| Message ID | 20230808130709.1502614-1-alexghiti@rivosinc.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | d566bea4a638ff0ae824df804bc08818bace41a5 |
| Headers | show |
| Series | [-fixes] riscv: Do not allow vmap pud mappings for 3-level page table | expand |
| Context | Check | Description |
|---|---|---|
| conchuod/cover_letter | success | Single patches do not need cover letters |
| conchuod/tree_selection | success | Guessed tree name to be fixes at HEAD d2402048bc8a |
| conchuod/fixes_present | success | Fixes tag present in non-next series |
| conchuod/maintainers_pattern | success | MAINTAINERS pattern errors before the patch: 4 and now 4 |
| conchuod/verify_signedoff | success | Signed-off-by tag matches author and committer |
| conchuod/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| conchuod/build_rv64_clang_allmodconfig | success | Errors and warnings before: 2683 this patch: 2683 |
| conchuod/module_param | success | Was 0 now: 0 |
| conchuod/build_rv64_gcc_allmodconfig | success | Errors and warnings before: 15138 this patch: 15138 |
| conchuod/build_rv32_defconfig | success | Build OK |
| conchuod/dtb_warn_rv64 | success | Errors and warnings before: 12 this patch: 12 |
| conchuod/header_inline | success | No static functions without inline keyword in header files |
| conchuod/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 15 lines checked |
| conchuod/build_rv64_nommu_k210_defconfig | success | Build OK |
| conchuod/verify_fixes | success | Fixes tag looks correct |
| conchuod/build_rv64_nommu_virt_defconfig | success | Build OK |
Hello: This patch was applied to riscv/linux.git (fixes) by Palmer Dabbelt <palmer@rivosinc.com>: On Tue, 8 Aug 2023 15:07:09 +0200 you wrote: > The vmalloc_fault() path was removed and to avoid syncing the vmalloc PGD > mappings, they are now preallocated. But if the kernel can use a PUD > mapping (which in sv39 is actually a PGD mapping) for large vmalloc > allocation, it will free the current unused preallocated PGD mapping and > install a new leaf one. Since there is no sync anymore, some page tables > lack this new mapping and that triggers a panic. > > [...] Here is the summary with links: - [-fixes] riscv: Do not allow vmap pud mappings for 3-level page table https://git.kernel.org/riscv/c/d566bea4a638 You are awesome, thank you!
diff --git a/arch/riscv/include/asm/vmalloc.h b/arch/riscv/include/asm/vmalloc.h index 58d3e447f191..924d01b56c9a 100644 --- a/arch/riscv/include/asm/vmalloc.h +++ b/arch/riscv/include/asm/vmalloc.h @@ -3,12 +3,14 @@ #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP +extern bool pgtable_l4_enabled, pgtable_l5_enabled; + #define IOREMAP_MAX_ORDER (PUD_SHIFT) #define arch_vmap_pud_supported arch_vmap_pud_supported static inline bool arch_vmap_pud_supported(pgprot_t prot) { - return true; + return pgtable_l4_enabled || pgtable_l5_enabled; } #define arch_vmap_pmd_supported arch_vmap_pmd_supported
The vmalloc_fault() path was removed and to avoid syncing the vmalloc PGD mappings, they are now preallocated. But if the kernel can use a PUD mapping (which in sv39 is actually a PGD mapping) for large vmalloc allocation, it will free the current unused preallocated PGD mapping and install a new leaf one. Since there is no sync anymore, some page tables lack this new mapping and that triggers a panic. So only allow PUD mappings for sv48 and sv57. Fixes: 7d3332be011e ("riscv: mm: Pre-allocate PGD entries for vmalloc/modules area") Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> --- arch/riscv/include/asm/vmalloc.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)