Re: [PATCH v5 17/32] x86/mm: Add support to access boot related data in the clear

Borislav Petkov
2017-05-21T07:17:09Z

On Fri, May 19, 2017 at 03:50:32PM -0500, Tom Lendacky wrote:
> The "worker" function would be doing the loop through the setup data,
> but since the setup data is mapped inside the loop I can't do the __init
> calling the non-init function and still hope to consolidate the code.
> Maybe I'm missing something here...

Hmm, I see what you mean. But the below change ontop doesn't fire any
warnings here. Maybe your .config has something set which I don't...

---
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 55317ba3b6dc..199c983192ae 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -515,71 +515,50 @@ static bool memremap_is_efi_data(resource_size_t phys_addr,
* Examine the physical address to determine if it is boot data by checking
* it against the boot params setup_data chain.
*/
-static bool memremap_is_setup_data(resource_size_t phys_addr,
- unsigned long size)
+static bool
+__memremap_is_setup_data(resource_size_t phys_addr, unsigned long size, bool early)
{
struct setup_data *data;
u64 paddr, paddr_next;
+ u32 len;

paddr = boot_params.hdr.setup_data;
while (paddr) {
- bool is_setup_data = false;

if (phys_addr == paddr)
return true;

- data = memremap(paddr, sizeof(*data),
- MEMREMAP_WB | MEMREMAP_DEC);
+ if (early)
+ data = early_memremap_decrypted(paddr, sizeof(*data));
+ else
+ data = memremap(paddr, sizeof(*data), MEMREMAP_WB | MEMREMAP_DEC);

paddr_next = data->next;
+ len = data->len;

- if ((phys_addr > paddr) && (phys_addr < (paddr + data->len)))
- is_setup_data = true;
+ if (early)
+ early_memunmap(data, sizeof(*data));
+ else
+ memunmap(data);

- memunmap(data);

- if (is_setup_data)
+ if ((phys_addr > paddr) && (phys_addr < (paddr + data->len)))
return true;

paddr = paddr_next;
}
-
return false;
}

-/*
- * Examine the physical address to determine if it is boot data by checking
- * it against the boot params setup_data chain (early boot version).
- */
static bool __init early_memremap_is_setup_data(resource_size_t phys_addr,
unsigned long size)
{
- struct setup_data *data;
- u64 paddr, paddr_next;
-
- paddr = boot_params.hdr.setup_data;
- while (paddr) {
- bool is_setup_data = false;
-
- if (phys_addr == paddr)
- return true;
-
- data = early_memremap_decrypted(paddr, sizeof(*data));
-
- paddr_next = data->next;
-
- if ((phys_addr > paddr) && (phys_addr < (paddr + data->len)))
- is_setup_data = true;
-
- early_memunmap(data, sizeof(*data));
-
- if (is_setup_data)
- return true;
-
- paddr = paddr_next;
- }
+ return __memremap_is_setup_data(phys_addr, size, true);
+}

- return false;
+static bool memremap_is_setup_data(resource_size_t phys_addr, unsigned long size)
+{
+ return __memremap_is_setup_data(phys_addr, size, false);
}

/*

--
Regards/Gruss,
Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.