Automatically round address ranges requested from rphysmap() to page boundaries. Other physmap() variants were not changed so this is safe regarding unmapping.
I had also to shorten the readbility defines for the physmap_common parameters to make the calls fit a single line.
Signed-off-by: Stefan Tauner stefan.tauner@student.tuwien.ac.at --- physmap.c | 61 ++++++++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 40 insertions(+), 21 deletions(-)
diff --git a/physmap.c b/physmap.c index 2c90091..b248f92 100644 --- a/physmap.c +++ b/physmap.c @@ -208,12 +208,35 @@ void physunmap(void *virt_addr, size_t len) } #endif
-#define PHYSMAP_NOFAIL 0 -#define PHYSMAP_MAYFAIL 1 -#define PHYSMAP_RW 0 -#define PHYSMAP_RO 1 -#define PHYSMAP_NOCLEANUP 0 -#define PHYSMAP_CLEANUP 1 +#define PHYSM_NOFAIL 0 +#define PHYSM_MAYFAIL 1 +#define PHYSM_RW 0 +#define PHYSM_RO 1 +#define PHYSM_NOCLEANUP 0 +#define PHYSM_CLEANUP 1 +#define PHYSM_EXACT 0 +#define PHYSM_ROUND 1 + +/* 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=%" PRIxPTR "\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 undo_physmap_data { void *virt_addr; @@ -233,24 +256,18 @@ static int undo_physmap(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%0*" PRIxPTR ", unaligned size 0x%lx.\n", - descr, PRIxPTR_WIDTH, phys_addr, (unsigned long)len); - } - - if ((getpagesize() - 1) & phys_addr) { - msg_perr("Mapping %s, 0x%lx bytes at unaligned 0x%0*" PRIxPTR ".\n", - descr, (unsigned long)len, PRIxPTR_WIDTH, phys_addr); - } + if (round) + offset = round_to_page_boundaries(&phys_addr, &len);
if (readonly) virt_addr = sys_physmap_ro_cached(phys_addr, len); @@ -276,7 +293,9 @@ 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); }
@@ -295,7 +314,7 @@ 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); if (!mayfail) @@ -305,17 +324,17 @@ unmap_out:
void *physmap(const char *descr, uintptr_t phys_addr, size_t len) { - return physmap_common(descr, phys_addr, len, PHYSMAP_NOFAIL, PHYSMAP_RW, PHYSMAP_NOCLEANUP); + return physmap_common(descr, phys_addr, len, PHYSM_NOFAIL, PHYSM_RW, PHYSM_NOCLEANUP, PHYSM_EXACT); }
void *rphysmap(const char *descr, uintptr_t phys_addr, size_t len) { - return physmap_common(descr, phys_addr, len, PHYSMAP_NOFAIL, PHYSMAP_RW, PHYSMAP_CLEANUP); + return physmap_common(descr, phys_addr, len, PHYSM_NOFAIL, PHYSM_RW, PHYSM_CLEANUP, PHYSM_ROUND); }
void *physmap_try_ro(const char *descr, uintptr_t phys_addr, size_t len) { - return physmap_common(descr, phys_addr, len, PHYSMAP_MAYFAIL, PHYSMAP_RO, PHYSMAP_NOCLEANUP); + return physmap_common(descr, phys_addr, len, PHYSM_MAYFAIL, PHYSM_RO, PHYSM_NOCLEANUP, PHYSM_EXACT); }
/* MSR abstraction implementations for Linux, OpenBSD, FreeBSD/Dragonfly, OSX, libpayload
-
Stefan Tauner