xen/common/efi/boot.c | 45 +++++++++++++++++++++++++++++-------------- 1 file changed, 31 insertions(+), 14 deletions(-)
Although code is compiled with -fpic option data is not position
independent. This causes data pointer to become invalid if
code is not relocated properly which is what happens for
efi_multiboot2 which is called by multiboot entry code.
Code tested adding
PrintErrMesg(L"Test message", EFI_BUFFER_TOO_SMALL);
in efi_multiboot2 before calling efi_arch_edd (this function
can potentially call PrintErrMesg).
Before the patch (XenServer installation on Qemu, xen replaced
with vanilla xen.gz):
Booting `XenServer (Serial)'Booting `XenServer (Serial)'
Test message: !!!! X64 Exception Type - 0E(#PF - Page-Fault) CPU Apic ID - 00000000 !!!!
ExceptionData - 0000000000000000 I:0 R:0 U:0 W:0 P:0 PK:0 SS:0 SGX:0
RIP - 000000007DC29E46, CS - 0000000000000038, RFLAGS - 0000000000210246
RAX - 0000000000000000, RCX - 0000000000000050, RDX - 0000000000000000
RBX - 000000007DAB4558, RSP - 000000007EFA1200, RBP - 0000000000000000
RSI - FFFF82D040467A88, RDI - 0000000000000000
R8 - 000000007EFA1238, R9 - 000000007EFA1230, R10 - 0000000000000000
R11 - 000000007CF42665, R12 - FFFF82D040467A88, R13 - 000000007EFA1228
R14 - 000000007EFA1225, R15 - 000000007DAB45A8
DS - 0000000000000030, ES - 0000000000000030, FS - 0000000000000030
GS - 0000000000000030, SS - 0000000000000030
CR0 - 0000000080010033, CR2 - FFFF82D040467A88, CR3 - 000000007EC01000
CR4 - 0000000000000668, CR8 - 0000000000000000
DR0 - 0000000000000000, DR1 - 0000000000000000, DR2 - 0000000000000000
DR3 - 0000000000000000, DR6 - 00000000FFFF0FF0, DR7 - 0000000000000400
GDTR - 000000007E9E2000 0000000000000047, LDTR - 0000000000000000
IDTR - 000000007E4E5018 0000000000000FFF, TR - 0000000000000000
FXSAVE_STATE - 000000007EFA0E60
!!!! Find image based on IP(0x7DC29E46) (No PDB) (ImageBase=000000007DC28000, EntryPoint=000000007DC2B917) !!!!
After the patch:
Booting `XenServer (Serial)'Booting `XenServer (Serial)'
Test message: Buffer too small
BdsDxe: loading Boot0000 "UiApp" from Fv(7CB8BDC9-F8EB-4F34-AAEA-3EE4AF6516A1)/FvFile(462CAA21-7614-4503-836E-8AB6F4662331)
BdsDxe: starting Boot0000 "UiApp" from Fv(7CB8BDC9-F8EB-4F34-AAEA-3EE4AF6516A1)/FvFile(462CAA21-7614-4503-836E-8AB6F4662331)
Signed-off-by: Frediano Ziglio <frediano.ziglio@cloud.com>
---
xen/common/efi/boot.c | 45 +++++++++++++++++++++++++++++--------------
1 file changed, 31 insertions(+), 14 deletions(-)
diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
index efbec00af9..e6aa9271ed 100644
--- a/xen/common/efi/boot.c
+++ b/xen/common/efi/boot.c
@@ -287,19 +287,36 @@ static bool __init match_guid(const EFI_GUID *guid1, const EFI_GUID *guid2)
/* generic routine for printing error messages */
