and make the movable memory chosen by KASLR can't be >removed. > >***Solutions: >There should be a method to limit kaslr to choosing immovable memory >regions, so there are 2 solutions: >1) Add a kernel parameter to specify the memory regions. >2) Get the information of memory hot-remove, then kaslr will know the > right regions. >In method 2, information about memory hot-remove is in ACPI >tables, which will be parsed after start_kernel(), kaslr can't get >the information. >In method 1, users should know the regions address and specify in >kernel parameter. > >In the earliest time, I tried to dig ACPI tabls to solve this problem. >But I didn't splite the code in 'compressed/' and ACPI code, so the patch >is hard to follow so refused by community. >Somebody suggest to add a kernel parameter to specify the >immovable memory so that limit kaslr in these regions. Then I make >a new patchset. After several versions, Ingo gave a suggestion: >https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1634024.html >Follow Ingo's suggestion, imitate the ACPI code to parse the acpi >tables, so that the kaslr can get necessary memory information in >ACPI tables. >I think ACPI code is an independent part, so copy the codes >and functions to 'compressed/' directory, so that kaslr won't >influence the initialization of ACPI. > >PATCH 1/3 Add acpitb.c to provide functions to parse ACPI code. >PATCH 2/3 If CONFIG_MEMORY_HOTREMOVE enabled, walk all nodes and > store the information of immovable memory regions. >PATCH 3/3 According to the immovable memory regions, filter the > immovable regions which KASLR can choose. > >***Test results: > - I did a very simple test, and it can get the memory information in > bios and efi KVM guest machine, and put it by early printk. But no > more tests, so it's with RFC tag. > >v1->v2: > - Simplify some code. >Follow Baoquan He's suggestion: > - Reuse the head file of acpi code. > >v2->v3: > - Test in more conditions, so remove the 'RFC' tag. > - Change some comments. > >v3->v4: >Follow Thomas Gleixner's suggetsion: > - Put the whole efi related function into #define CONFIG_EFI and return > false in the other stub. > - Simplify two functions in head file. > >v4->v5: >Follow Dou Liyang's suggestion: > - Add more comments about some functions based on kernel code. > - Change some typo in comments. > - Clean useless variable. > - Add check for the boundary of array. > - Add check for 'movable_node' parameter > >v5->v6: >Follow Baoquan He's suggestion: > - Change some log. > - Add the check for acpi_rsdp > - Change some code logical to make code clear > >Any comments will be welcome. > > >Chao Fan (3): > x86/boot: Add acpitb.c to parse acpi tables > x86/boot/KASLR: Walk srat tables to filter immovable memory > x86/boot/KASLR: Limit kaslr to choosing the immovable memory > > arch/x86/boot/compressed/Makefile | 4 + > arch/x86/boot/compressed/acpitb.c | 382 ++ > arch/x86/boot/compressed/kaslr.c | 76 +- > arch/x86/boot/compressed/misc.h | 8 + > 4 files changed, 459 insertions(+), 11 deletions(-) > create mode 100644 arch/x86/boot/compressed/acpitb.c > >-- >2.17.1 >
[PATCH v6 0/3] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory.
***Background: People reported that kaslr may randomly chooses some positions which are located in movable memory regions. This will break memory hotplug feature and make the movable memory chosen by KASLR can't be removed. ***Solutions: There should be a method to limit kaslr to choosing immovable memory regions, so there are 2 solutions: 1) Add a kernel parameter to specify the memory regions. 2) Get the information of memory hot-remove, then kaslr will know the right regions. In method 2, information about memory hot-remove is in ACPI tables, which will be parsed after start_kernel(), kaslr can't get the information. In method 1, users should know the regions address and specify in kernel parameter. In the earliest time, I tried to dig ACPI tabls to solve this problem. But I didn't splite the code in 'compressed/' and ACPI code, so the patch is hard to follow so refused by community. Somebody suggest to add a kernel parameter to specify the immovable memory so that limit kaslr in these regions. Then I make a new patchset. After several versions, Ingo gave a suggestion: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1634024.html Follow Ingo's suggestion, imitate the ACPI code to parse the acpi tables, so that the kaslr can get necessary memory information in ACPI tables. I think ACPI code is an independent part, so copy the codes and functions to 'compressed/' directory, so that kaslr won't influence the initialization of ACPI. PATCH 1/3 Add acpitb.c to provide functions to parse ACPI code. PATCH 2/3 If CONFIG_MEMORY_HOTREMOVE enabled, walk all nodes and