RISC-V Fixes for 5.13-rc3

* A fix to properly set the memory size, which fixes 32-bit systems.
 * A fix to allow the initrd to load anywhere in memory, rather that
   restricting it to the first 256MiB.
 * A fix for the mem= parameter on 64-bit systems, to properly account
   for the maximum supported memory now that the kernel is outside the
   linear map.
 * A fix to avoid installing mappings into the last 4KiB of memory, which
   conflicts with error values.
 * A fix to avoid the stack from being freed while it is being walked.
 * A handful of fixes to the new copy to/from user routines.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEKzw3R0RoQ7JKlDp6LhMZ81+7GIkFAmD8eXcTHHBhbG1lckBk
 YWJiZWx0LmNvbQAKCRAuExnzX7sYiaMuEADHGjJFSzFkPXAj1ROZ7gmbVkife7u3
 3wouD25dUQ92a9Smo5D/RthmqoZna7vOjxdtPGdhL3+LvFkB//tkZRRIOYxteJRp
 8+RI9wChkx3OeeJ1bMG6/1vS/Rf7eWmqjxSIYyKdmy4TnTb1kj4/XtHxkANzoCTK
 1wG9T3diKae5PORvZEz+FVd2I0/1sIWnsVtageBHHBuLrAktOHywRqJ+2Wif5ilT
 5SJPn2TPKxBI9XFDdlN8IsehSgF6+bb9R/vuOZn4Zl15zXy8NrD+LcNk06u07+If
 gzJ6eJ4jCeiEau1L2wyVdFh0r+mt3vQcJkbqb7XdoCfDRqYbsCaFTNUKy1PjYCh5
 UsgSWwyEVNiCDvv7na0n2Ptcki6icnDkKwvYhyzBhga0mYs1/GAleicKvtQ4uiVA
 ymz4N3Dk/UObtI7qeTlUKC2hfsWwvM/L61BXS+AleVryI9AKarwerMezsaFP3eNm
 q+IFsPOQFEaJdG1IX5G1Y7gHf2RWhQXJz/7zxEUg+VKOhYrX826E96Kp7UYKgQD8
 hB8D5XZFTaNY8CsA3q7TI/WUuv4GyQeEEaI3YWPppWkpqfoUzPFy26GjhEdFecuU
 oCIjgraXKltN1fLDGqQEspLQwxJ3+4YLAKVMg3ggPk/lcMokLZgmj7i2GbjMwVXj
 VbZAfWhBhsfMXQ==
 =gyPr
 -----END PGP SIGNATURE-----

Merge tag 'riscv-for-linus-5.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Palmer Dabbelt:

 - properly set the memory size, which fixes 32-bit systems

 - allow initrd to load anywhere in memory, rather that restricting it
   to the first 256MiB

 - fix the 'mem=' parameter on 64-bit systems to properly account for
   the maximum supported memory now that the kernel is outside the
   linear map

 - avoid installing mappings into the last 4KiB of memory, which
   conflicts with error values

 - avoid the stack from being freed while it is being walked

 - a handful of fixes to the new copy to/from user routines

* tag 'riscv-for-linus-5.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: __asm_copy_to-from_user: Fix: Typos in comments
  riscv: __asm_copy_to-from_user: Remove unnecessary size check
  riscv: __asm_copy_to-from_user: Fix: fail on RV32
  riscv: __asm_copy_to-from_user: Fix: overrun copy
  riscv: stacktrace: pin the task's stack in get_wchan
  riscv: Make sure the kernel mapping does not overlap with IS_ERR_VALUE
  riscv: Make sure the linear mapping does not use the kernel mapping
  riscv: Fix memory_limit for 64-bit kernel
  RISC-V: load initrd wherever it fits into memory
  riscv: Fix 32-bit RISC-V boot failure
This commit is contained in:
Linus Torvalds 2021-07-24 15:34:04 -07:00
commit 6498f61518
4 changed files with 48 additions and 21 deletions

