Automatically round address ranges requested from physmap_autocleanup()
to page boundaries. Other physmap() variants were not changed so this
is safe regarding unmapping.
Signed-off-by: Stefan Tauner <stefan.tauner(a)student.tuwien.ac.at>
---
physmap.c | 47 ++++++++++++++++++++++++++++++++---------------
1 file changed, 32 insertions(+), 15 deletions(-)
diff --git a/physmap.c b/physmap.c
index 8b9fea7..ea87d1a 100644
--- a/physmap.c
+++ b/physmap.c
@@ -218,6 +218,27 @@ void physunmap(void *virt_addr, size_t len)
}
#endif
+/* Round start to nearest page boundary below and set len so that the resulting
+ * address range ends at the lowest possible page boundary where the original
+ * address range is still entirely contained. It returns the difference between
+ * the rounded start address and the original start address. */
+static uintptr_t round_to_page_boundaries(uintptr_t *start, size_t *len)
+{
+ uintptr_t page_size = getpagesize();
+ uintptr_t page_mask = ~(page_size-1);
+ uintptr_t end = *start + *len;
+ uintptr_t old_start = *start;
+ msg_gspew("page_size=%lu\n", page_size);
+ msg_gspew("pre-rounding: start=0x%0*" PRIxPTR ", len=0x%0zx, end=0x%0*" PRIxPTR "\n",
+ PRIxPTR_WIDTH, *start, *len, PRIxPTR_WIDTH, end);
+ *start = *start & page_mask;
+ end = (end + page_size - 1) & page_mask;
+ *len = end - *start;
+ msg_gspew("post-rounding: start=0x%0*" PRIxPTR ", len=0x%0zx, end=0x%0*" PRIxPTR "\n",
+ PRIxPTR_WIDTH, *start, *len, PRIxPTR_WIDTH, *start + *len);
+ return old_start - *start;
+}
+
struct physmap_stutdown_data {
void *addr;
size_t len;
@@ -236,24 +257,18 @@ static int physmap_shutdown(void *data)
}
static void *physmap_common(const char *descr, uintptr_t phys_addr, size_t len, bool mayfail,
- bool readonly, bool autocleanup)
+ bool readonly, bool autocleanup, bool round)
{
void *virt_addr;
+ uintptr_t offset = 0;
if (len == 0) {
msg_pspew("Not mapping %s, zero size at 0x%0*" PRIxPTR ".\n", descr, PRIxPTR_WIDTH, phys_addr);
return ERROR_PTR;
}
- if ((getpagesize() - 1) & len) {
- msg_perr("Mapping %s at 0x%08lx, unaligned size 0x%lx.\n",
- descr, phys_addr, (unsigned long)len);
- }
-
- if ((getpagesize() - 1) & phys_addr) {
- msg_perr("Mapping %s, 0x%lx bytes at unaligned 0x%08lx.\n",
- descr, (unsigned long)len, phys_addr);
- }
+ if (round)
+ offset = round_to_page_boundaries(&phys_addr, &len);
if (readonly)
virt_addr = sys_physmap_ro_cached(phys_addr, len);
@@ -279,7 +294,9 @@ static void *physmap_common(const char *descr, uintptr_t phys_addr, size_t len,
"and reboot, or reboot into\n"
"single user mode.\n");
#endif
- if (!mayfail)
+ if (mayfail)
+ return ERROR_PTR;
+ else
exit(3);
}
@@ -298,7 +315,7 @@ static void *physmap_common(const char *descr, uintptr_t phys_addr, size_t len,
}
}
- return virt_addr;
+ return virt_addr + offset;
unmap_out:
physunmap(virt_addr, len);
return ERROR_PTR;
@@ -306,17 +323,17 @@ unmap_out:
void *physmap(const char *descr, uintptr_t phys_addr, size_t len)
{
- return physmap_common(descr, phys_addr, len, false, false, false);
+ return physmap_common(descr, phys_addr, len, false, false, false, false);
}
void *physmap_autocleanup(const char *descr, uintptr_t phys_addr, size_t len)
{
- return physmap_common(descr, phys_addr, len, false, false, true);
+ return physmap_common(descr, phys_addr, len, false, false, true, true);
}
void *physmap_try_ro(const char *descr, uintptr_t phys_addr, size_t len)
{
- return physmap_common(descr, phys_addr, len, true, true, false);
+ return physmap_common(descr, phys_addr, len, true, true, false, false);
}
#if defined(__i386__) || defined(__x86_64__)
--
Kind regards, Stefan Tauner