static void __init PrintErrMesg(const CHAR16 *mesg, EFI_STATUS ErrCode)
{
- static const CHAR16* const ErrCodeToStr[] __initconstrel = {
- [~EFI_ERROR_MASK & EFI_NOT_FOUND] = L"Not found",
- [~EFI_ERROR_MASK & EFI_NO_MEDIA] = L"The device has no media",
- [~EFI_ERROR_MASK & EFI_MEDIA_CHANGED] = L"Media changed",
- [~EFI_ERROR_MASK & EFI_DEVICE_ERROR] = L"Device error",
- [~EFI_ERROR_MASK & EFI_VOLUME_CORRUPTED] = L"Volume corrupted",
- [~EFI_ERROR_MASK & EFI_ACCESS_DENIED] = L"Access denied",
- [~EFI_ERROR_MASK & EFI_OUT_OF_RESOURCES] = L"Out of resources",
- [~EFI_ERROR_MASK & EFI_VOLUME_FULL] = L"Volume is full",
- [~EFI_ERROR_MASK & EFI_SECURITY_VIOLATION] = L"Security violation",
- [~EFI_ERROR_MASK & EFI_CRC_ERROR] = L"CRC error",
- [~EFI_ERROR_MASK & EFI_COMPROMISED_DATA] = L"Compromised data",
- [~EFI_ERROR_MASK & EFI_BUFFER_TOO_SMALL] = L"Buffer too small",
+#define ERROR_MESSAGE_LIST \
+ ERROR_MESSAGE(EFI_NOT_FOUND, "Not found") \
+ ERROR_MESSAGE(EFI_NO_MEDIA, "The device has no media") \
+ ERROR_MESSAGE(EFI_MEDIA_CHANGED, "Media changed") \
+ ERROR_MESSAGE(EFI_DEVICE_ERROR, "Device error") \
+ ERROR_MESSAGE(EFI_VOLUME_CORRUPTED, "Volume corrupted") \
+ ERROR_MESSAGE(EFI_ACCESS_DENIED, "Access denied") \
+ ERROR_MESSAGE(EFI_OUT_OF_RESOURCES, "Out of resources") \
+ ERROR_MESSAGE(EFI_VOLUME_FULL, "Volume is full") \
+ ERROR_MESSAGE(EFI_SECURITY_VIOLATION, "Security violation") \
+ ERROR_MESSAGE(EFI_CRC_ERROR, "CRC error") \
+ ERROR_MESSAGE(EFI_COMPROMISED_DATA, "Compromised data") \
+ ERROR_MESSAGE(EFI_BUFFER_TOO_SMALL, "Buffer too small")
+
+ static const struct ErrorStrings {
+ CHAR16 start;
+#undef ERROR_MESSAGE
+#define ERROR_MESSAGE(code, str) CHAR16 msg_ ## code[sizeof(str)];
+ ERROR_MESSAGE_LIST
+ } ErrorStrings __initconst = {
+ 0
+#undef ERROR_MESSAGE
+#define ERROR_MESSAGE(code, str) , L ## str
+ ERROR_MESSAGE_LIST
+ };
+ static const uint16_t ErrCodeToStr[] __initconst = {
+#undef ERROR_MESSAGE
+#define ERROR_MESSAGE(code, str) \
+ [~EFI_ERROR_MASK & code] = offsetof(struct ErrorStrings, msg_ ## code),
+ ERROR_MESSAGE_LIST
};
EFI_STATUS ErrIdx = ErrCode & ~EFI_ERROR_MASK;
@@ -308,7 +325,7 @@ static void __init PrintErrMesg(const CHAR16 *mesg, EFI_STATUS ErrCode)
PrintErr(L": ");
if( (ErrIdx < ARRAY_SIZE(ErrCodeToStr)) && ErrCodeToStr[ErrIdx] )
- mesg = ErrCodeToStr[ErrIdx];
+ mesg = (CHAR16*) ((char*) &ErrorStrings + ErrCodeToStr[ErrIdx]);
else
{
PrintErr(L"ErrCode: ");
--
2.46.0On 19.08.2024 13:07, Frediano Ziglio wrote:
> --- a/xen/common/efi/boot.c
> +++ b/xen/common/efi/boot.c
> @@ -287,19 +287,36 @@ static bool __init match_guid(const EFI_GUID *guid1, const EFI_GUID *guid2)
> /* generic routine for printing error messages */
> static void __init PrintErrMesg(const CHAR16 *mesg, EFI_STATUS ErrCode)
> {
> - static const CHAR16* const ErrCodeToStr[] __initconstrel = {