store the information of immovable memory regions. PATCH 3/3 According to the immovable memory regions, filter the immovable regions which KASLR can choose. ***Test results: - I did a very simple test, and it can get the memory information in bios and efi KVM guest machine, and put it by early printk. But no more tests, so it's with RFC tag. v1->v2: - Simplify some code. Follow Baoquan He's suggestion: - Reuse the head file of acpi code. v2->v3: - Test in more conditions, so remove the 'RFC' tag. - Change some comments. v3->v4: Follow Thomas Gleixner's suggetsion: - Put the whole efi related function into #define CONFIG_EFI and return false in the other stub. - Simplify two functions in head file. v4->v5: Follow Dou Liyang's suggestion: - Add more comments about some functions based on kernel code. - Change some typo in comments. - Clean useless variable. - Add check for the boundary of array. - Add check for 'movable_node' parameter v5->v6: Follow Baoquan He's suggestion: - Change some log. - Add the check for acpi_rsdp - Change some code logical to make code clear Any comments will be welcome. Chao Fan (3): x86/boot: Add acpitb.c to parse acpi tables x86/boot/KASLR: Walk srat tables to filter immovable memory x86/boot/KASLR: Limit kaslr to choosing the immovable memory arch/x86/boot/compressed/Makefile | 4 + arch/x86/boot/compressed/acpitb.c | 382 ++ arch/x86/boot/compressed/kaslr.c | 76 +- arch/x86/boot/compressed/misc.h | 8 + 4 files changed, 459 insertions(+), 11 deletions(-) create mode 100644 arch/x86/boot/compressed/acpitb.c -- 2.17.1
[PATCH v6 0/3] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory.
***Background: People reported that kaslr may randomly chooses some positions which are located in movable memory regions. This will break memory hotplug feature and make the movable memory chosen by KASLR can't be removed. ***Solutions: There should be a method to limit kaslr to choosing immovable memory regions, so there are 2 solutions: 1) Add a kernel parameter to specify the memory regions. 2) Get the information of memory hot-remove, then kaslr will know the right regions. In method 2, information about memory hot-remove is in ACPI tables, which will be parsed after start_kernel(), kaslr can't get the information. In method 1, users should know the regions address and specify in kernel parameter. In the earliest time, I tried to dig ACPI tabls to solve this problem. But I didn't splite the code in 'compressed/' and ACPI code, so the patch is hard to follow so refused by community. Somebody suggest to add a kernel parameter to specify the immovable memory so that limit kaslr in these regions. Then I make a new patchset. After several versions, Ingo gave a suggestion: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1634024.html Follow Ingo's suggestion, imitate the ACPI code to parse the acpi tables, so that the kaslr can get necessary memory information in ACPI tables. I think ACPI code is an independent part, so copy the codes and functions to 'compressed/' directory, so that kaslr won't influence the initialization of ACPI. PATCH 1/3 Add acpitb.c to provide functions to parse ACPI code. PATCH 2/3 If CONFIG_MEMORY_HOTREMOVE enabled, walk all nodes and store the information of immovable memory regions. PATCH 3/3 According to the immovable memory regions, filter the immovable regions which KASLR can choose. ***Test results: - I did a very simple test, and it can get the memory information in bios and efi KVM guest machine, and put it by early printk. But no more tests, so it's with RFC tag. v1->v2: - Simplify some code. Follow Baoquan He's suggestion: - Reuse the head file of acpi code. v2->v3: - Test in more conditions, so remove the 'RFC' tag. - Change some comments. v3->v4: Follow Thomas Gleixner's suggetsion: - Put the whole efi related function into #define CONFIG_EFI and return false in the other stub. - Simplify two functions in head file. v4->v5: Follow Dou Liyang's suggestion: - Add more comments about some functions based on kernel code. - Change some typo in comments. - Clean useless variable. - Add check for the boundary of array. - Add check for 'movable_node' parameter v5->v6: Follow Baoquan He's suggestion: - Change some log. - Add the check for acpi_rsdp - Change some code logical to make code clear Any comments will be welcome. Chao Fan (3): x86/boot: Add acpitb.c to parse acpi tables x86/boot/KASLR: Walk srat tables to filter immovable memory x86/boot/KASLR: Limit kaslr to choosing the immovable memory arch/x86/boot/compressed/Makefile | 4 + arch/x86/boot/compressed/acpitb.c | 382 ++ arch/x86/boot/compressed/kaslr.c | 76 +- arch/x86/boot/compressed/misc.h | 8 + 4 files changed, 459 insertions(+), 11 deletions(-) create mode 100644 arch/x86/boot/compressed/acpitb.c -- 2.17.1