View file

@ -27,10 +27,10 @@ int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
#define ARCH_EFI_IRQ_FLAGS_MASK (SR_IE | SR_SPIE)
/* Load initrd at enough distance from DRAM start */
/* Load initrd anywhere in system RAM */
static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
{
return image_addr + SZ_256M;
return ULONG_MAX;
}
#define alloc_screen_info(x...) (&screen_info)

View file

@ -132,8 +132,12 @@ unsigned long get_wchan(struct task_struct *task)
{
unsigned long pc = 0;
if (likely(task && task != current && !task_is_running(task)))
if (likely(task && task != current && !task_is_running(task))) {
if (!try_get_task_stack(task))
return 0;
walk_stackframe(task, NULL, save_wchan, &pc);
put_task_stack(task);
}
return pc;
}

View file

@ -30,23 +30,23 @@ ENTRY(__asm_copy_from_user)
* t0 - end of uncopied dst
*/
add t0, a0, a2
bgtu a0, t0, 5f
/*
* Use byte copy only if too small.
* SZREG holds 4 for RV32 and 8 for RV64
*/
li a3, 8*SZREG /* size must be larger than size in word_copy */
li a3, 9*SZREG /* size must be larger than size in word_copy */
bltu a2, a3, .Lbyte_copy_tail
/*
* Copy first bytes until dst is align to word boundary.
* Copy first bytes until dst is aligned to word boundary.
* a0 - start of dst
* t1 - start of aligned dst
*/
addi t1, a0, SZREG-1
andi t1, t1, ~(SZREG-1)
/* dst is already aligned, skip */
beq a0, t1, .Lskip_first_bytes
beq a0, t1, .Lskip_align_dst
1:
/* a5 - one byte for copying data */
fixup lb a5, 0(a1), 10f
@ -55,7 +55,7 @@ ENTRY(__asm_copy_from_user)
addi a0, a0, 1 /* dst */
bltu a0, t1, 1b /* t1 - start of aligned dst */
.Lskip_first_bytes:
.Lskip_align_dst:
/*
* Now dst is aligned.
* Use shift-copy if src is misaligned.
@ -72,10 +72,9 @@ ENTRY(__asm_copy_from_user)
*
* a0 - start of aligned dst
* a1 - start of aligned src
* a3 - a1 & mask:(SZREG-1)
* t0 - end of aligned dst
*/
addi t0, t0, -(8*SZREG-1) /* not to over run */
addi t0, t0, -(8*SZREG) /* not to over run */
2:
fixup REG_L a4, 0(a1), 10f
fixup REG_L a5, SZREG(a1), 10f
@ -97,7 +96,7 @@ ENTRY(__asm_copy_from_user)
addi a1, a1, 8*SZREG
bltu a0, t0, 2b
addi t0, t0, 8*SZREG-1 /* revert to original value */
addi t0, t0, 8*SZREG /* revert to original value */
j .Lbyte_copy_tail
.Lshift_copy:
@ -107,7 +106,7 @@ ENTRY(__asm_copy_from_user)
* For misaligned copy we still perform aligned word copy, but
* we need to use the value fetched from the previous iteration and
* do some shifts.
* This is safe because reading less than a word size.
* This is safe because reading is less than a word size.
*
* a0 - start of aligned dst
* a1 - start of src
@ -117,7 +116,7 @@ ENTRY(__asm_copy_from_user)
*/
/* calculating aligned word boundary for dst */
andi t1, t0, ~(SZREG-1)
/* Converting unaligned src to aligned arc */
/* Converting unaligned src to aligned src */
andi a1, a1, ~(SZREG-1)
/*
@ -125,11 +124,11 @@ ENTRY(__asm_copy_from_user)
* t3 - prev shift
* t4 - current shift
*/
slli t3, a3, LGREG
slli t3, a3, 3 /* converting bytes in a3 to bits */
li a5, SZREG*8
sub t4, a5, t3
/* Load the first word to combine with seceond word */
/* Load the first word to combine with second word */
fixup REG_L a5, 0(a1), 10f
3:
@ -161,7 +160,7 @@ ENTRY(__asm_copy_from_user)
* a1 - start of remaining src
* t0 - end of remaining dst
*/
bgeu a0, t0, 5f
bgeu a0, t0, .Lout_copy_user /* check if end of copy */
4:
fixup lb a5, 0(a1), 10f
addi a1, a1, 1 /* src */
@ -169,7 +168,7 @@ ENTRY(__asm_copy_from_user)
addi a0, a0, 1 /* dst */
bltu a0, t0, 4b /* t0 - end of dst */
5:
.Lout_copy_user:
/* Disable access to user memory */
csrc CSR_STATUS, t6
li a0, 0

