diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/mm.h | 22 | ||||
| -rw-r--r-- | include/linux/phy.h | 4 |
2 files changed, 15 insertions, 11 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index f092ce3530bb..a3f97c551ad8 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -4263,14 +4263,13 @@ int arch_lock_shadow_stack_status(struct task_struct *t, unsigned long status); * since this value becomes part of PP_SIGNATURE; meaning we can just use the * space between the PP_SIGNATURE value (without POISON_POINTER_DELTA), and the * lowest bits of POISON_POINTER_DELTA. On arches where POISON_POINTER_DELTA is - * 0, we make sure that we leave the two topmost bits empty, as that guarantees - * we won't mistake a valid kernel pointer for a value we set, regardless of the - * VMSPLIT setting. + * 0, we use the lowest bit of PAGE_OFFSET as the boundary if that value is + * known at compile-time. * - * Altogether, this means that the number of bits available is constrained by - * the size of an unsigned long (at the upper end, subtracting two bits per the - * above), and the definition of PP_SIGNATURE (with or without - * POISON_POINTER_DELTA). + * If the value of PAGE_OFFSET is not known at compile time, or if it is too + * small to leave at least 8 bits available above PP_SIGNATURE, we define the + * number of bits to be 0, which turns off the DMA index tracking altogether + * (see page_pool_register_dma_index()). */ #define PP_DMA_INDEX_SHIFT (1 + __fls(PP_SIGNATURE - POISON_POINTER_DELTA)) #if POISON_POINTER_DELTA > 0 @@ -4279,8 +4278,13 @@ int arch_lock_shadow_stack_status(struct task_struct *t, unsigned long status); */ #define PP_DMA_INDEX_BITS MIN(32, __ffs(POISON_POINTER_DELTA) - PP_DMA_INDEX_SHIFT) #else -/* Always leave out the topmost two; see above. */ -#define PP_DMA_INDEX_BITS MIN(32, BITS_PER_LONG - PP_DMA_INDEX_SHIFT - 2) +/* Use the lowest bit of PAGE_OFFSET if there's at least 8 bits available; see above */ +#define PP_DMA_INDEX_MIN_OFFSET (1 << (PP_DMA_INDEX_SHIFT + 8)) +#define PP_DMA_INDEX_BITS ((__builtin_constant_p(PAGE_OFFSET) && \ + PAGE_OFFSET >= PP_DMA_INDEX_MIN_OFFSET && \ + !(PAGE_OFFSET & (PP_DMA_INDEX_MIN_OFFSET - 1))) ? \ + MIN(32, __ffs(PAGE_OFFSET) - PP_DMA_INDEX_SHIFT) : 0) + #endif #define PP_DMA_INDEX_MASK GENMASK(PP_DMA_INDEX_BITS + PP_DMA_INDEX_SHIFT - 1, \ diff --git a/include/linux/phy.h b/include/linux/phy.h index 7a54a8b4d277..3c7634482356 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -297,7 +297,7 @@ static inline const char *phy_modes(phy_interface_t interface) * * Description: maps RGMII supported link speeds into the clock rates. * This can also be used for MII, GMII, and RMII interface modes as the - * clock rates are indentical, but the caller must be aware that errors + * clock rates are identical, but the caller must be aware that errors * for unsupported clock rates will not be signalled. * * Returns: clock rate or negative errno @@ -519,7 +519,7 @@ enum phy_state { * struct phy_c45_device_ids - 802.3-c45 Device Identifiers * @devices_in_package: IEEE 802.3 devices in package register value. * @mmds_present: bit vector of MMDs present. - * @device_ids: The device identifer for each present device. + * @device_ids: The device identifier for each present device. */ struct phy_c45_device_ids { u32 devices_in_package; |