> - [~EFI_ERROR_MASK & EFI_NOT_FOUND] = L"Not found",
> - [~EFI_ERROR_MASK & EFI_NO_MEDIA] = L"The device has no media",
> - [~EFI_ERROR_MASK & EFI_MEDIA_CHANGED] = L"Media changed",
> - [~EFI_ERROR_MASK & EFI_DEVICE_ERROR] = L"Device error",
> - [~EFI_ERROR_MASK & EFI_VOLUME_CORRUPTED] = L"Volume corrupted",
> - [~EFI_ERROR_MASK & EFI_ACCESS_DENIED] = L"Access denied",
> - [~EFI_ERROR_MASK & EFI_OUT_OF_RESOURCES] = L"Out of resources",
> - [~EFI_ERROR_MASK & EFI_VOLUME_FULL] = L"Volume is full",
> - [~EFI_ERROR_MASK & EFI_SECURITY_VIOLATION] = L"Security violation",
> - [~EFI_ERROR_MASK & EFI_CRC_ERROR] = L"CRC error",
> - [~EFI_ERROR_MASK & EFI_COMPROMISED_DATA] = L"Compromised data",
> - [~EFI_ERROR_MASK & EFI_BUFFER_TOO_SMALL] = L"Buffer too small",
> +#define ERROR_MESSAGE_LIST \
> + ERROR_MESSAGE(EFI_NOT_FOUND, "Not found") \
> + ERROR_MESSAGE(EFI_NO_MEDIA, "The device has no media") \
> + ERROR_MESSAGE(EFI_MEDIA_CHANGED, "Media changed") \
> + ERROR_MESSAGE(EFI_DEVICE_ERROR, "Device error") \
> + ERROR_MESSAGE(EFI_VOLUME_CORRUPTED, "Volume corrupted") \
> + ERROR_MESSAGE(EFI_ACCESS_DENIED, "Access denied") \
> + ERROR_MESSAGE(EFI_OUT_OF_RESOURCES, "Out of resources") \
> + ERROR_MESSAGE(EFI_VOLUME_FULL, "Volume is full") \
> + ERROR_MESSAGE(EFI_SECURITY_VIOLATION, "Security violation") \
> + ERROR_MESSAGE(EFI_CRC_ERROR, "CRC error") \
> + ERROR_MESSAGE(EFI_COMPROMISED_DATA, "Compromised data") \
> + ERROR_MESSAGE(EFI_BUFFER_TOO_SMALL, "Buffer too small")
> +
> + static const struct ErrorStrings {
__initconst?
> + CHAR16 start;
> +#undef ERROR_MESSAGE
> +#define ERROR_MESSAGE(code, str) CHAR16 msg_ ## code[sizeof(str)];
> + ERROR_MESSAGE_LIST
> + } ErrorStrings __initconst = {
> + 0
> +#undef ERROR_MESSAGE
> +#define ERROR_MESSAGE(code, str) , L ## str
> + ERROR_MESSAGE_LIST
> + };
> + static const uint16_t ErrCodeToStr[] __initconst = {
> +#undef ERROR_MESSAGE
> +#define ERROR_MESSAGE(code, str) \
> + [~EFI_ERROR_MASK & code] = offsetof(struct ErrorStrings, msg_ ## code),
> + ERROR_MESSAGE_LIST
> };
> EFI_STATUS ErrIdx = ErrCode & ~EFI_ERROR_MASK;
>
> @@ -308,7 +325,7 @@ static void __init PrintErrMesg(const CHAR16 *mesg, EFI_STATUS ErrCode)
> PrintErr(L": ");
>
> if( (ErrIdx < ARRAY_SIZE(ErrCodeToStr)) && ErrCodeToStr[ErrIdx] )
> - mesg = ErrCodeToStr[ErrIdx];
> + mesg = (CHAR16*) ((char*) &ErrorStrings + ErrCodeToStr[ErrIdx]);
Please never cast away const. Also (nit) please put the blanks at the right
places. Finally instead of casting to char * (something string-like)
intermediately, perhaps better cast to void *? Taken together
mesg = (const CHAR16 *)((const void *)&ErrorStrings + ErrCodeToStr[ErrIdx]);
(which looks like it'll then also need line-wrapping).
Further please add an appropriate Fixes: tag.
