From: Helge Deller deller@gmx.de
commit 56675f8b9f9b15b024b8e3145fa289b004916ab7 upstream.
The changes from commit 32832a407a71 ("io_uring: Fix io_uring mmap() by using architecture-provided get_unmapped_area()") to the parisc implementation of get_unmapped_area() broke glibc's locale-gen executable when running on parisc.
This patch reverts those architecture-specific changes, and instead adjusts in io_uring_mmu_get_unmapped_area() the pgoff offset which is then given to parisc's get_unmapped_area() function. This is much cleaner than the previous approach, and we still will get a coherent addresss.
This patch has no effect on other architectures (SHM_COLOUR is only defined on parisc), and the liburing testcase stil passes on parisc.
Cc: stable@vger.kernel.org # 6.4 Signed-off-by: Helge Deller deller@gmx.de Reported-by: Christoph Biedl linux-kernel.bfrz@manchmal.in-ulm.de Fixes: 32832a407a71 ("io_uring: Fix io_uring mmap() by using architecture-provided get_unmapped_area()") Fixes: d808459b2e31 ("io_uring: Adjust mapping wrt architecture aliasing requirements") Link: https://lore.kernel.org/r/ZNEyGV0jyI8kOOfz@p100 Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/parisc/kernel/sys_parisc.c | 15 +++++---------- io_uring/io_uring.c | 3 +++ 2 files changed, 8 insertions(+), 10 deletions(-)
--- a/arch/parisc/kernel/sys_parisc.c +++ b/arch/parisc/kernel/sys_parisc.c @@ -26,17 +26,12 @@ #include <linux/compat.h>
/* - * Construct an artificial page offset for the mapping based on the virtual + * Construct an artificial page offset for the mapping based on the physical * address of the kernel file mapping variable. - * If filp is zero the calculated pgoff value aliases the memory of the given - * address. This is useful for io_uring where the mapping shall alias a kernel - * address and a userspace adress where both the kernel and the userspace - * access the same memory region. */ -#define GET_FILP_PGOFF(filp, addr) \ - ((filp ? (((unsigned long) filp->f_mapping) >> 8) \ - & ((SHM_COLOUR-1) >> PAGE_SHIFT) : 0UL) \ - + (addr >> PAGE_SHIFT)) +#define GET_FILP_PGOFF(filp) \ + (filp ? (((unsigned long) filp->f_mapping) >> 8) \ + & ((SHM_COLOUR-1) >> PAGE_SHIFT) : 0UL)
static unsigned long shared_align_offset(unsigned long filp_pgoff, unsigned long pgoff) @@ -116,7 +111,7 @@ static unsigned long arch_get_unmapped_a do_color_align = 0; if (filp || (flags & MAP_SHARED)) do_color_align = 1; - filp_pgoff = GET_FILP_PGOFF(filp, addr); + filp_pgoff = GET_FILP_PGOFF(filp);
if (flags & MAP_FIXED) { /* Even MAP_FIXED mappings must reside within TASK_SIZE */ --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -3466,6 +3466,8 @@ static unsigned long io_uring_mmu_get_un * - use the kernel virtual address of the shared io_uring context * (instead of the userspace-provided address, which has to be 0UL * anyway). + * - use the same pgoff which the get_unmapped_area() uses to + * calculate the page colouring. * For architectures without such aliasing requirements, the * architecture will return any suitable mapping because addr is 0. */ @@ -3474,6 +3476,7 @@ static unsigned long io_uring_mmu_get_un pgoff = 0; /* has been translated to ptr above */ #ifdef SHM_COLOUR addr = (uintptr_t) ptr; + pgoff = addr >> PAGE_SHIFT; #else addr = 0UL; #endif