View file

@ -127,10 +127,17 @@ void __init mem_init(void)
}
/*
* The default maximal physical memory size is -PAGE_OFFSET,
* limit the memory size via mem.
* The default maximal physical memory size is -PAGE_OFFSET for 32-bit kernel,
* whereas for 64-bit kernel, the end of the virtual address space is occupied
* by the modules/BPF/kernel mappings which reduces the available size of the
* linear mapping.
* Limit the memory size via mem.
*/
#ifdef CONFIG_64BIT
static phys_addr_t memory_limit = -PAGE_OFFSET - SZ_4G;
#else
static phys_addr_t memory_limit = -PAGE_OFFSET;
#endif
static int __init early_mem(char *p)
{
@ -152,7 +159,7 @@ static void __init setup_bootmem(void)
{
phys_addr_t vmlinux_end = __pa_symbol(&_end);
phys_addr_t vmlinux_start = __pa_symbol(&_start);
phys_addr_t max_mapped_addr = __pa(~(ulong)0);
phys_addr_t __maybe_unused max_mapped_addr;
phys_addr_t dram_end;
#ifdef CONFIG_XIP_KERNEL
@ -175,14 +182,21 @@ static void __init setup_bootmem(void)
memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
dram_end = memblock_end_of_DRAM();
#ifndef CONFIG_64BIT
/*
* memblock allocator is not aware of the fact that last 4K bytes of
* the addressable memory can not be mapped because of IS_ERR_VALUE
* macro. Make sure that last 4k bytes are not usable by memblock
* if end of dram is equal to maximum addressable memory.
* if end of dram is equal to maximum addressable memory. For 64-bit
* kernel, this problem can't happen here as the end of the virtual
* address space is occupied by the kernel mapping then this check must
* be done in create_kernel_page_table.
*/
max_mapped_addr = __pa(~(ulong)0);
if (max_mapped_addr == (dram_end - 1))
memblock_set_current_limit(max_mapped_addr - 4096);
#endif
min_low_pfn = PFN_UP(memblock_start_of_DRAM());
max_low_pfn = max_pfn = PFN_DOWN(dram_end);
@ -570,6 +584,14 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
BUG_ON((kernel_map.phys_addr % map_size) != 0);
#ifdef CONFIG_64BIT
/*
* The last 4K bytes of the addressable memory can not be mapped because
* of IS_ERR_VALUE macro.
*/
BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K);
#endif
pt_ops.alloc_pte = alloc_pte_early;
pt_ops.get_pte_virt = get_pte_virt_early;
#ifndef __PAGETABLE_PMD_FOLDED
@ -709,6 +731,8 @@ static void __init setup_vm_final(void)
if (start <= __pa(PAGE_OFFSET) &&
__pa(PAGE_OFFSET) < end)
start = __pa(PAGE_OFFSET);
if (end >= __pa(PAGE_OFFSET) + memory_limit)
end = __pa(PAGE_OFFSET) + memory_limit;
map_size = best_map_size(start, end - start);
for (pa = start; pa < end; pa += map_size) {