On Thu, Jun 18, 2020 at 11:57:27PM -0700, Kenneth R. Crudup wrote:
>
> On Fri, 19 Jun 2020, Christoph Hellwig wrote:
>
> > That is indeed really strange, as that commit is just a rename.
> > Well, Linus also added swapping of the argument order, but again it
> > shouldn't change much.
>
> Thing is, there's other examples of the previous version in the kernel tree-
> any
> chance there's a usage conflict (Thunderbolt has a ROM in it, maybe something
> in
> "probe_roms.c"? (Just guessing, no idea):
Maybe. But nothing looks strange there. Just to re-reconfirm, you had to
revert "maccess: rename probe_kernel_address to get_kernel_nofault",
"maccess: make get_kernel_nofault() check for minimal type compatibility"
wasn't enough?
Below is a patch to do a "partial revert" for probe_roms.c. I'd be
totally surprised if it changes anything from staring at it for while,
but anyway..
diff --git a/arch/x86/kernel/probe_roms.c b/arch/x86/kernel/probe_roms.c
index 9e1def3744f220..70ff3267b4f373 100644
--- a/arch/x86/kernel/probe_roms.c
+++ b/arch/x86/kernel/probe_roms.c
@@ -22,6 +22,9 @@
#include <asm/io.h>
#include <asm/setup_arch.h>
+#define probe_kernel_address(addr, retval) \
+ copy_from_kernel_nofault(&retval, addr, sizeof(retval))
+
static struct resource system_rom_resource = {
.name = "System ROM",
.start = 0xf0000,
@@ -99,7 +102,7 @@ static bool probe_list(struct pci_dev *pdev, unsigned short
vendor,
unsigned short device;
do {
- if (get_kernel_nofault(device, rom_list) != 0)
+ if (probe_kernel_address(rom_list, device) != 0)
device = 0;
if (device && match_id(pdev, vendor, device))
@@ -125,13 +128,13 @@ static struct resource *find_oprom(struct pci_dev *pdev)
break;
rom = isa_bus_to_virt(res->start);
- if (get_kernel_nofault(offset, rom + 0x18) != 0)
+ if (probe_kernel_address(rom + 0x18, offset) != 0)
continue;
- if (get_kernel_nofault(vendor, rom + offset + 0x4) != 0)
+ if (probe_kernel_address(rom + offset + 0x4, vendor) != 0)
continue;
- if (get_kernel_nofault(device, rom + offset + 0x6) != 0)
+ if (probe_kernel_address(rom + offset + 0x6, device) != 0)
continue;
if (match_id(pdev, vendor, device)) {
@@ -139,8 +142,8 @@ static struct resource *find_oprom(struct pci_dev *pdev)
break;
}
- if (get_kernel_nofault(list, rom + offset + 0x8) == 0 &&
- get_kernel_nofault(rev, rom + offset + 0xc) == 0 &&
+ if (probe_kernel_address(rom + offset + 0x8, list) == 0 &&
+ probe_kernel_address(rom + offset + 0xc, rev) == 0 &&
rev >= 3 && list &&
probe_list(pdev, vendor, rom + offset + list)) {
oprom = res;
@@ -183,14 +186,14 @@ static int __init romsignature(const unsigned char *rom)
const unsigned short * const ptr = (const unsigned short *)rom;
unsigned short sig;
- return get_kernel_nofault(sig, ptr) == 0 && sig == ROMSIGNATURE;
+ return probe_kernel_address(ptr, sig) == 0 && sig == ROMSIGNATURE;
}
static int __init romchecksum(const unsigned char *rom, unsigned long length)
{
unsigned char sum, c;
- for (sum = 0; length && get_kernel_nofault(c, rom++) == 0; length--)
+ for (sum = 0; length && probe_kernel_address(rom++, c) == 0; length--)
sum += c;
return !length && !sum;
}
@@ -211,7 +214,7 @@ void __init probe_roms(void)
video_rom_resource.start = start;
- if (get_kernel_nofault(c, rom + 2) != 0)
+ if (probe_kernel_address(rom + 2, c) != 0)
continue;
/* 0 < length <= 0x7f * 512, historically */
@@ -249,7 +252,7 @@ void __init probe_roms(void)
if (!romsignature(rom))
continue;
- if (get_kernel_nofault(c, rom + 2) != 0)
+ if (probe_kernel_address(rom + 2, c) != 0)
continue;
/* 0 < length <= 0x7f * 512, historically */