Jan
On Mon, Aug 19, 2024 at 12:35 PM Jan Beulich <jbeulich@suse.com> wrote:
>
> On 19.08.2024 13:07, Frediano Ziglio wrote:
> > --- a/xen/common/efi/boot.c
> > +++ b/xen/common/efi/boot.c
> > @@ -287,19 +287,36 @@ static bool __init match_guid(const EFI_GUID *guid1, const EFI_GUID *guid2)
> > /* generic routine for printing error messages */
> > static void __init PrintErrMesg(const CHAR16 *mesg, EFI_STATUS ErrCode)
> > {
> > - static const CHAR16* const ErrCodeToStr[] __initconstrel = {
> > - [~EFI_ERROR_MASK & EFI_NOT_FOUND] = L"Not found",
> > - [~EFI_ERROR_MASK & EFI_NO_MEDIA] = L"The device has no media",
> > - [~EFI_ERROR_MASK & EFI_MEDIA_CHANGED] = L"Media changed",
> > - [~EFI_ERROR_MASK & EFI_DEVICE_ERROR] = L"Device error",
> > - [~EFI_ERROR_MASK & EFI_VOLUME_CORRUPTED] = L"Volume corrupted",
> > - [~EFI_ERROR_MASK & EFI_ACCESS_DENIED] = L"Access denied",
> > - [~EFI_ERROR_MASK & EFI_OUT_OF_RESOURCES] = L"Out of resources",
> > - [~EFI_ERROR_MASK & EFI_VOLUME_FULL] = L"Volume is full",
> > - [~EFI_ERROR_MASK & EFI_SECURITY_VIOLATION] = L"Security violation",
> > - [~EFI_ERROR_MASK & EFI_CRC_ERROR] = L"CRC error",
> > - [~EFI_ERROR_MASK & EFI_COMPROMISED_DATA] = L"Compromised data",
> > - [~EFI_ERROR_MASK & EFI_BUFFER_TOO_SMALL] = L"Buffer too small",
> > +#define ERROR_MESSAGE_LIST \
> > + ERROR_MESSAGE(EFI_NOT_FOUND, "Not found") \
> > + ERROR_MESSAGE(EFI_NO_MEDIA, "The device has no media") \
> > + ERROR_MESSAGE(EFI_MEDIA_CHANGED, "Media changed") \
> > + ERROR_MESSAGE(EFI_DEVICE_ERROR, "Device error") \
> > + ERROR_MESSAGE(EFI_VOLUME_CORRUPTED, "Volume corrupted") \
> > + ERROR_MESSAGE(EFI_ACCESS_DENIED, "Access denied") \
> > + ERROR_MESSAGE(EFI_OUT_OF_RESOURCES, "Out of resources") \
> > + ERROR_MESSAGE(EFI_VOLUME_FULL, "Volume is full") \
> > + ERROR_MESSAGE(EFI_SECURITY_VIOLATION, "Security violation") \
> > + ERROR_MESSAGE(EFI_CRC_ERROR, "CRC error") \
> > + ERROR_MESSAGE(EFI_COMPROMISED_DATA, "Compromised data") \
> > + ERROR_MESSAGE(EFI_BUFFER_TOO_SMALL, "Buffer too small")
> > +
> > + static const struct ErrorStrings {
>
> __initconst?
>
It's below, attached to the variable, it cannot be attached to a
structure declaration.
> > + CHAR16 start;
> > +#undef ERROR_MESSAGE
> > +#define ERROR_MESSAGE(code, str) CHAR16 msg_ ## code[sizeof(str)];
> > + ERROR_MESSAGE_LIST
> > + } ErrorStrings __initconst = {
Here it is.
> > + 0
> > +#undef ERROR_MESSAGE
> > +#define ERROR_MESSAGE(code, str) , L ## str
> > + ERROR_MESSAGE_LIST
> > + };
> > + static const uint16_t ErrCodeToStr[] __initconst = {
> > +#undef ERROR_MESSAGE
> > +#define ERROR_MESSAGE(code, str) \
> > + [~EFI_ERROR_MASK & code] = offsetof(struct ErrorStrings, msg_ ## code),
> > + ERROR_MESSAGE_LIST
> > };
> > EFI_STATUS ErrIdx = ErrCode & ~EFI_ERROR_MASK;
> >
> > @@ -308,7 +325,7 @@ static void __init PrintErrMesg(const CHAR16 *mesg, EFI_STATUS ErrCode)
> > PrintErr(L": ");
> >
> > if( (ErrIdx < ARRAY_SIZE(ErrCodeToStr)) && ErrCodeToStr[ErrIdx] )
> > - mesg = ErrCodeToStr[ErrIdx];
> > + mesg = (CHAR16*) ((char*) &ErrorStrings + ErrCodeToStr[ErrIdx]);
>
> Please never cast away const. Also (nit) please put the blanks at the right
> places. Finally instead of casting to char * (something string-like)
> intermediately, perhaps better cast to void *? Taken together
>
> mesg = (const CHAR16 *)((const void *)&ErrorStrings + ErrCodeToStr[ErrIdx]);
>
Done, less portable but it's not portable code.
> (which looks like it'll then also need line-wrapping).
>
> Further please add an appropriate Fixes: tag.
>
Done
> Jan
Frediano
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